Ground surface data generation method, ground surface data generation program, and ground surface data generation device

Abstract

To design a three-dimensional model of a ground surface including a plurality of structures by using parametric modeling, and to easily generate three-dimensional models of a ground plane and a slope face between the structures, especially the three-dimensional model of the slope face provided with a small step.SOLUTION: A ground surface data generation method includes, when generating a slope face having a small step, an acquisition step of further acquiring height data and width data of the small step. A surface generation step includes: a slope face generation step of generating a slope face from a section connection line that is a master in a master and servant relationship; a start point setting step of setting a plurality of small step start points on the slope face on the basis of the height data; a section line generation step of generating a section line for connecting the small step start points to each other; a deletion step of deleting, of two portions partitioned by the section line on the slope face, a portion not in contact with the section connection line; a ground plane generation step of generating a ground plane from the section line on the basis of the width data; and a second slope face generation step of defining the leading end of the ground plane as a new section connection line and generating a new slope face from the new section connection line.SELECTED DRAWING: Figure 38

Description

[Technical field]

[0001] The present invention relates to a ground surface data generating method, a ground surface data generating program, and a ground surface data generating device. [Background technology]

[0002] In the civil engineering industry, the mainstream 3D model design is direct modeling, in which a frame that constitutes a mesh is generated first, and then a mesh is generated within that frame to create a 3D model. In direct modeling, frames are independent of each other, so for example, when modifying the elevation of a structure, all related frames must be manually modified and the mesh must be regenerated, which is quite time-consuming. In addition, designing 3D models using direct modeling has problems such as the complicated drawing procedures that make it difficult for beginners to undertake, or the time it takes to improve one's skills.

[0003] On the other hand, parametric modeling is a method of generating a three-dimensional model by expressing the arrangement of a structure with a skeleton line and assigning parameters that define the shape to the skeleton line. In parametric modeling, the shape of the three-dimensional model can be changed by changing the parameters. In parametric modeling, the position of the three-dimensional model can also be changed by changing the position of the skeleton line. With this method, the shape of the three-dimensional model can be easily modified just by changing the parameters. As a design technique for a three-dimensional model using such parametric modeling, for example, a CAD system that generates a three-dimensional shape of a target object using a two-dimensional drawing, as described in Patent Document 1, has been known. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 09-022421 Summary of the Invention [Problem to be solved by the invention]

[0005] However, with conventional 3D model design technology using parametric modeling, while it was possible to generate 3D models of each individual structure, it was not possible to control ground surface data such as the ground surface and slopes constructed between structures, particularly slopes with berms.

[0006] One aspect of the present invention has been made in consideration of the above-mentioned problems, and aims to enable easy generation of 3D models of the ground surface and slopes between structures, in particular slopes with berms, when designing a 3D model of the ground surface including multiple structures using parametric modeling. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, a ground surface data generation method according to one embodiment of the present invention is a ground surface data generation method for generating three-dimensional ground surface data between a plurality of structures, the method including: an acquisition step for acquiring skeleton line data defining a skeleton line consisting of a two-dimensional or three-dimensional oriented polyline or oriented polygon having a starting point and an end point, and discrete elevation data of the structures; a connection line generation step for generating a three-dimensional connection line showing the outer shape of the structures from the skeleton line based on shape data defining the shape of the structures; a shared connection line generation step for generating a single shared connection line by connecting section connection lines separated by a common point that is the intersection point on a vertical projection plane of two of the connection lines; a pairing search for searching for connection lines outside the shared connection line from the shared connection line, and setting the section connection lines that have been paired as pair connection lines; and a pairing step for extracting a slope or ground surface from each of the pair connection lines based on pair information indicating a master-slave relationship of each of the section connection lines included in the pair connection lines. and a surface generating step of generating a slope having a berm as the slope, wherein in the case of generating a slope having a berm as the slope, the obtaining step further obtains height data and width data of the berm, and the surface generating step includes the following steps: a slope generating step of generating a slope from the section connection line whose master-slave relationship in the pair connection line is the master; a start point setting step of setting a plurality of berm start points which will be starting points for generating berms on the slope based on the height data; a deleting step of generating demarcation lines connecting the plurality of berm start points; a deletion step of deleting one of two parts of the slope separated by the demarcation line which is not in contact with the section connection line; a ground surface generating step of generating a ground surface which is horizontal or inclined less than the gradient of the slope from the demarcation line based on the width data, so as to have a width indicated by the width data; and a second slope generating step of setting a ground edge line which forms the tip of the ground surface as a new section connection line, and generating a new slope from the new section connection line.

[0008] Furthermore, a ground surface data generation program according to another aspect of the present invention is a ground surface data generation program that causes a computer to generate three-dimensional ground surface data between a plurality of structures, and includes the following steps: an acquisition step in which the computer acquires skeleton line data defining a skeleton line consisting of a two-dimensional or three-dimensional oriented polyline or oriented polygon having a starting point and an end point, and discrete elevation data of the structures; a connection line generation step in which a three-dimensional connection line showing the outer shape of the structures is generated from the skeleton line based on shape data defining the shape of the structures; a shared connection line generation step in which section connection lines separated by a common point that is the intersection point on a vertical projection plane of two of the connection lines are connected to generate a single shared connection line; a pairing search step in which the shared connection line is searched for a connection line outside the shared connection line, and the section connection lines that are paired are treated as paired lines; and a pairing step in which the computer acquires information indicating a master-slave relationship of each of the section connection lines included in the pair connection lines, and the information indicates the relationship between the pair connection lines. and a surface generating step of generating a slope or a ground surface from the respective data. In the case where a slope having a berm is to be generated as the slope, the acquisition step further acquires height data and width data of the berm, and the surface generating step executes the following steps: a slope generating step of generating a slope from the section connection line whose master-slave relationship in the pair connection line is the master; a start point setting step of setting a plurality of berm start points which will be start points for generating berms on the slope based on the height data; a deletion step of dividing the slope with a division line connecting the plurality of berm start points and deleting one of the two divided parts which is not in contact with the section connection line; a ground surface generating step of generating a ground surface which is horizontal or inclined less than the gradient of the slope from the division line based on the width data so as to have a width indicated by the width data; and a second slope generating step of setting a ground edge line which forms the tip of the ground surface as a new section connection line and generating a new slope from the new section connection line.

[0009] Furthermore, a ground surface data generating device according to another aspect of the present invention is a ground surface data generating device that generates three-dimensional ground surface data between a plurality of structures, and includes an acquisition unit that acquires skeleton line data that defines a skeleton line consisting of a two-dimensional or three-dimensional oriented polyline or oriented polygon having a starting point and an end point, and discrete elevation data of the structures, a connection line generation unit that generates a three-dimensional connection line that shows the outline of the structures from the skeleton line based on shape data that defines the shape of the structures, a shared connection line generation unit that generates a single shared connection line by connecting section connection lines separated by a common point that is the intersection point on a vertical projection plane of two of the connection lines, a pairing unit that executes a pairing search that searches for connection lines outside the shared connection line from the shared connection line, and sets the section connection lines that are paired as paired lines, and a pairing unit that extracts slopes or and a surface generation unit that generates a ground surface. In the case of generating a slope having a berm as the slope, the acquisition unit further acquires height data and width data of the berm, and the surface generation unit comprises: a slope generation unit that generates a slope from the section connection line in which the master-slave relationship in the pair connection lines is master; a start point setting unit that sets a plurality of berm start points on the slope based on the height data as starting points for generating berms; a division line generation unit that generates division lines connecting the plurality of berm start points; a deletion unit that deletes the one of two parts of the slope separated by the division line that is not in contact with the section connection line; a ground surface generation unit that generates a ground surface that is horizontal or inclined less than the gradient of the slope from the division line based on the width data, so that the width is indicated by the width data; and a second slope generation unit that sets a ground edge line that forms the tip of the ground surface as a new section connection line and generates a new slope from the new section connection line. Effect of the Invention

[0010] According to one aspect of the present invention, when designing a three-dimensional model of the ground surface including multiple structures using parametric modeling, it is possible to easily generate three-dimensional models of the ground surface and slopes between the structures, in particular three-dimensional models of slopes with berms. [Brief description of the drawings]

[0011] [Figure 1] 1 is a diagram showing an example of a two-dimensional model based on two-dimensional CAD data used in the earth's surface data generation method according to an embodiment of the present invention; [Diagram 2] 1 is a block diagram showing a functional configuration of an earth's surface data generating device used in an earth's surface data generating method according to a first embodiment of the present invention. [Diagram 3] 4 is a flowchart showing the flow of a ground surface data generation process executed by the device. [Figure 4] FIG. 2 is a diagram showing an example of a shape data input screen displayed by the device. [Diagram 5] 11 is a diagram illustrating an example of a process for generating a shared connection line executed by the device. [Figure 6] FIG. 2 is a diagram showing an example of an intersection model generated by the device. [Figure 7] FIG. 2 is a diagram showing an example of a pairing search performed by the device. [Figure 8] FIG. 2 is a diagram showing an example of pairing search using the Kushi-dango method performed by the device. [Figure 9] FIG. 2 is a diagram showing an example of pairing search using the Kushi-dango method performed by the device. [Figure 10] FIG. 2 is a diagram showing an example of pairing search using the Kushi-dango method performed by the device. [Figure 11] FIG. 2 is a diagram showing an example of pairing search using the Kushi-dango method performed by the device. [Figure 12] FIG. 2 is a diagram showing an example of pairing search using the Kushi-dango method performed by the device. [Figure 13] FIG. 2 is a diagram showing an example of a switching line generated by the device. [Figure 14] FIG. 2 is a diagram showing an example of a three-dimensional model based on three-dimensional CAD data generated by the device. [Figure 15] FIG. 2 is a diagram showing an example of a method for measuring the slope of a slope performed by the device. [Figure 16]11A to 11C are diagrams illustrating an example of a method for generating a reference line executed by the apparatus. [Figure 17] FIG. 11 is a block diagram showing the functional configuration of a device for generating mesh data for design and construction used in a method for generating mesh data for design and construction according to a second embodiment of the present invention. [Figure 18] 4 is a flowchart showing the process of generating mesh data for design and construction performed by the device. [Figure 19] FIG. 11 is a diagram explaining the shape data of a drainage channel required for generating mesh data for design and construction. [Figure 20] FIG. 13 is a diagram for explaining shape data at the road construction stage that is required for generating mesh data for design and construction. [Figure 21] FIG. 13 is a diagram showing an example of a shape data input screen displayed by the device during the drainage channel construction stage. [Figure 22] This is a schematic diagram showing an example of a screen on which mesh data for the base surface, cultivated surface, and ridges used in field leveling work is generated. [Diagram 23] FIG. 11 is a block diagram showing a configuration of a top surface generating device 3 according to a third embodiment of the present invention. [Figure 24] 13 is a flowchart showing a flow of a top surface generating method S30 executed by the top surface generating device 3. [Diagram 25] 13 is a schematic diagram showing data on nodes of ground edge lines of a road acquired by an acquisition unit 351 of the top surface generation device 3. FIG. [Figure 26] 1 is a schematic diagram showing a slope generated by a slope generating unit 352 of the top surface generating device 3. FIG. [Figure 27] 13 is a flowchart showing the flow of a plane extraction method S33 executed by an extraction unit 353 of the top surface generation device 3. [Figure 28] This is a schematic diagram showing how a twisted slope is divided into two triangles between opposing vertices. [Figure 29] 1 is a schematic diagram showing a plane passing through three points A, B, and C. [Diagram 30] 1 is a schematic diagram showing a distance L between a plane passing through three points A, B, and C and a point D. [Diagram 31]FIG. 1 is a diagram showing an example of an intersection where three slopes overlap. [Diagram 32] FIG. 4 is a schematic diagram showing where derived intersection points overlap with existing points shown in FIG. 3 . [Diagram 33] 13 is a schematic diagram showing an example of points to be integrated among intersections or existing vertices; FIG. [Diagram 34] FIG. 13 is a schematic diagram showing a vertex located below the uppermost slope. [Diagram 35] FIG. 13 is a schematic diagram showing a method for determining whether ground edge lines intersect with each other and generating a new ground edge line if the ground edge lines intersect with each other; [Diagram 36] FIG. 11 is a block diagram showing a functional configuration of an earth surface data generating device 1A used in an earth surface data generating method according to a fourth embodiment of the present invention. [Figure 37] 2 is a block diagram showing a functional configuration of a surface generating unit 161A included in the earth's surface data generating device 1A. FIG. [Figure 38] FIG. 2 is a schematic diagram showing a part of a process in which the earth's surface data generating device 1A generates data on a stepped slope. [Figure 39] FIG. 2 is a schematic diagram showing a part of a process in which the earth's surface data generating device 1A generates data on a stepped slope. [Diagram 40] FIG. 2 is a schematic diagram showing a part of a process in which the earth's surface data generating device 1A generates data on a stepped slope. [Diagram 41] FIG. 2 is a schematic diagram showing a part of a process in which the earth's surface data generating device 1A generates data on a stepped slope. [Diagram 42] FIG. 2 is a schematic diagram showing a part of a process in which the earth's surface data generating device 1A generates data on a stepped slope. [Diagram 43] FIG. 2 is a schematic diagram showing a part of a process in which the earth's surface data generating device 1A generates data on a stepped slope. [Diagram 44] FIG. 2 is a schematic diagram showing a part of a process in which the earth's surface data generating device 1A generates data on a stepped slope. [Diagram 45] FIG. 2 is a schematic diagram showing a part of a process in which the earth's surface data generating device 1A generates data on a stepped slope. [Figure 46]FIG. 2 is a schematic diagram showing a part of a process in which the earth's surface data generating device 1A generates data on a stepped slope. [Figure 47] 1 is a flowchart showing a flow of an earth surface data generating method executed by an earth surface data generating method 1A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] [Embodiment 1] Hereinafter, one embodiment of the present invention will be described in detail.

[0013] [2D CAD data] First, we will explain two-dimensional CAD data, which is one type of CAD data read by the earth surface data generating device 1 described later. The two-dimensional CAD data used here is composed of multiple layers. Each layer has one or more polylines or polygons that constitute structures drawn. A "structure" includes one or more of roads, farm fields, irrigation channels, drainage channels, access roads from roads to farm fields, parking lots, housing sites, levees, concrete retaining walls, tunnels, pipelines, railway embankments, breakwaters, revetments, and seawalls. One layer may include only one type of structure.

[0014] (Layer) A layer name is given to each layer. In the two-dimensional CAD data according to this embodiment, the plan, work type, and ID are used as layer names. In the "plan", "current state" or "plan" is written. "Current state" means the current (before construction) state of the structure. "Plan" means the state after the completion of the structure. Note that there may be multiple plans (for example, plan 1, plan 2, plan 3, etc.) for one structure. "Work type" is the name of the structure (road, waterway, etc.). "ID" is information for identifying one polyline or polygon that constitutes the structure indicated by the work type. Therefore, the layer name of the two-dimensional CAD data according to this embodiment is written, for example, as "Plan_Road_ID1". The plan, work type, and ID written as the layer name are treated as attribute data in the earth surface data generation device 1 described later.

[0015] (Polyline / Polygon) Among structures, roads, irrigation channels, drainage channels, etc. are drawn using polylines. The order in which the polylines were drawn (the direction in which the lines of the polylines were drawn, and the starting point and the end point) is linked to the polylines. As a result, when the earth surface data generating device 1 reads this 2D CAD data, the polylines become directed polylines, and it becomes possible to distinguish between the right and left sides of the polylines. Meanwhile, among structures, structures that are surrounded by boundaries (farm fields, parking lots, housing sites, etc.) are drawn as polygons. Polygons are basically drawn in a single stroke in a clockwise or counterclockwise direction. However, information indicating which direction the polygons were drawn in is not linked to the polygons (it is not possible to determine the order in which the polygons were drawn). This is because the earth surface data generating device 1 has a function of performing a process of unifying the order of directions of the polygons that it reads.

[0016] (Elevation Identifier) Character information can be written on each layer of the two-dimensional CAD data. The two-dimensional CAD data used here has an elevation identifier and a number written on each layer. The elevation identifier is a symbol indicating that the elevation at the point on the polyline or polygon closest to the position (center point) where it is written is represented by the number written together. One or more pairs of an elevation identifier and a number are written for one polyline. The elevation identifier according to this embodiment is a figure such as a circle or a double circle, and indicates the elevation of the center point of the figure. The shape of the elevation identifier is not limited to a circle or a double circle. The figure may be a square or an equilateral triangle, etc., as long as the center point is easily determined. In addition, when other elevation values ​​are densely written and it is difficult to write the elevation value near the figure, a leader line is also used as the elevation identifier. In this case, when the leader line is also used, it is necessary to distinguish between the skeleton line and the leader line. In the two-dimensional CAD data according to this embodiment, the base end of the leader line is drawn so as to be inside the figure. Then, the elevation value is written near the tip of the leader line.

[0017] Furthermore, there are two types of lines handled by CAD: polylines and line segments. A polyline is a line that connects two or more points from a starting point to an end point, while a line segment is a straight line that always has only two points, a starting point and an end point, and they are each handled as having different attributes. By utilizing this characteristic, in this embodiment, skeleton lines are drawn as polylines, and leader lines are drawn as line segments. In addition, it is also possible to use the color information of the lines. For example, if the skeleton lines are specified as blue and the leader lines are specified as red, then when reading this data, it is possible to distinguish between the skeleton lines and the leader lines.

[0018] The number indicating the elevation is written near (within a specified distance from) the center point of the elevation identifier, or near the end point of the lead line. The number indicating the elevation of a structure represented by a polygon is written inside the polygon. In this case, particularly when the structure is a rice paddy, one elevation identifier and number combination is sufficient since the elevation within the paddy is uniform. Note that by writing such an elevation identifier and number combination in the two-dimensional CAD data, the earth surface data generation device 1 becomes able to obtain elevation information from two-dimensional CAD data that cannot have three-dimensional information.

[0019] If the structure is a paddy field, ridges are required around the periphery to store water on the surface of the field, but no elevation identifier or number is written on the ridges. This is because the earth surface data generating device 1 automatically determines the elevation of the ridges from the elevation of the paddy field surface.

[0020] (Cross-identifier) Two roads or waterways that extend in different directions may intersect. An intersection may be a real intersection that actually intersects with another, or a multi-level intersection that does not actually intersect with another (one of the roads or waterways becomes an underpass). Therefore, in the two-dimensional CAD data used here, an intersection identifier is described as necessary at the intersection of each road and each waterway described in each layer. The intersection identifier is a symbol indicating that the intersection is a multi-level intersection. The intersection identifier according to this embodiment is a figure with a shape (e.g., a square, etc.) different from the elevation identifier. The intersection identifier may be a symbol indicating that the intersection is a real intersection. By describing such an intersection identifier in the two-dimensional CAD data, the ground surface data generation device 1 can obtain information on whether the intersection is a real intersection or a multi-level intersection from the two-dimensional CAD data that cannot have three-dimensional information.

[0021] (Other Identifiers) In addition, among multiple waterways, there are cases where some share their respective end points and become a single waterway. In these cases, the elevations of each waterway may differ. Therefore, the 2D CAD data used here includes identifiers indicating that a manhole will be installed at the connection points (where the elevations are different) of each waterway listed on each layer. In this case, a drop work is required to install manholes at different elevations.

[0022] By overlaying layers containing polylines, polygons, etc. according to the above rules, a 2D model of the structure to be constructed, as shown in Figure 1, is obtained. Note that some parts have been omitted in Figure 1 to avoid complexity. For example, the elevation identifier mentioned above exists near the elevation value, but is not shown in Figure 1. Also, while information from multiple layers is overlaid in Figure 1, since the type of numerical value is determined on each layer, it is sufficient that an identifier is written so that the type of numerical value can be determined on each layer.

[0023] [Embodiments of Earth surface data generation method, device, and program] Next, a ground surface data generation method, device, and program will be described. The ground surface data generation device 1 described here is used when implementing the ground surface data generation method according to an embodiment of the present invention. The ground surface data generation method is a method for generating three-dimensional ground surface data between a plurality of structures. As shown in FIG. 2, the ground surface data generation device 1 includes an input unit 11, an operation unit 12, an output unit 13, a storage unit 14, and a control unit 15.

[0024] (Input section) Two-dimensional CAD data or three-dimensional CAD data is input to the input unit 11. The input unit 11 is composed of, for example, a terminal to which a cable connected to a device in which the data is stored is connected, a communication unit that communicates with the device in which the data is stored by wire or wirelessly, or a drive that reads a medium in which the data is stored.

[0025] [Operation unit] The operation unit 12 receives various input operations by a user and is configured with a keyboard, a mouse, a touch panel, or a dedicated device.

[0026] (Output section) The output unit 13 according to this embodiment outputs the generated 3D model. The output unit 13 is composed of, for example, a terminal to which a cable connected to a monitor is connected, a communication unit that communicates with other devices by wire or wirelessly, or a drive that writes data of the 3D model to a medium. The output unit 13 may be the monitor itself that displays the 3D model based on the data.

[0027] (Storage part) The storage unit 14 stores an earth surface data generation program 141. The earth surface data generation program 141 describes the flow of the earth surface data generation process executed by the control unit 15. The storage unit 14 according to this embodiment is configured with a semiconductor memory or a hard disk. Note that when the earth surface data generation program is not required (for example, when the control unit 15 performs all of the various calculations described below using logic circuits), the earth surface data generation device 1 does not need to be provided with the storage unit 14.

[0028] (Control unit) The control unit 15 includes an acquisition unit 151, a second acquisition unit 152, an interpolation unit 153, a global order setting unit 154, a determination unit 155, a connection line generation unit 156, a shared connection line generation unit 157, a pairing unit 158, a pair information setting unit 159, a switching line generation unit 160, a surface generation unit 161, a warning information extraction unit 162, a data output processing unit 163, and a change unit 164. The control unit 15 according to the present embodiment is configured with a processor. The control unit 15 executes a ground surface data generation process as shown in FIG. 3 according to the ground surface data generation program stored in the storage unit 14. The ground surface data generation process includes an acquisition step S1, a connection line generation step S6, a shared connection line generation step S7, a pairing step S8, and a surface generation step S11. The earth surface data generation process may further include a second acquisition step S2, an interpolation step S3, a global order setting step S4, a determination step S5, a pair information setting step S9, a switching line generation step S10, a warning information extraction step S12, a data output step S13, and a change step S14. Each step in the earth surface data generation process corresponds to each step included in the earth surface data generation method according to this embodiment.

[0029] (1. Acquisition step) In the first acquisition step S1, the acquisition unit 151 acquires skeleton line data. The skeleton line data is data that defines the skeleton line L1. The skeleton line is a line that is a reference line of a structure, and is defined as, for example, the center line of the road in the case of a road, and the center line of the ridge in the case of a rice field. In the case of a waterway, it is, for example, the center line of the bottom surface of the waterway. The skeleton line data is data that defines the skeleton line, and includes position data, elevation data, ID, type, etc. Each skeleton line L1 is made up of a two-dimensional or three-dimensional oriented polyline or oriented polygon having a starting point and an end point. The skeleton line data according to this embodiment is vector data included in two-dimensional CAD data or three-dimensional CAD data. When skeleton line data including a polygon (annular skeleton line L1) is acquired, the acquisition unit 151 analyzes the starting point and the end point of the polygon and corrects the winding order to a predetermined direction. This unifies the winding order of the acquired polygon. Then, by unifying the winding order, the control unit 15 becomes able to distinguish the inside and outside of the polygon by calculating the cross product.

[0030] In the acquisition step S1, the acquisition unit 151 acquires discrete elevation data of the structure. Specifically, the acquisition unit 151 identifies an elevation identifier written on a layer. Then, the acquisition unit 151 acquires a skeleton line of the structure recorded on the same layer, and an elevation identifier (predetermined mark) and a number (elevation data) written at a predetermined position on the layer. For example, the elevation identifier may be placed on the skeleton line. Then, the acquisition unit 151 judges whether or not a leader line is drawn on the identified elevation identifier. Here, if it is judged that a leader line is not drawn, the acquisition unit 151 records the number closest to the elevation identifier as an elevation value, linked to the position of the elevation identifier. On the other hand, if it is judged that a leader line is drawn on the elevation identifier, the acquisition unit 151 records the number written closest to the tip of the leader line as an elevation value, linked to the position of the elevation identifier. Note that, if the skeleton line data to be acquired is included in the three-dimensional CAD data, the elevation data is included in the skeleton line data, so that the acquisition unit 151 only needs to acquire the skeleton line data.

[0031] In the acquisition step S1, the acquisition unit 151 acquires intersection data. Specifically, the acquisition unit 151 identifies intersection identifiers written on roads or waterways on the layer. Then, the acquisition unit 151 records an intersection with an intersection identifier written thereon as a multilevel intersection. The acquisition unit 151 records an intersection without an intersection identifier written thereon as an actual intersection.

[0032] In the acquisition step S1, when drawing the skeleton line L1 of the intersection, the acquisition unit 151 may draw the section that will be an underpass with a broken line. In that case, it is preferable that the acquisition unit 151 draws the broken line section longer than the actual section, taking into consideration the case where the generated three-dimensional model is corrected.

[0033] In addition, among the multiple skeleton lines L1, there may be some that share their respective end points and become one skeleton line L1. For example, when the structure is a road (waterway), a narrow road (waterway) and a wide road (waterway) are connected to each other. An intersection generally refers to a place where two or more skeleton lines L1 intersect, but the acquisition unit 151 according to the present embodiment recognizes a case where the respective end points are shared as a two-way intersection. The reason for having the acquisition unit 151 recognize the intersection as a two-way intersection is to make the intersection (end point) have the same elevation. In other words, when it is not possible to recognize it as a two-way intersection, in the case of roads, the elevation at the end points is different, and there is a risk that a road for which an intersection is not generated will be generated. Note that the earth surface data generation device 1 may be provided with an intersection generation unit (not shown) that generates an intersection model for a multi-way intersection, including a two-way intersection. An ID is assigned to each intersection, and a corner cutting length, etc. may be input as a shape parameter for each ID, so that the intersection shape can be changed based on the shape parameter.

[0034] Furthermore, when generating oriented polygons for two fields that share a ridge, it is necessary to draw oriented polygons for each field. However, in two-dimensional CAD data, the ridge between the two fields is drawn with one skeleton line L1. For this reason, when generating the skeleton line L1 from the two-dimensional CAD data while tracing the polyline of the field, the acquisition unit 151 according to this embodiment selects a polyline that extends in a predetermined direction (right or left) toward the traveling direction when it approaches an intersection where the polyline of each field and the polyline of the ridge intersect, and extends the skeleton line L1. This makes it possible to generate the skeleton line L1 (oriented polygon) for each field, even if topographical data for two fields that share a ridge is acquired. Alternatively, one ridge between two fields may be assigned to each field, and each of the two ridges may be drawn using two skeleton lines L1.

[0035] In the earth surface data generation process according to this embodiment, in the acquisition step S1, the acquisition unit 151 further acquires attribute data of the structure. The attribute data of the structure includes at least one of the layer name, the construction type of the structure, and the ID of the structure. In two-dimensional CAD data, attribute data (ID, name, etc.) cannot be directly assigned to the skeleton line L1. For this reason, in the two-dimensional CAD data used here, each skeleton line L1 is arranged on a different layer. Then, the acquisition unit 151 links the layer name (attribute data of each skeleton line L1) assigned to each layer to the skeleton line L1 described on each layer. When multiple skeleton lines are described on the same layer, the acquisition unit 151 links the same attribute data to each of the multiple skeleton lines L1.

[0036] The acquisition unit 151 may be configured to acquire three-dimensional point cloud data and generate skeleton line data and elevation data of a structure from a plurality of coordinate values ​​(x, y, z) included in the three-dimensional point cloud data. The three-dimensional point cloud data is survey data obtained based on photos of the ground surface taken by a UAV (Unmanned Aerial Vehicle), an aircraft, an artificial satellite, etc., and reflected laser light from the ground surface collected by these. In this case, the acquisition unit 151 first reproduces a point cloud based on the acquired three-dimensional point cloud data in a three-dimensional space. Then, the acquisition unit 151 recognizes a structure from the reproduced point cloud, and draws a skeleton line L1 of the structure on a layer to which a corresponding layer name (plan, type of work, and ID) is assigned. The recognition of the structure and the drawing of the skeleton line L1 may be performed by a user.

[0037] (2. Second acquisition step) In the earth surface data generating method according to this embodiment, after acquiring the skeleton line data and the elevation data and before executing the connection line generating step S6 described later, the process proceeds to a second acquisition step S2. In the second acquisition step S2, the second acquisition unit 152 acquires shape data of the structure. The shape data is parameters that define the shape of the structure. In this embodiment, the structure is represented by a parametric model. In other words, the shape data is parameter data that defines the shape of the parametric model. The second acquisition unit 152 may further acquire material data and ground data. The material data is data that indicates the material of the structure, the presence or absence of vegetation, etc. The ground data is data related to the base layer, the cultivated layer, etc.

[0038] For example, if the structure is a road, the shape data includes basic parameters, slope parameters, ground surface parameters, and berm parameters. The basic parameters include the effective width (distance from the skeleton line L1 to the edge of the road surface), left shoulder (distance from the skeleton line L1 to the left berm), right shoulder (distance from the skeleton line L1 to the right berm), width height, and roadbed surface height. The material parameters include the material of the road and the presence or absence of vegetation on the slope. The slope parameters include the gradient of the right slope and the gradient of the left slope. The ground surface parameters include the width of the ground surface, etc. The berm parameters include the presence or absence of berms on the slope, and if there are berms, the number of berms installed, the installation height of each berm, and the width of each berm.

[0039] If the structure is an irrigation canal, the shape data includes basic parameters, slope parameters, ground surface parameters, and berm parameters. The basic parameters include flume width, flume height, foundation concrete width, foundation concrete height, bed mortar height, left irrigation canal shoulder, and right irrigation canal shoulder. The slope parameters include the gradient of the right side slope and the gradient of the left side slope. The ground surface parameters include the width of the ground surface, etc. The berm parameters include the presence or absence of berms on the slope, and if there are berms, the number of berms installed, the installation height of each berm, and the width of each berm.

[0040] The second acquisition unit 152 according to the present embodiment acquires shape data from the operation unit 12 when the user performs an input operation on the operation unit 12 while an input screen such as that shown in FIG. 4 is displayed. The second acquisition unit 152 then links the acquired shape data to the corresponding skeleton line. When multiple skeleton lines are drawn on the same layer, the second acquisition unit 152 links the same shape data to each of the multiple skeleton lines. When an input operation is performed on a real intersection, the second acquisition unit 152 acquires shape data of an intersection model. Then, regardless of whether each skeleton line constituting the real intersection is drawn on the same layer or not, each skeleton line is linked to shape data that defines the shape of the intersection. However, for the road width and the like among the shape data, the shape data linked to the original skeleton line L1 is taken over. When the structure is a paddy field, settings related to the ridges can be made on the input screen. Therefore, when the structure is a paddy field, the second acquisition unit 152 acquires information on the ridges in addition to the shape data. This second acquisition step S is repeated until the second acquisition unit 152 acquires shape data for all skeleton lines L1.

[0041] The shape data may not be obtained by inputting the shape data into the operation unit 12, but may be read from another device, a recording medium, etc. (obtained by previously accepted inputting the shape data and outputted to another device, a recording medium, etc.). In this way, the user can be spared the trouble of inputting the shape data in the second acquisition step S2. In this case, the shape data may be obtained together with the skeleton line data and the elevation data in the acquisition step S1. In this case, the second acquisition step is unnecessary.

[0042] (3. Interpolation step) In the earth surface data generating method according to the present embodiment, after generating the shared connection line L3, the process proceeds to an interpolation step S3 as shown in FIG. 3. In the interpolation step S3, the interpolation unit 153 generates points at an arbitrary interval within and / or outside the section on the skeleton line L1 between two points linked with the elevation data. The interval is preferably within a range of 1 to 10 m in a straight section of the skeleton line L1, and within a range of 0.3 to 5 m in a broken line section in which a plurality of skeleton lines L1 are connected. Then, the interpolation unit 153 allocates an elevation value to each of the generated points based on the elevation value indicated by the elevation data linked to both ends of the section. If the location where the point is generated is within the section between two points, the elevation value is allocated by interpolation (linear interpolation). On the other hand, if the location is outside the section, the elevation value is allocated by extrapolation.

[0043] When two or more skeleton lines L1 intersect to form a real intersection and the elevation value of the real intersection is to be allocated, the interpolation unit 153 performs allocation by linear interpolation for each skeleton line L1. It is preferable that the elevation values ​​obtained by each allocation are the same, but in many cases, these elevation values ​​are different. Therefore, the interpolation unit 153 adjusts the elevation value of the real intersection using a weighting that is set in advance for each skeleton line L1 (directed polyline). For example, when there are two intersecting skeleton lines and the weighting of each skeleton line L1 is set to 0.5:0.5, the interpolation unit 153 takes the average of the obtained elevation values. Also, when the weighting of each skeleton line L1 is set to 1:0, the interpolation unit 153 sets the elevation value obtained for the skeleton line L1 with the weighting set to 1 as the elevation value of the real intersection.

[0044] The weight of the skeleton line L1 may be set by the user or according to a predetermined rule. For example, when the skeleton line L1 is that of a road, the predetermined rule is set based on the width of the road. Specifically, when the difference in width between the intersecting roads is sufficiently large, the weight of the road with the larger width is made relatively large. In particular, when the intersecting roads are a main trunk road and a branch road, it is common to match the elevation of the main trunk road, so the weight of the main trunk road is set to 1 and the weight of the branch road is set to zero.

[0045] When the elevation value of a real intersection is adjusted, the elevation value of the points on the skeleton line L1 is redone. In this case, since the elevation value of the adjusted real intersection should not be changed, the elevation data is allocated within the section between the point linked to the real intersection. In other words, the elevation points of the adjusted real intersection are referenced to redeploy the elevation points of the points on the skeleton line L1.

[0046] (4. Global ranking setting step) After acquiring the skeleton line data and the elevation data, the process proceeds to a global order setting step S4. In the global order setting step S4, the global order setting unit 154 sets an overall global order for each skeleton line L1 of each structure. In the global order setting step S4 according to this embodiment, the global order setting unit 154 sets the order in accordance with a predetermined ordering rule. The ordering rule used here is as follows: All road skeleton lines L1: 1st All irrigation channels: 2nd place Fields (including ridges): 3rd to N-1 in order of altitude All drainage channels: Nth rank (lowest)

[0047] The reason why the skeleton line L1 of the road has the first global ranking is because roads in farmland are installed at a higher position than the surrounding fields, and slopes often extend from the left and right connecting lines L2 of the skeleton line L1 of the road. On the other hand, the skeleton line L1 of the drainage channel has the lowest global ranking because drainage channels are installed at a lower position than the surrounding fields, and often intersect with slopes extending from roads and fields. Also, the skeleton line L1 of the irrigation channel has the second global ranking because irrigation channels are often installed at a higher altitude than the fields. Also, the skeleton line L1 of the field is assigned a global ranking in descending order of altitude because slopes extend from high-altitude fields to low-altitude fields. By setting such global rankings, in the surface generation step S11 described later, a slope is generated from the side of the skeleton line with a high global ranking to the side of the skeleton line with a low global ranking. Also, a ground surface is generated from the side of the skeleton line with a lower global order. The ground surface is generated at a certain length from the connecting line. After the ground surface is generated, a downward slope is generated on the outside of the ground surface up to the base ground surface. Also, between skeleton lines with the same global order, processing is performed using pair information, which will be described later.

[0048] The global order may be freely set by the user. Furthermore, when a model of a new structure is additionally generated in a three-dimensional model after the generation of the three-dimensional model, the user may set an arbitrary global order for the skeleton line L1 corresponding to the new structure, or the global order setting unit 154 may automatically assign a global order according to the type of work. The model may be regenerated by the user changing the global order.

[0049] (5. Judgment step) In the ground surface data generating method according to the present embodiment, if the acquired CAD data is two-dimensional CAD data, the process proceeds to a determination step S5 after setting the global order. In the determination step S5, the determination unit 155 determines whether an intersection of multiple skeleton lines L1 in the acquired CAD data is an actual intersection that actually intersects (if the two skeleton lines L1 are each roads, it becomes an intersection) or a multi-level intersection that does not actually intersect (if the two skeleton lines L1 are each roads, one road becomes an underpass). Specifically, the determination unit 155 determines whether an intersection identifier (a predetermined mark (such as a rectangle)) is attached to the intersection of the skeleton lines L1 included in the two-dimensional CAD data. If an intersection identifier is attached, the determination unit 155 determines that the intersection is a multi-level intersection. On the other hand, if an intersection identifier is not attached, the determination unit 155 determines that the intersection is an actual intersection.

[0050] (6. Connection line generation step) After acquiring the skeleton line data and the elevation data, or after determining the intersections of the skeleton line L1, the process proceeds to a connection line generating step S6, in which the connection line generating unit 156 generates a three-dimensional connection line L2 indicating the outline of the structure from the skeleton line L1 based on the shape data.

[0051] When the input of the shape data is accepted, the connection line generating unit 156 generates a connection line L2 based on the position and shape data of the skeleton line L1. When the skeleton line L1 is a road, a waterway, or the like (the skeleton line L1 is a directed polyline), the connection line generating unit 156 generates a pair of connection lines L2, L2. Specifically, the connection line L2 (such as the connection line L2 indicating the slope) is generated on the right and left sides of the direction of the directed polyline, which is parallel to the directed polyline. When the skeleton line L1 is a directed polyline, the connection line generating unit 156 further generates a pair of end lines. Specifically, the connection line generating unit 156 generates end lines that pass through both ends of the skeleton line L1 and connect both ends of the pair of connection lines L2 that sandwich the skeleton line L1. Then, the connection line generating unit 156 assigns an ID to each generated connection line L2.

[0052] Paddy fields have ridges on the periphery because they need to store water on the surface of the field. Therefore, when the structure is a paddy field, the connection line generating unit 156 calculates the elevation of both ends of the ridge based on the elevation data of the paddy field surface, and generates a ridge skeleton line L1 of the paddy field based on the paddy field skeleton line L1 (polygon) and the calculated elevations of both ends of the ridge. The connection line generating unit 156 then generates a connection line L2 of the ridge based on the ridge skeleton line L1 and shape data that defines the shape of the ridge.

[0053] When the operation unit 12 receives an instruction from the user to generate a model of a structure other than the structure indicated by the skeleton lines L1 at the intersection of the two skeleton lines L1 (for example, a corner cut if the structure is a road, or a manhole if the structure is a waterway), the connection line generation unit 156 generates a connection line for the other structure based on the input shape data.

[0054] In addition, for structures that are recognized as a two-way intersection consisting of two roads (waterways) of different widths, an adjustment section is set up on either side of the intersection, and a connecting line L2 is generated within the adjustment section so that the width changes continuously from one road (waterway) to the other road (waterway), thereby smoothly connecting one road (waterway) to the other road (waterway).

[0055] (7. Shared connection line generation step) After generating the connection line L2, the process proceeds to a shared connection line generation step S7 as shown in FIG. 3. The shared connection line is a connection line for performing a pairing search. In the shared connection line generation step S7, the shared connection line generation unit 157 generates a single shared connection line L3 by connecting the section connection lines L21. Specifically, the shared connection line generation unit 157 first detects a shared point where a projection line obtained by projecting the target connection line L2 in the vertical direction onto a horizontal plane intersects with another projection line obtained by projecting another connection line L2 in the vertical direction onto a horizontal plane. A connection line separated by a shared point is called a section connection line. Next, the section connection lines intersecting on the vertical projection plane are connected so as to trace the outside of the structure to generate a single shared connection line. When generating a shared connection line, it may be an actual intersection where two connection lines actually intersect, or a three-dimensional intersection where they do not actually intersect. In other words, the elevations at the shared points of the two connection lines may be the same or different.

[0056] Specifically, as shown in 501 of FIG. 5, two connection lines L2(a) of the skeleton line L1(a) (assumed to be straight lines) and two connection lines L2(b) of the skeleton line L1(b) (assumed to be straight lines) are divided at a common point P1, which is an intersection point, and decomposed into a plurality of section connection lines L21 (12 in the example shown in FIG. 5). Then, the shared connection line generating unit 157 invalidates the section connection line L21 that passes through the inside of the structure from the common point P1. Then, as shown in 502 of FIG. 5, the shared connection line generating unit 157 generates the shared connection line L3 by selecting and connecting the connection line L21 that does not pass through the inside of the structure from the common point P1. In this way, the shared connection line L3 is generated with one end of the connection line L2 as the starting point. As shown in 502 of FIG. 5, the shared connection line L3 is not generated inside the intersecting structure. In other words, the section connection line inside the structure is not searched for pairing. Furthermore, when generating the intersection, a connection line of the intersection model is generated for the adjustment section. The ends of the connection lines in the intersection model share the same points as the original connection line L2.

[0057] By repeating this process of connecting the section connection lines L21 while changing the target connection line L2, the continuous section connection line L21, including the end lines, will form a loop. Therefore, the target connection line L2-shared point P1-other connection lines L2··shared point P1 is treated as a single circular shared connection line L3. All structures will be included in some loop structure.

[0058] Furthermore, when the shared connection line generating unit 157 determines that the target connection line L2 intersects with another connection line L2, it determines whether the shared point P1 is a shared point P1 at an actual intersection where the two lines actually intersect, or a shared point P1 at a multi-level intersection where the two lines do not actually intersect. Whether or not the two lines actually intersect can be determined from the presence or absence of an intersection identifier or from elevation data, as described above. Information on whether or not the two lines actually intersect is necessary to determine whether or not to generate a model along the intersecting connection lines.

[0059] In the following, a 3D mesh model of a structure including a slope or ground surface is referred to as a "model". For example, an intersection model that defines the structure of an intersection. In a real intersection, an intersection model including a slope or ground surface is generated along the connecting connection line. Therefore, it is necessary to process so that a model is not generated between the shared points inside the intersection. For this reason, the section connecting lines outside the intersection are connected at a common point, recognized as a single connecting line, and the connecting lines between the shared points are invalidated. The connecting connection line is a connecting line used to generate a 3D mesh, and in the case of a real intersection, the section connecting lines are connected at a common point to form a single connecting line. Since the connecting connection line is a common point where two connecting lines intersect in real, if the elevations of the common points obtained by interpolation are different, they need to be adjusted to the same elevation. On the other hand, the shared connection line is a connecting line used when searching for pairing, and is a single connecting line connected at a common point that is an intersection point when projected vertically, not limited to a three-dimensional intersection or a real intersection. However, it is not necessary that the shared points actually have the same elevation.

[0060] 503 and 504 in Fig. 5 show an example of a connection line for generating a model. 503 is a connection line L3 when two skeleton lines L1(a) and L1(b) shown in 501 intersect with each other in substance. In the case of an actual intersection, a connecting connection line is formed by connecting a common point P1. As shown in the figure, the connecting connection line shown in 503 has the same configuration as the common connection line shown in 502. Then, the surface generating unit 161 generates a ground surface or a slope from the connecting connection line L3.

[0061] 504 in FIG. 5 indicates a connection line when the two skeleton lines L1(a) and L1(b) shown in 501 intersect at an intersection. When there is an intersection at an intersection, the connection lines do not actually intersect, and become normal connection lines. Therefore, the two connection lines L3(a) of skeleton line L1(a) are drawn along skeleton line L1(a). The same is true for the two connection lines L3(b) of skeleton line L1(b). Then, the surface generating unit 161 generates a ground surface, a slope, or the like outside the normal connection lines L3(a) and L3(b).

[0062] Generally, a corner cut is provided at a real intersection of a road, and a square is provided at a real intersection of a waterway. Therefore, when generating a connection line L2 at a real intersection of a road or a waterway in the connection line generating step S6, the connection line generating unit 156 determines an intersection area based on the position information of the intersection point of the two skeleton lines L1 and the information of the width of the structure specified by the shape data. Then, the connection line generating unit 156 specifies the section connection line L21 included in the intersection area. Then, the connection line generating unit 156 further generates a connection line L4 of the intersection model (corner cut or square) as shown in FIG. 6 based on the shape data of the set intersection model. Then, the connection line generating unit 156 connects the connection line L4 of the generated intersection model to the connection line L2 to form a new connection line L3.

[0063] For example, when the actual intersection is a road intersection (four-way intersection), the connection line generating unit 156 generates a corner cutting connection line L2 that connects a pair of section connection lines L21 that sandwich a common point P1 in the intersection area based on the shape data of the corner cutting. Then, the connection line generating unit 156 connects the generated corner cutting connection line L2 to the already generated road connection line L2 to form one connection line L2. On the other hand, when the actual intersection is a waterway intersection, the connection line L2 that becomes the outline of the box is generated based on the position information of the intersection of the skeleton line L1 and the information of the width of the box specified by the shape data so that the center of the connection line L2 coincides with the intersection of the skeleton line L1 and a horizontal ground surface is formed around the box. Note that when the intersection model is a box, even in the case of an actual intersection, the elevations of the waterways may differ at the intersection. This is because even if the elevations of the various channels are different, the water flowing through them joins together at a manhole (the elevations do not have to be the same).

[0064] (8. Pairing step) After the elevation values ​​are assigned to the section between the two points to which the elevation data is linked and the connecting lines outside the section, the process proceeds to a pairing step S8. In the pairing step S8, the pairing unit 158 ​​first executes a pairing search. The pairing search is to search for a connecting line outside the shared connecting line L3 (in a direction perpendicular to the extension direction of the line) and to set the section where pairing is established as a paired connecting line. It can be said that the pairing search is to search for a connecting line located at a position that is likely to be paired as a combination of the ground surface or the slope. The pairing search is performed for all normal connecting lines and shared connecting lines. Note that there are two types of connecting lines for which the pairing search is performed: a normal (single) connecting line that does not intersect, and a shared connecting line (both when there is a multilevel intersection and when there is a real intersection).

[0065] The pairing search is performed at least by using the two-dimensional inscribed circle method, the three-dimensional inscribed sphere method, and the three-dimensional skewered ball method for a plurality of nodes P2. The nodes P2 are points that form the shared connection line L3. The intervals between the nodes P2 used in the pairing search are arbitrarily and discretely selected within a range of several tens of centimeters to several meters. The distance between the nodes P2 is approximated by a straight line. When performing the pairing search using two or more of the above three methods, for example, a method is given in which the section where the pair information (master and slave) described later is switched is roughly extracted using the inscribed circle method, and then only that section is examined again in detail using the skewered ball method.

[0066] In the two-dimensional inscribed circle method, first, three-dimensional vector information is converted into vector information on a two-dimensional plane by projecting it vertically onto a horizontal plane. Then, as shown in FIG. 7, a circle is generated on the two-dimensional plane that is tangent to the target non-intersecting normal connection line A (or shared connection line A) at one node P2 on the target connecting connection line A, and the circle is enlarged so that the tangent point does not move. Then, when the circle has a tangent point with the normal connection line B (or shared connection line B) or the normal connection line C (or shared connection line C) in addition to the original tangent point, pairing of the target connection line A with the other connection line B or C is established. Note that, normally, the number of tangent points that the circle has with each connection line by performing pairing is two, but there are also cases where the number of tangent points is three or more.

[0067] In the three-dimensional inscribed sphere method, first, in a three-dimensional space based on three-dimensional vector information, a sphere is generated that is in contact with the target connection line L3 at one node P2 on the target connection line L3, and the sphere is enlarged so that the contact point does not move. In the case of the three-dimensional inscribed sphere method, the sphere is generated at each node P2 in, for example, three directions, so that at least three paired contact points are generated. Which of these contact points is to be selected may be determined by judging the master-slave relationship (global order) and height relationship with the paired connection line.

[0068] In order to determine whether the direction of the inscribed sphere is a ground line or a slope line, pairing information must be obtained. However, strictly speaking, there are three directions in which the inscribed sphere is generated: the upslope line direction, the ground surface line direction, and the downslope line direction. In the case of an inscribed circle, it is paired with the connecting line with the shortest horizontal distance, but in the case of an inscribed sphere, it is paired with the connecting line with the shortest three-dimensional linear distance. However, unlike the case of an inscribed circle, in the case of an inscribed sphere, the direction of generation must be specified as one of the directions in the vertical plane relative to the connecting line. There are three such directions: the upslope direction, the ground surface direction, and the downslope direction. When a pairing search is performed in these three directions, the combination with the shortest linear distance is considered. For example, if it is an upslope line, if the point with which the other is paired is the master, the self becomes a slave, and the search in the upslope line direction is not adopted. Similarly, if the elevation of the other's internal contact point is lower than the self point, the search in the upslope line direction is not adopted. In that case, the pairing with the next shortest straight-line distance is considered. For example, if the pairing partner is a slave, the device itself is the master, and the search for the ground line direction is not adopted. On the other hand, if the partner is a slave, pairing is established. In this way, among the three directions, the direction being searched for pairing is judged in order of closest straight-line distance to see if it matches the combination of pairing information. If the combination of pairing information does not match, the next closest pairing is judged in the same way until a pairing is established. If no pairing is established until the end, it is determined that there is no pairing partner and the search ends.

[0069] Of these pairing methods, the two-dimensional inscribed circle method and the three-dimensional inscribed sphere method require relatively low computational costs for searches and are suitable for roughly creating pair connection lines. On the other hand, the two-dimensional inscribed circle method and the three-dimensional inscribed sphere method may not be able to accurately search for pair connection lines at or near points where pair connection lines (hereafter referred to as pair connection lines) switch. In contrast, the kushi-dango method requires high computational costs for searches, but can accurately search for pair connection lines.

[0070] (Skewered dumpling method) The Kushi-dango method is a pairing method for finding a pair of a first connection line and a second connection line that meets the condition that the ground surface or slope generated from the first connection line intersects with the ground surface or slope generated from the second connection line. The Kushi-dango method is a method for accurately pairing connection lines arranged three-dimensionally. The Kushi-dango method is also called the three-dimensional Kushi-dango method. An overview of the Kushi-dango method is given below.

[0071] First, the first connection line and its nodes are input as input. Next, as shown in Fig. 8, division points O1, O2...On are generated between adjacent nodes P1 and P2 at intervals of Δd1. The length of Δd1 is arbitrary. Fig. 8 is a plan view of the connection line between nodes P1 and P2 as seen from above. The coordinate symbols shown in the figure indicate that the horizontal plane is represented by the XY directions, and the vertical direction is represented by the Z axis. Note that the direction opposite to gravity (upward) is the positive direction of the Z axis.

[0072] Next, normal lines or ground plane lines are drawn from the nodes P1 and P2 and the division points O1 and O2···On. An example of drawing normal lines will be described below. FIG. 9 is a diagram showing normal lines from the nodes P1 and P2 and the division points O1 and O2···On as viewed from above. Hereinafter, the division points O1 and O2···On are also collectively referred to as division points On. First, normal lines are drawn from the nodes P1 and P2. When the angle between the connection lines at the node is 180 degrees or less, normal lines are generated at a predetermined inclination angle in a vertical plane perpendicular to the two connection lines that form the angle. In FIG. 9, the normal line vector from the node P1 is indicated as v1, and the normal line vector from the node P2 is indicated as v2. Then, intermediate points P are generated at intervals of Δd2 for the vectors v1 and v2. The length of Δd2 is arbitrary. The intermediate points P are P11, P12, . . . , P1m, etc. as shown in Fig. 9. All of these intermediate points are collectively referred to as intermediate point Pm.

[0073] Next, normal line vectors vO1, vO2, . . ., vOn are drawn from division points O1, O2, . . ., On to interpolate vector v1 and vector v2. Then, intermediate points O are generated for each vector at intervals of Δd2. The length of Δd2 is arbitrary. The intermediate points O are O11, O12, . . ., O1m, etc., as shown in Figure 9. Hereinafter, all of these intermediate points are collectively referred to as intermediate points Onm.

[0074] Fig. 10 is a diagram showing vectors v1, v2, and vectors vO1 to vOn viewed from the side (horizontal direction). As shown in Fig. 10, the inclination angle of vector v1 from node P1 and vector v2 from node P2 are different, so the inclination angle of linearly interpolated vector vO differs slightly.

[0075] Next, as shown in Figure 11, spheres with increasing radius are generated with each of the intermediate points Onm as the center. Then, another connection line that touches the generated spheres from each intermediate point Onm is searched for.

[0076] Specifically, the point of contact between a sphere with gradually increasing radius and another connecting line that first comes into contact with is defined as the contact point Q. Then, from among the multiple line segments OQ connecting the intermediate point Onm and the contact point Q, a line segment OQ (pairing line) that is approximately parallel to the normal line vector or ground surface line vector generated from the other connecting line is extracted. Then, the other connecting line that provides multiple pairing line candidates that are approximately parallel to the same normal line or ground surface line is found. With this method, the intersection line where the normal lines and ground surface lines between structures intersect can be found with high accuracy.

[0077] As described above, when the angle between the connection lines at a node is 180 degrees or less, a normal line or ground line is generated in a vertical plane perpendicular to the two connection lines that form that angle (PV line). Then, a pairing search is performed for each PV line. Thus, the above node has two pieces of pair information. On the other hand, when the angle between the connection lines is greater than 180 degrees, the connection lines are discretized at a predetermined angle from the node outward, and a normal line or ground line is generated for each angle (PV line). Then, a pairing search is performed for each PV line. Thus, a node that is open more than 180 degrees has two or more pieces of pair information.

[0078] By the above method, a pairing line (line segment OQ in FIG. 11) showing that the slope line and ground surface line between the structures are paired by the division point On, the midpoint Onm, and the contact point Q, and an intersection line connecting the intersection point where the slope line and the ground surface line intersect are obtained. An example of the pairing line and intersection line obtained in this way is shown in FIG. 12. FIG. 12 shows a pairing line and intersection line between a slope generated from one connection line and a ground surface generated from another connection line. Note that multiple pairs are obtained for each combination of a downslope and a ground surface, an upslope and a ground surface, a downslope and a downslope, an upslope and an upslope, and an upslope and a downslope, and since the combination is identified based on the global order and the relationship of the elevation position, the final pair is determined.

[0079] The above-mentioned skewered dumpling method may be executed by the earth surface data generation device 1. For example, the skewered dumpling method may be executed by having the processor of the control unit 15 read and execute a skewered dumpling method program stored in the storage unit 14. In addition, the earth surface data generation device 1 may visualize the search results as shown in FIG. 12 and output the image to the outside via the output unit 13.

[0080] As mentioned above, the Kushi-dango method requires a long processing time, which is a disadvantage in that the calculation cost is high. Therefore, pairing may be usually performed using the 2D inscribed circle method or the 3D inscribed sphere method. The Kushi-dango method may be used only when accurate pairing is required. After pairing is performed using the inscribed circle method or the inscribed sphere method, a slope or ground surface may be generated from each pair connection line, and when the slope and ground surface intersect, the Kushi-dango method may be used to consider the position and direction of the switching line that switches the slope and ground surface.

[0081] After performing the pairing search, the pairing unit 158 ​​sets the sections where pairing is established in each of the multiple shared connection lines L3 as paired connection lines. For example, in the example shown in Fig. 7, as a result of performing pairing search for a certain connection line A, when a section from one node to an adjacent node is considered as one section, one or more sections included in the connection line A are paired with a section connection line BA included in the connection line B, and one or more other sections are paired with a section connection line CA included in the connection line C, the pairing unit 158 ​​removes the section connection line AB and the section connection line BA including the certain section, and sets them as paired connection lines. Then, the pairing unit 158 ​​removes the section connection line AC and the section connection line CA including the other section, and sets them as other paired connection lines.

[0082] When performing pairing search, a self-intersecting portion may be found in the shared connection line L3. The self-intersecting portion refers to a state in which, when a circle or a sphere is generated from a node on a shared connection line L3 that is in contact with the shared connection line L3 and the circle or the sphere is enlarged so that the junction does not move, the junction that the circle or the sphere first has, apart from the original junction, is on itself (a shared connection line L3). The self-intersecting portion occurs, for example, when the shared connection line L3 has a closed shape. A closed shape refers to a case in which the angle that the two connection lines connected at the node P2 make toward the outside of the structure is smaller than 180 degrees. Conversely, an open shape refers to a case in which the angle that the two connection lines connected at the node P2 make toward the outside of the structure is 180 degrees or more. In such a case, the pairing unit 158 ​​pairs with itself.

[0083] Since there are no connection lines further outward from the outside of the drawing, the search range may be limited to a length of about 30m to 200m in order to avoid paying unnecessary calculation costs in the pairing search. If no pairing partner is found, the pair information may be set to "no pair information." If there is no pair information, a slope line or ground surface is generated on a rule basis. Note that the connection lines between shared points at an intersection also do not have pair information, but since the connection lines in this part can be recognized as connection lines between shared points, the ground surface or slope may be determined by referring to the pair information of adjacent connection lines.

[0084] In the case of a three-dimensional intersection, since each structure exists independently, it is necessary to generate a model independently of each other. The common points P1 of each connection line L2(a) generated on both the left and right sides of one skeleton line L1(a) that forms a three-dimensional intersection and each connection line L2(b) generated on both the left and right sides of the other skeleton line L1(b) are not connected to each other, but are independent of each other. As a result, the connection line L2(a) and the connection line L2(b) generate a slope or ground surface from the connection line L21 between the common points in each structure. Specifically, if it is determined in the above-mentioned determination step S5 that the common point P1 is in a three-dimensional intersection, the slope or ground surface is generated from the section connection line between the common points in the surface generation step S11 described later. However, the section connection line between the common points does not have pair information because pairing search is not performed. Therefore, the slope or ground surface is generated by referring to the pair information of the connection line adjacent to the section connection line. Details are as follows.

[0085] In the case of a three-dimensional intersection, since the angle is likely to be closed at the shared point, the connection line adjacent to the section connection line is likely to obtain pair information with the connection line itself. In other words, there is a high possibility that a section will occur that has no pair information other than its own connection line. For this reason, a normal line or ground surface line is generated for the section connection line by referring to the pair information of the two section connection lines adjacent to the section connection line. Note that even at the point of actual intersection, since the angle is closed at the shared point, there is a high possibility that it will be a self-intersection. In other words, there are many cases where a section connection line does not have pair information other than its own connection line. In this case, the normal line or ground surface line is generated in the same manner as above.

[0086] Although a pair connection line is generated by the pairing search, the pair connection line may not be divided at an appropriate position depending on the method of the pairing search. For this reason, in the pairing step S8, the pairing unit 158 ​​may be configured to receive an instruction to change the division position. The instruction to change is given by the user using the operation unit 12. Even if a pairing search is performed, a partner to be paired may not be found depending on the position or shape of the connection line L2.

[0087] (9. Pair information setting step) After the pair connection line is generated, the process proceeds to a pair information setting step S9 as shown in FIG. 3. In the pair information setting step S9, the pair information setting unit 159 sets pair information for each section included in the pair connection line based on the overall global ranking. The pair information is information indicating a master-slave relationship between the sections, and there are two types of pair information: master (main) and slave (slave). The pair information setting unit 159 sets the pair information by referring to the global ranking set for each section included in the pair connection line. Specifically, the pair information setting unit 159 sets the pair information of a section with a relatively high global ranking among the sections included in the pair connection line to the master. On the other hand, the pair information setting unit 159 sets the pair information of a section with a relatively low global ranking among the sections to the slave. Furthermore, when the global rankings of the sections are the same, the pair information setting unit 159 sets the same pair information (master or slave) for both sections.

[0088] Furthermore, the pair information setting unit 159 sets different colors for the section where the master pair information is set (where a slope occurs) and the section where the slave pair information is set (where a ground surface line occurs). As a result, in the data output step S13 described later, the section where the slope occurs and the section where the ground surface line occurs are displayed in different colors. Furthermore, the pair information setting unit 159 sets information indicating the direction in which the ground surface line or the slope line occurs at each node. As a result, in the data output step S13 described later, an arrow or the like indicating the direction in which the ground surface line or the slope line occurs is displayed. Furthermore, the pair information setting unit 159 sets information to generate a switching line at a node where the ground surface and the slope are replaced. As a result, in the data output step S13 described later, the switching line is displayed in a color different from that of the ground surface line or the slope line.

[0089] When the intersection of two skeleton lines L1 is a real intersection point, each connection line L2 generated based on these skeleton lines L1 also intersects in the same way as the skeleton lines L1. In this case, the elevations at the common point P1, which is the intersection point of each connection line L2 with the other, are set to be the same, and each connection line L2 belongs to the same common connection line L3. Each skeleton line L1 is assigned a global order. And the connection lines L2 generated based on each skeleton line L1 inherit the global order of the skeleton line L1.

[0090] (10. Switching line generation step) After the pair information is set, the process proceeds to a switching line generating step S10. In the switching line generating step S10, the switching line generating unit 160 searches for a point where a ground surface line or a normal line generated from one of the pair connection lines switches from one to the other, and generates a switching line L5 as shown in FIG. 13. Specifically, the switching line generating unit 160 searches for a point where a ground surface line or a normal line switches from one to the other and a direction in which the other line extends. When generating the switching line L5, the direction of the switching line L5 is also specified.

[0091] (11. Surface generation step) After generating the paired connection lines, the process proceeds to a surface generating step S11 as shown in FIG. 3. In the surface generating step S11, the surface generating unit 161 generates a slope or a ground surface from each paired connection line based on the pair information of each section included in the paired connection line. The slope (line) or the ground surface (line) is generated from a normal connection line (not having a common point) and a linking connection line. As described above, the linking connection line is a connection line obtained by connecting the common points where the connection lines of the structures actually intersect. The linking connection line includes a section connection line that does not have pair information, but the slope or the ground surface is generated by referring to the pair information of the connection line adjacent to the section connection line. When the connection lines of the structures intersect as an entity and mesh data (hereinafter also simply referred to as "mesh") of the intersection is generated, the slope or the ground surface is generated from the linking connection line obtained by connecting the common points. When the connection lines of the structures intersect as an entity and mesh data of the intersection (hereinafter also simply referred to as "mesh") is generated, the slope or the ground surface is generated from the linking connection line obtained by connecting the common points. When the connection lines of the structures intersect with each other in a multi-level intersection and mesh data of the intersection is not generated, the slope or the ground surface is generated from each of the intersecting connection lines.

[0092] Specifically, the surface generating unit 161 first sets a plurality of nodes P2 on the pair connection line. Alternatively, the nodes P2 may be nodes already set on the shared connection line. Then, as shown in FIG. 7, the surface generating unit 161 generates a ground surface line L6 from the nodes P2 set on the pair connection line, or a normal line L6 having a predetermined inclination angle (defined by the shape data) from the horizontal plane. The surface generating unit 161 refers to the pair information set for each section of the pair connection line, generates a normal line L6 from the connection line L2 for which the master pair information is set, and generates a ground surface line L6 from the connection line L2 for which the slave pair information is set.

[0093] In the case of a ground surface line L6 where the angle between the connection lines on both sides of the starting point (node) is 180 degrees or less, as described above, a normal line or a ground surface line is generated in a vertical plane perpendicular to the two connection lines that form an angle. Then, a ground surface or a slope is generated for each connection line. On the other hand, when the angle between the connection lines is greater than 180 degrees, the connection lines are discretized at a predetermined angle from the node toward the outside, and a normal line or a ground surface line is generated for each angle. Then, a ground surface or a slope is generated for each connection line. Specifically, the surface generating unit 161 generates a plane (mesh) that becomes a ground surface or a slope between the adjacent ground surface lines L6, the slope line L6, or the switching line L5 generated in the switching line generating step. Note that, when the pair information of the low-lying structure is the master and the pair information of the high-lying structure is the slave, the surface generating unit 161 generates an upslope from the connection line L2 of the low-lying structure.

[0094] If the angle between the connection lines on both sides of the starting point (node) exceeds 180 degrees, the angle is discretized (divided) at a specified angle, and a ground surface line or normal line of a specified length is generated radially. When generating a ground surface, the tip of the ground surface line of a specified length is connected to form a ground edge line, and the range surrounded by the connection line, adjacent ground surface lines, and ground edge lines is the ground surface. When generating a slope, a normal line with a discretized angle from the starting point is generated to the base ground with a specified downward gradient (inclination angle). Then, the surface consisting of the starting point and the two points where the two adjacent normal lines intersect with the base ground is the slope. The range in which the ground surface line or normal line is generated radially is the range of the angle formed by two vertical planes having the orthogonal components of the line segment obtained when the connection line is projected vertically onto a horizontal plane through the node, with respect to each connection line, toward the outside of the connection line. The base ground is a ground surface with an elevation lower than the elevation of the lowest part of all structures. Specifically, for example, the lowest elevation value of the node elevations of all the connection lines can be obtained, and the elevation value can be lowered by any height from that elevation value to become the elevation of the base ground. This allows the elevation of the base ground to be set in the program. The base ground is the reference surface for determining the elevation up to which the downward slope is generated in 3D model generation.

[0095] All structures belong to one of the loops (multiple) that are made up of a series of section connection lines. The loops may be normal connection lines or linked connection lines, and may include end lines in some cases. In the surface generation step S11, the connection lines and end lines of one or more structures are expressed as loops, and a surface is generated for each loop. Next, a Boolean operation is performed on the surface generated for each loop using the plane method within the loop to generate a mesh that is connected with meshes of only the ground surface of the structures included in the same loop. At this time, meshes below the ground surface are removed. This process is performed for all structures included in the same loop. Then, a Boolean operation is performed again on all the ground surface meshes generated for each loop, and meshes that are connected with meshes of only the ground surface of all structures are generated by removing meshes below the ground surface.

[0096] When the same pair information is set for each section of the pair connection line, the surface generating unit 161 generates the same type of surface (ground surface or slope) from each section of the pair connection line. When the pair connection lines have the same order, the model (ground surface or slope) generated at the point where the order of proximity is changed is adopted. Also, in the above pairing step S8, when there is a connection line L2 for which a partner to be paired cannot be found, the surface generating unit 161 generates a surface from the connection line L2 according to a predetermined rule (for example, generating a slope from a connection line L2 for which a partner cannot be found).

[0097] When the connection line of the intersection model has been generated, the surface generating unit 161 also generates a ground surface or a slope from the connection line L4 of the intersection model as shown in FIG.

[0098] The surface generating unit 161 may generate a surface from the section connecting line L21 that is the same type as a surface extending from another section connecting line L21 that connects to the section connecting line L21, or may generate a different surface. For example, when generating a slope and a ground surface adjacent to each other, the surface generating unit 161 may generate a slope that becomes gentler as it approaches the ground surface, so that the ground surface and the slope are smoothly connected.

[0099] The surface generating unit 161 also generates a ground surface or a slope from the end line. The surface generating unit 161 basically generates a downward slope. However, depending on the surface extending from the left and right connecting lines L2 of the skeleton line L1, the surface generating unit 161 generates a surface that can be continuously connected to the ground surface line or the slope line extending from the intersection of the end line and the connecting line L2. When the surfaces extending from the left and right connecting lines L2 are the same (symmetrical), the surface generating unit 161 generates a surface of the same type as the surface extending from the connecting line L2 from the end line. When both the surfaces extending from the left and right connecting lines L2 are slopes and each slope includes a step, the surface generating unit 161 generates a slope including a step from the end line. In addition, when the surfaces extending from the left and right connecting lines L2 are slopes with different inclinations, the surface generating unit 161 generates a slope whose gradient gradually decreases from a steep slope to a gentle slope. Furthermore, when the surface extending from the right connection line L2 is either the ground surface or a slope, and the surface extending from the left connection line L2 is the other, the surface generating unit 161 generates a slope whose gradient gradually decreases from the slope to the ground surface. Furthermore, when the surfaces extending from the left and right connection lines L2 are slopes and one of the slopes includes a berm, the surface generating unit 161 generates a slope whose width gradually narrows from the slope including the berm to the slope not including the berm. The loop formed by the connection lines and the end lines is formed by one or more structures.

[0100] If the ground surface or slope is simply generated from each section connection line L21, the surface may intersect with another surface, and a part of one surface may overlap a part of the other surface in the vertical direction. Therefore, in the ground surface data generation method according to this embodiment, in the surface generation step S11, the surface generation unit 161 deletes the other surfaces from among the overlapping surfaces, leaving only the top surface (ground surface). The surface generation unit 161 performs this process using Boolean operations (plane method). As a result, the three-dimensional model consisting of the structure, the ground surface, and the slope is composed only of meshes representing the ground surface. Note that if a part of one surface overlaps a part of the other surface in the vertical direction, in the surface generation step S11, the surface generation unit 161 reconstructs the top surface.

[0101] In the surface generating step S11, the surface generating unit 161 executes the above-described processing, thereby generating a three-dimensional model such as that shown in FIG.

[0102] (12. Warning information extraction step) After the three-dimensional model is generated, the process proceeds to warning information extraction step S12. In warning information extraction step S12, warning information extraction unit 162 determines whether or not the generated three-dimensional model has any of the following problems. - The downward slope extending from a higher structure crosses the connection line L2 of the lower structure, or the upward slope extending from a lower structure passes under the connection line L2 of the higher structure. - The slope of the slope exceeds the specified tolerance (value specified in the design standards). - The gradient of the waterway is above or below the specified tolerance range. - The gradient of the driving surface (paved surface or approach road to the field) exceeds the specified tolerance. - The difference in elevation between two structures on either side of the slope is less than the specified tolerance (value specified in the design standards).

[0103] The determination as to whether or not the downward slope extending from the high structure crosses the connection line L2 of the low structure is performed as follows. Note that this determination is performed for the connection line L2 that the slope crosses first, and is not performed for the connection line L2 that the slope crosses second. Specifically, the warning information extraction unit 162 refers to a cross section of the structure and the slope cut by a plane perpendicular to the skeleton line L1, and determines whether or not the slope line, which is the cross section of the slope, passes over a point that is the cross section of the connection line L2 of the low structure. If it is determined that the slope line passes over the point, the downward slope extending from the high structure crosses the connection line L2 of the low structure. In this case, the warning information extraction unit 162 assigns warning information to the slope that passes over the point. Note that in the above acquisition step S1, if the section that becomes an underpass on the skeleton line L1 is drawn with a broken line, processing may be performed so that it is not determined that there is a problem even if the downward slope crosses the broken line.

[0104] When generating a slope connecting one section and the other section included in a pair of connection lines, a slope with a gradient larger than the allowable value may be generated. Whether or not the slope inclination exceeds the allowable value is determined as follows. First, as shown in FIG. 15, a point sequence vector V extending from a point on the connection line L2 of a high-altitude structure (road) to a point on the connection line L2 of a low-altitude structure (waterway) is generated, and the angle θ between the point sequence vector V and the horizontal plane H is extracted. Then, it is determined whether or not the extracted angle θ exceeds the allowable value. Here, if the angle θ exceeds the allowable value, the slope inclination exceeds the allowable value. In this case, the warning information extraction unit 162 assigns warning information to the slope.

[0105] To determine whether the gradient of the waterway exceeds or falls below the range of the allowable value, the angle between the waterway's skeleton line L1 (directed polyline) and the horizontal plane is extracted. Then, it is determined whether the extracted angle exceeds or falls below the range of the allowable value. If the angle exceeds the allowable value, the gradient of the waterway exceeds the allowable value. In this case, the warning information extraction unit 162 assigns warning information to the waterway. Similarly, to determine whether the gradient of the travel road surface exceeds a predetermined allowable value, the angle between the travel road's skeleton line L1 (directed polyline) and the horizontal plane is extracted. Then, it is determined whether the extracted angle exceeds the range of the allowable value. The same applies to the warning information.

[0106] The determination of whether the elevation difference between two structures sandwiching a slope is less than the allowable value is performed as follows. First, the connection line L2 of one structure that pairs with the connection line L2 of the other structure is searched for using any one of the two-dimensional inscribed circle method, the three-dimensional inscribed sphere method, and the three-dimensional skewer-and-dumpling method used in the pairing step S8. Then, the elevation values ​​of the pair of connection lines L2 that form a pair are calculated. Then, the elevation difference, which is the difference between the calculated elevation values, is calculated, and the elevation difference is compared with the allowable value. Here, if the elevation difference is smaller than the allowable value, it means that the elevation difference between the structures is insufficient. In this case, the warning information extraction unit 162 assigns warning information to a point or section on the connection line L2.

[0107] When a waterway is installed between the road and the field, the warning information extraction unit 162 cannot directly compare the elevation difference between the road and the field scene. In such a case, a node on the road connection line and a node on the waterway connection line corresponding to that node are obtained, and a node on the waterway connection line that is paired with that node on the opposite side is extracted. Furthermore, a node on the field connection line corresponding to this node is obtained. The node on the field connection line can access field elevation data. This makes it possible to obtain elevation difference information between the node on the road connection line and the field. This information is compared with the allowable elevation difference value, and if it is smaller, the warning information extraction unit 162 assigns warning information to a point or section on the connection line L2.

[0108] When a waterway is included in the generated 3D model, the warning information extraction unit 162 according to this embodiment adds an arrow indicating the water flow direction to the waterway as warning information. The warning information extraction unit 162 determines the water flow direction based on the elevation values ​​of both ends of the waterway skeleton line L1. The warning information extraction unit 162 adds an arrow to all generated waterways. This allows the user to confirm the water flow direction.

[0109] When a structure or the like to which warning information has been assigned is present, the warning information extraction unit 162 performs processing to notify the user of the warning information. Specifically, the warning information extraction unit 162 colors the structure, surface, or line to which warning information has been assigned in a warning color that is different from normal. When the structure in which a problem exists is a waterway, the warning information extraction unit 162 colors the arrow indicating the water flow or the waterway in a warning color. This enables the user to check whether there is a problem with the gradient of the waterway.

[0110] Even if the warning information extraction unit 162 judges that a problem exists, there are cases where it does not actually become a problem. For example, in the case of a multi-level intersection of roads or waterways, a downward slope extending from an upper road or waterway may cross a connecting line L2 of the road or waterway that passes underneath. Also, in terraced rice fields in steep mountainous areas, there may be places where the difference between the road surface and the rice field surface is reversed (the elevation difference becomes negative). Even in such cases, the warning information extraction unit 162 will not stop the execution of other processes even if it colors the structure, surface, or line with the problem in a warning color different from normal (it only notifies the user).

[0111] When the warning information extraction unit 162 according to the present embodiment determines that a downward slope extending from a high-altitude structure crosses the connection line L2 of a low-altitude structure, it colors the downward slope in a warning color and generates a reference line L7. The reference line L7 is a line that serves as a guide when moving the position of the skeleton line L1 in a modification step S14 described later. Note that the movement of the skeleton line L1 using the reference line L7 is premised on the assumption that no change is made to the elevation value and slope shape of the skeleton line L1 (only horizontal movement). Specifically, the warning information extraction unit 162 first sets a plurality of vertical planes with intervals between them that coincide with the direction in which the slope line is generated with respect to the connection line L2. Then, on each vertical plane, as shown in FIG. 16, it obtains point A that is directly above the connection line L2 and on the slope, and point B that is directly below point A and on the connection line L2. Next, it obtains point C that is on the extension line of the slope and coincides with the elevation of point B. Furthermore, it obtains the horizontal distance d1 between point B and point C. Also, find point D of intersection between a vertical plane passing through points A, B, and C and the skeleton line L1 of the high structure. Point E is the point located a horizontal distance d1 from point D in a direction away from the low structure. Point G is the point located a horizontal distance d1 from point F on the skeleton line L1 of the low structure in a direction away from the high structure. The straight lines connecting points E on each vertical plane and the straight line connecting points G on each vertical plane are each designated as reference lines L7.

[0112] If point D (skeleton line L1 of the high-altitude structure) is moved to the reference line L7 formed by connecting point E, the regenerated slope will not cross the connection line L2 of the low-altitude structure. Conversely, if point F (skeleton line L1 of the low-altitude structure) is moved to the reference line L7 formed by connecting point G, the slope will also not cross the connection line L2 of the low-altitude structure. Conventionally, when a downward slope extending from a high-altitude structure crosses the connection line L2 of a low-altitude structure, trial and error was required to move the skeleton line L1 to an appropriate position. However, the warning information extraction unit 162 according to this embodiment generates the reference line L7. Therefore, in a modification step S14 described later, the user can solve the problem of the three-dimensional model simply by moving the skeleton line L1 so that it coincides with the reference line L7.

[0113] (13. Data output step) After determining whether or not there is a problem, the process proceeds to data output step S13. In data output step S13, the data output processing unit 163 causes the output unit 13 to output the 3D CAD data. If the output unit 13 is a terminal to which a cable leading to a monitor is connected, or the monitor itself, this step causes the 3D model to be displayed on the monitor. If the output unit 13 is a communication unit that communicates with other devices, or a drive that writes 3D model data to media, this step causes the 3D CAD data to be provided to other devices, etc. The user can refer to the output data and make corrections, if necessary, in the modification step described below.

[0114] When the process for notifying the user of the warning information is performed in the warning information extraction step S12, the data output processing unit 163 displays the structure, surface, or line in which the problem exists in the 3D model displayed on the monitor in a warning color different from normal. This allows the user to easily grasp the position of the structure, surface, or line having the warning information. Furthermore, the user can easily consider the cause of the problem from the position or shape of the structure, surface, or line displayed in the warning color. Furthermore, when the data output processing unit 163 displays a 3D model of a waterway, it displays an arrow indicating the direction of the water flow on or near the waterway together with the waterway. This allows the user to easily check whether the water is flowing as intended.

[0115] In addition, in response to an output request from a user, in the data output step S13, the data output processing unit 163 converts the 3D CAD data of the 3D model in which the skeleton line L1 and the elevation value have been corrected into 2D CAD data and outputs it. When the skeleton line L1 is corrected, the data output processing unit 163 outputs 2D CAD data in which the plane coordinate value of the skeleton line L1 has been corrected. On the other hand, when the elevation value is corrected or added, the data output processing unit 163 outputs 2D CAD data in which the numbers written near the elevation identifier have been corrected or a new elevation identifier and number have been added. Note that the 2D CAD data cannot hold shape data. Therefore, when outputting the 2D CAD data, the shape data set for each skeleton line L1 is output together with the 2D CAD data. The 3D model can be reproduced by reading this 2D CAD data and shape data into the earth surface data generating device. Note that the data output processing unit 163 may be configured to output the 3D CAD data of the 3D model in which the skeleton line L1 and the elevation value have been corrected without converting it into 2D CAD data (as 3D CAD data). In this case, the data output processing unit 163 may output only the skeleton line data (in this case, additional shape data is required to reproduce the three-dimensional model), or may output both the skeleton line and the shape data. Furthermore, the data output processing unit 163 may output shape data (shape parameters) including the skeleton line data, which is linked to the layer.

[0116] (14. Change Step) If the generated 3D model has a surface contrary to the user's intention (a slope surface is created in spite of the intention to make it a ground surface, or vice versa), or if a surface colored in a warning color is present and the user judges it necessary, the 3D model needs to be modified. Therefore, in the ground surface data generation process according to this embodiment, after the 3D model is generated and a modification operation by the user is accepted, the process proceeds to a modification step S14. In the modification step S14, the modification unit 164 performs processing according to the modification operation. Specific examples of modification operations include, for a skeleton line, adding and deleting points constituting the skeleton line, and changing the coordinates of the constituent points, for a field, adding and deleting points constituting a polygon, and changing the altitude. For a road, the shape parameters include width and gradient, and for the ground surface, the parameters include modification to the ground surface line, slope line, and switching line to be generated between structures.

[0117] When an operation to replace the pair information of the pair connection lines is received, the change unit 164 changes the slope or ground surface generated from each of the pair connection lines. Specifically, the change unit 164 changes the slope line extending from the connection line to a ground surface line, or changes the ground surface line extending from the connection line to a slope line. Note that the pair information may be changed from master to slave, or from slave to master. When the slope line / ground surface line or the pair information is changed, the process proceeds to the surface generation step again, and the surface generation unit 161 regenerates the three-dimensional model. At that time, the surface generation unit 161 regenerates the slope or ground surface from each of the pair connection lines based on the pair information, slope line, or ground surface line changed by the user. Note that in the change step S14, the change unit 164 may receive an operation to specify the section connection line L21 and a surface to be generated from the section connection line L21. In that case, the change unit 164 changes the surface already generated on the specified section connection line L21 to the specified surface. The change unit 164 may also receive an operation to change the overall global ranking. In that case, the global ranking is changed according to the received operation, and the changed global ranking is then reflected in the pair information. A switching line can also be set at the boundary where the ground surface line and the normal line switch, and the position of this switching line can also be changed.

[0118] On the other hand, when an operation to move the plane coordinates of the skeleton line L1 or an operation to add or change an elevation point is received, the modification unit 164 modifies at least one of the position, extension direction, and gradient of the skeleton line L1. Thereafter, the process moves again to the connection line generation step S6 and the surface generation step to regenerate the 3D model. At that time, it is determined whether or not the problem that existed before receiving the operation has been resolved, and if it is determined that it has been resolved, the surface to be generated is colored in a normal color.

[0119] Furthermore, if the shape of the structure is changed due to the modification of the skeleton line L1, the process returns to the pairing step S8, where the pairing unit 158 ​​performs pairing search again. If the combination of sections that become paired connection lines is changed as a result, the pairing unit 158 ​​resets the pair information within the changed paired connection lines.

[0120] [Action and Effect] Conventionally, when a user wants to generate a slope on a certain connection line L2 and generate a ground surface in a certain part, the user needs to change the model by dividing the sections one by one, which is time-consuming. However, the above-described ground surface data generating device, method, and program generate a ground surface or a slope from the section connection line L21 according to the program in accordance with pair information linked to each section that is the starting point for generating the surface. Therefore, according to the ground surface data generating device, method, and program, when designing a three-dimensional model of the ground surface including multiple structures by parametric modeling, it is possible to easily generate a three-dimensional model of the ground surface or the slope between structures.

[0121] Currently, 3D design is becoming mainstream in the civil engineering industry. Using a 3D model generated by 3D design, the completed image can be easily communicated to the other party. However, small and medium-sized enterprises still cannot prepare dedicated software for 3D design and computers with high processing power, and cannot secure enough designers to perform 3D design. The reasons for this include the fact that dedicated software and computers are very expensive, high skills and experience are required to master the dedicated software, and the fact that it takes a huge amount of time to draw, making it poorly cost-effective. However, by using the above-described earth surface data generation device, method, and program, it is possible to obtain elevation data from 2D CAD data in which numbers indicating the elevation are written together with elevation identifiers, and generate a 3D model. Therefore, designers can easily perform design using inexpensive 2D design software while generating a 3D model.

[0122] [Embodiment 2] Next, as the second embodiment, a method for generating mesh data for design and construction, a device for generating mesh data for design and construction, and a program for generating mesh data for design and construction will be described. Hereinafter, the "mesh data for design and construction" will also be simply referred to as "mesh data for construction". For convenience of explanation, the same reference numerals will be used for members having the same functions as those described in the first embodiment, and the explanations will not be repeated. The device 2 for generating mesh data for design and construction (hereinafter, the device 2 for generating) described here is used when implementing the method for generating mesh data for design and construction (hereinafter, the method for generating) according to the second embodiment. As shown in FIG. 17, the device 2 for generating includes a storage unit 24 and a control unit 25 in addition to the input unit 11, the operation unit 12, and the output unit 13 similar to those of the earth's surface data generating device 1 according to the first embodiment.

[0123] (Storage part) The storage unit 24 stores a generation program 241 for generating mesh data for design and construction (hereinafter, the generation program 241). The generation program 241 describes the flow of the generation process executed by the control unit 25. The storage unit 24 according to this embodiment is configured with a semiconductor memory or a hard disk. Note that when the generation program is not required (for example, when the control unit 25 performs all of the various calculations described below using logic circuits), the generating device 2 does not need to be provided with the storage unit 24.

[0124] (Control unit) The control unit 25 includes a control block including a second acquisition unit 152, an interpolation unit 153, a global ranking setting unit 154, a judgment unit 155, a connection line generation unit 156, a shared connection line generation unit 157, a pairing unit 158, a pair information setting unit 159, a switching line generation unit 160, a surface generation unit 161, a warning information extraction unit 162, and a change unit 164 similar to the control unit 15 of the earth surface data generation device 1 of embodiment 1, as well as an acquisition unit 251, a first generation unit 252, a second generation unit 254, a third generation unit 255, a fourth generation unit 256, a fifth generation unit 257, a sixth generation unit 258, a seventh generation unit 259, and an output processing unit 260.

[0125] The first generating unit 252 generates mesh data of the current structure and the planned structure in the leveling stage. The second generating unit 254 generates mesh data of the structure in the drainage channel construction stage. The third generating unit 255 generates mesh data of the structure in the levee construction stage. The fourth generating unit 256 generates mesh data of the structure in the road construction stage. The fifth generating unit 257 generates mesh data of the structure in the irrigation channel construction stage. The sixth generating unit 258 generates mesh data of the structure after completion. The seventh generating unit 259 generates mesh data of the land other than the current structure of the current construction site from the current topographical information. Note that the mesh data of the land other than the current structure of the current construction site may be generated by the first generating unit 252 instead of the seventh generating unit 259.

[0126] The control unit 25 is composed of a processor. The control unit 25 executes a generation processing method as shown in FIG. 18 according to the generation program 241 stored in the storage unit 24. The generation processing method includes an acquisition step S21, a generation step S22, and an output step S23. Each step in the generation processing corresponds to each step included in the generation method of mesh data for design and construction according to this embodiment. Note that the control unit 25 does not need to include all of the first generation unit 252, the second generation unit 254, the third generation unit 255, and the fourth generation unit 256, and may include one or more according to the 3D mesh of the construction stage to be generated.

[0127] (1. Acquisition step) In the first acquisition step S21, the acquisition unit 251 acquires skeleton line data of the current state structure on the construction site and shape data defining the shape of the current state structure, and skeleton line data of the planned (designed or completed) planned structure and shape data defining the shape of the planned structure. This acquisition unit 251 also has the function of the acquisition unit 151 according to the first embodiment. The current state structure is a structure that already exists. The acquisition unit 251 acquires elevation data, ground data, etc. of the current state structure. The "ground data" of the current state structure is, for example, data indicating the shape and elevation of the surface (base surface) of the base layer on which the cultivation layer is arranged, and the value of the survey data is acquired. The acquisition unit 251 may acquire data of land other than the current state structure (position data, elevation data, ground data, etc.). The land other than the current state structure is, for example, grassland, sandy land, forest, etc. Information on the current state structure and other land is called current state topographical information.

[0128] As described in the first embodiment, a skeleton line is a line that serves as a reference for a structure. Skeleton line data is data that defines a skeleton line, and includes position data, elevation data, ID, type, etc. Shape data is parameter data that defines the shape of a parametric model of a structure, and is specifically as described in the first embodiment.

[0129] A planned structure is a structure that is designed to be newly constructed. "The skeleton line data of the planned structure and the shape data that defines the shape of the planned structure" refers to the skeleton line data and shape data of roads, fields, ridges, waterways, and other structures that are planned to be newly constructed. The skeleton line data and shape data are as described above.

[0130] The acquisition unit 251 according to the present embodiment may acquire three-dimensional point cloud data, and generate skeleton line data, elevation data, and shape data of the current state structure from a plurality of coordinate values ​​(x, y, z) included in the three-dimensional point cloud data. If skeleton line and shape data of the current state structure exist, the data may be acquired. The three-dimensional point cloud data is survey data obtained based on photos taken by UAVs (Unmanned Aerial Vehicles), aircraft, artificial satellites, etc., of the ground surface, and reflected laser light from the ground surface collected by these. In this case, the acquisition unit 251 first reproduces a point cloud based on the acquired three-dimensional point cloud data in a three-dimensional space. Then, the acquisition unit 251 recognizes the current state structure from the reproduced point cloud, and draws the skeleton line L1 of the current state structure on a layer to which the corresponding layer name (current state, work type, and ID) is assigned. The acquisition unit 251 generates shape data of the current state structure and records it in the storage unit 24. Alternatively, if the current state structure is constructed using a parametric model, the acquisition unit 251 may acquire the skeleton line data and shape data thereof. The first generation unit 252 generates skeleton line data and shape data of the current state structure as necessary from the point cloud data acquired by the acquisition unit 251. Note that the recognition of the current state structure and the drawing of the skeleton line L1 may be performed by a user.

[0131] As described above, in the acquisition step S21, the acquisition unit 251 also acquires skeleton line data of the planned structure and shape data that defines the shape of the planned structure. Hereinafter, the "planned structure" is also simply referred to as a "structure." Specifically, the acquisition unit 251 acquires skeleton line data and a layer name (ID) of each structure stored as design data in the storage unit 24. The acquisition unit 251 also acquires shape data linked to the skeleton line data. Furthermore, the acquisition unit 251 associates the shape data with the ID.

[0132] For example, when the construction stage is a drainage channel construction stage, multiple excavation cross sections may be set following the construction stage. Specifically, for example, in the construction of a drainage channel, a temporary drainage channel is first constructed for drainage during construction work. This is called primary excavation. In order to perform this primary excavation, the second generation unit 254 generates a primary excavation mesh having position information for the primary excavation. The primary excavation mesh may include a small step. Based on this information, the ICT construction machine can perform excavation work on a part higher than the current topography. This primary excavation mesh is an uphill slope as seen from the drainage channel since it is mainly used for excavation. The excavation slope length may have a certain height higher than the surrounding current topography, the excavation slope length may be specified by a parameter, or a ground surface mesh between structures may be generated as in the first embodiment. The temporary drainage channel allows rainwater to be quickly drained during the construction period. Then, after the field preparation is completed, the ICT construction machine lays foundation materials such as gravel using the secondary excavation mesh generated by the second generation unit 254 in order to install a concrete flume, and installs the concrete flume. After that, the completed mesh is used to shape the surroundings of the waterway and the slopes. Although there are three steps in the above example, the construction cross section determined by the shape parameters may be increased as necessary.

[0133] FIG. 19 is a schematic diagram showing an example of shape data (shape parameters) of the primary excavation and secondary excavation of a drainage channel. In the drainage channel construction stage or the irrigation channel construction stage, the shape data includes basic parameters, slope parameters, berm parameters, and ICT construction parameters. The primary excavation parameters define the cross-sectional shape of the temporary drainage channel (earthen waterway) after the primary excavation. The secondary excavation parameters define the cross-sectional shape after the secondary excavation. The basic parameters include the width of the structure (concrete flume, etc.), the height of the structure, the width of the foundation concrete, the height of the foundation concrete, the height of the spread mortar, and the distance from the skeleton line to the left and right shoulders. The slope parameters include the gradient of the right slope and the gradient of the left slope. The berm parameters include the presence or absence of berms in the middle of the slope, and if there are berms, the number of berms installed, the installation height of each berm, and the width of each berm. The ICT construction parameters include the primary excavation parameters and the secondary excavation parameters. The primary excavation parameters include the height of the construction base from the skeleton line, the excavation width, the excavation slope length, the excavation gradient, and the excavation mesh length, as shown on the left side of Fig. 18. The secondary excavation parameters include the bed excavation height, bed excavation width, bed excavation gradient, and the excavation slope length, as shown on the right side of Fig. 18.

[0134] The data required for the construction stage of the land leveling stage are the mesh of the base surface layer and the mesh of the cultivated surface layer. The height of the mesh of the cultivated surface layer is the altitude of the field. The surface layer that is the thickness of the cultivated layer below the altitude of the field is the base surface layer. Therefore, it is possible to generate the mesh of the cultivated surface layer and the base surface layer by simply specifying the thickness of the cultivated layer. The shape data includes the thickness of the cultivated layer and the expected subsidence amount. The "expected subsidence amount" is the amount of subsidence that is expected to occur during construction due to the travel of construction machinery, etc., until the completion of the development of the field and the handover to the farmer. Note that each field may have different subsidence characteristics. Therefore, the acquisition unit 251 may acquire the expected subsidence amount for each of the multiple divided areas. The expected subsidence amount is used to calculate the amount of soil required when leveling the field.

[0135] When the construction stage is the road construction stage, the acquisition unit 251 first acquires the pavement type. Then, the shape data corresponds to the pavement type. The pavement type includes, for example, gravel pavement, asphalt pavement, concrete pavement, and other pavements. For example, when the pavement type is gravel pavement, the road has, from the bottom, a road body, a roadbed, and a surface layer, as shown in the upper part of FIG. 20. In this case, the meshes that need to be generated are, from the bottom, a road body surface mesh, a roadbed surface mesh, and a surface layer mesh. When the pavement type is asphalt pavement, the road has, from the bottom, a road body, a roadbed, a lower subgrade, an upper subgrade, a base layer, and a surface layer, as shown in the lower part of FIG. 20. In this case, the meshes that need to be generated are, from the bottom, a road body surface mesh, a roadbed surface mesh, a lower subgrade surface mesh, an upper subgrade surface type, a base layer surface mesh, and a surface layer surface mesh. The shape data includes the thickness of each of these layers. Sectional construction, which will be described later, is required for each such layer. In this case, the shape data acquired in the acquisition step includes shape data required for the sectional construction stage. Then, in the generation step, mesh data of at least one of the current structure and the planned structure scheduled for each construction stage of the sectional construction of each layer is generated.

[0136] FIG. 21 is a schematic diagram showing an example of a setting screen for shape data for generating construction mesh data in a drainage channel construction stage. The second acquisition unit 152 according to this embodiment may acquire, for example, numerical data input by a user to an input screen as shown in FIG. 21 as shape data. Then, the second acquisition unit 152 links the acquired shape data to the corresponding skeleton line. The linking method by the second acquisition unit 152 is the same as the linking method by the second acquisition unit 152 of the earth surface data generation device 1 according to the first embodiment. Note that the setting screen for shape data is not limited to the configuration and input items shown in FIG. 21.

[0137] (Generation step) After acquiring the skeleton line data and shape data of the current structure and the planned structure, the process proceeds to the generation step S22. In the generation step S22, each generation unit generates mesh data of at least one of the current structure and the planned structure scheduled for each construction stage using the skeleton line data and shape data of each of the current structure and the planned structure. Specifically, in the generation step S22, at least one of the generation units from the first generation unit 252 to the seventh generation unit 259 generates mesh data of the structure or the land other than the current structure. For example, in the generation step according to this embodiment, mesh data of the surface of the structure or the construction surface in the section construction stage is generated based on the acquired shape data. In addition, the mesh displayed based on the mesh data according to this embodiment is a triangular mesh. However, the shape of the mesh is not limited to this. That is, the mesh displayed based on the mesh data may be a quadrangle or the like.

[0138] In the generation step S22, the first generation unit 252 generates mesh data of the current structures and planned structures of the construction site (construction site), and the seventh generation unit 259 generates mesh data of the land other than the current structures of the construction site from the current topographical information. When the current construction site is a field, two meshes, a base layer and a cultivated layer, are required as mesh data of the current structures. The cultivated layer exists from the ground surface to a specified depth, and the base layer exists below the cultivated layer. In addition, the mesh data of the current construction site may include flumes of irrigation channels, pavement, etc., in addition to the base layer and cultivated layer. These structures are removed during construction, so by understanding their amount, the amount of industrial waste generated by construction can be estimated.

[0139] In the generating step S22, the first generating unit 252 to the sixth generating unit 258 generate mesh data of the structure planned for each construction stage from various data of the current structure and various data of the planned structure. The "mesh data of the structure" is generated using the skeleton line data and the shape data. Specifically, it is generated using the same method as the method used by the earth surface data generating device 1 according to the first embodiment to generate the 3D model. The "construction stage" includes any of the following: land leveling (field) construction, drainage channel construction, ridge construction, road construction, and irrigation channel construction. The "construction" may also include the type of work to bury underground structures such as buried pipes for passing sewerage, water supply, and gas pipes, and box culverts for passing subways, underground electric wires, roads, etc. In this case, the construction is performed, for example, by the second generating unit 254 generating an excavation mesh of a buried trench in the same manner as the drainage channel, and after the ICT construction machine excavates the buried trench, the underground structure is placed in the buried trench and backfilled. The "construction stage" also includes the stage after completion. The mesh data of the structure generated in the generating step according to this embodiment is design mesh data of the surface of the construction target at each construction stage.

[0140] In addition, each construction stage may include a further subdivided section construction stage. For example, in the construction of a field, there is a section construction for excavating to the top surface of the base layer or stripping off the existing cultivated layer for the planned range of the field, and a section construction for constructing a new cultivated layer on the base layer. In such a case, each generation unit generates mesh data of the construction surface in the section construction stage of each structure. That is, in the section construction for excavating to the base surface or stripping off the existing cultivated layer, the base surface is the construction surface of the section construction, and in the section construction for constructing a new cultivated layer on the base surface, the surface (cultivated surface) of the new cultivated layer is the construction surface of the section construction. Therefore, it is necessary to generate mesh data of the construction surface of each section construction. In addition, in the construction stage of a road, as described above, the road body, roadbed, lower subgrade, upper subgrade, base layer, and surface layer are constructed (constructed) in that order. In that case, a mesh of the construction surface of the necessary section construction is generated. Below, we will explain the specific construction procedures for several construction stages and the generation of the necessary construction mesh data, including section construction.

[0141] ·Drainage works (drainage construction) Drainage works are carried out at the very beginning of construction work to handle rainwater generated during the construction period. Specifically, first, primary excavation is carried out to construct a temporary drainage channel. The surface of the primary excavation area is soil. In other words, the temporary drainage channel becomes an earthen channel. After construction such as ground leveling and road construction is completed, secondary excavation is carried out. In secondary excavation, excavation is carried out up to a floor for constructing the foundation (crushed stone or dry-mixed concrete, etc.). The foundation is laid on top of that, and the body of the channel is installed on the foundation. After the body is installed, the area around the body is backfilled, the surrounding slopes are shaped, etc., and a proper drainage channel (open channel) is constructed. In addition, if necessary, a cover is placed on the body to make it an open or closed channel. This method can also be applied to underground pipelines by changing the concrete flume to a pipeline.

[0142] In order to have the ICT construction machine perform the primary excavation and secondary excavation in the drainage work, mesh data of the structure in the drainage channel construction stage is required. When generating mesh data of the structure in the drainage channel construction stage, in the generation step S22, the second generation unit 254 generates mesh data of the structure in the drainage channel construction stage. Specifically, the second generation unit 254 generates mesh data showing the surface shape of the construction site after the primary excavation is completed, mesh data showing the surface shape of the construction site after the secondary excavation, and mesh data including the surface of the drainage channel's skeleton (after the drainage work is completed). The mesh data may include not only the mesh of the outer surface that appears on the ground surface, but also the mesh data of the surface of the skeleton on the underground side. The drainage channel is specified by skeleton line data and shape data, but if the position of the skeleton line (skeleton line data) is changed, the construction mesh is changed accordingly. Also, if the shape of the drainage channel (shape data) is changed, the construction mesh is changed accordingly. This is similar for other structures.

[0143] ·Land preparation work (land preparation work) In land leveling work, for example, when carrying out work to level multiple small fields into one large field, the cultivated layer of each small field is first stripped off. The ICT construction machine recognizes the position of the base layer and strips off the cultivated layer while controlling the blade (blade) so that it does not go below the base layer. The stripped cultivated soil is then stored in another location. If the existing field is to be used as is, there is no need to strip off the cultivated layer. After that, cutting and filling are performed on each base layer of each small field with different altitudes to create a single base layer with the same altitude. The ICT construction machine recognizes the height of the new base layer to be built, cuts off the soil that exists above the recognized height, and moves the cut soil to places below the recognized height. Next, if the field is a rice paddy, a ridge is created on top of the base layer. The ICT construction machine may create an embankment larger than the planned ridge and build the ridge by cutting the embankment so as not to excavate inside the recognized surface shape. The removed cultivated soil is then replaced to create a new cultivated layer. The ICT construction machine recognizes the height of the new cultivated layer and performs leveling work so that the surface of the cultivated layer is at the recognized height.

[0144] In the case where mesh data of the current state structure is required in the ground preparation stage to allow the ICT construction machine to perform the above ground preparation work, the first generating unit 252 generates mesh data of the current state structure and the planned structure in the ground preparation stage. In addition, for land other than the current state structure, the current state topographical information may be used. In the above ground preparation work, there are section construction in which excavation or filling is performed from the surface of the current state structure and the land other than the current state structure to the base layer, section construction in which a ridge is created in the case of a paddy field, and section construction in which a cultivated layer is created. Therefore, the first generating unit 252 generates mesh data of the construction surface of each section construction. Specifically, the first generating unit 252 generates mesh data of the surface of the base layer at the construction position of the field using the skeleton line representing the polygon of the field and the shape data. The mesh data of the surface layer of the cultivated layer is generated using the skeleton line data and the shape data of the field. Furthermore, when the field is a paddy field, the first generating unit 252 also generates mesh data of the surface of the ridge using the skeleton line data and shape data of the ridge.

[0145] The first generating unit 252 also calculates the amount of cultivated soil required to create the cultivated layer of the planned field based on the mesh data of the surface of the current base layer and the mesh data of the surface of the cultivated layer. Specifically, the volume of the space between the surface of the base layer and the surface of the planned cultivated layer is the volume of the required cultivated soil. Meanwhile, the volume of the space between the surface of the current base layer and the surface of the current cultivated layer is the volume of the current cultivated soil. If there are multiple current cultivated layers, the total value of these is used. The volume obtained by subtracting the volume of the current cultivated soil from the volume of the required cultivated soil is the volume of the newly required cultivated soil, which is the amount of soil. This is the amount of soil required for the cultivated layer of the planned field.

[0146] However, when performing land leveling work, the field subsides as the construction machine travels. If the work is performed while ignoring this subsidence, a situation occurs in which the amount of soil required to develop the field so that the surface height of the cultivated layer is a predetermined height is insufficient. For this reason, in designing the field, it is necessary to predict this subsidence and accurately predict the amount of cut and filled soil in advance. Therefore, in the generation step according to this embodiment, the first generation unit 252 generates mesh data of the surface of the base layer, taking into account the expected amount of subsidence (anticipated amount of ground subsidence) that will occur during land leveling work. Specifically, when performing soil volume calculation, the surface height of the current base layer is lowered by the height of the predicted amount of subsidence to calculate the soil volume. Alternatively, the surface height of the planned field may be calculated by raising it by the height of the predicted amount of subsidence.

[0147] ·Round construction (Round construction) When generating mesh data of a structure in the ridge construction stage, in the generation step S22, the third generation unit 255 generates mesh data of the structure in the ridge construction stage. In the generation step S22 according to this embodiment, the third generation unit 255 generates mesh data of the surface of the ridge to be placed on the base layer at the field construction position. The third generation unit 255 according to this embodiment generates mesh data of the surface of the ridge by dividing it into mesh data of the inner top end, mesh data of the outer top end, mesh data of the inner slope, and mesh data of the outer slope, for example. These mesh data can be integrated using dedicated software to form mesh data of the surface of one ridge. The integration of this mesh data may be performed by the third generation unit 255.

[0148] Fig. 22 is a schematic diagram showing an example of a screen on which mesh data for the base surface, cultivated surface, and ridges used in field leveling work is generated. The procedure for generating such mesh data and its use are explained below.

[0149] 2201 in FIG. 22 shows the cross section and elevation of the bedrock surface, cultivated surface, and ridge of the current field acquired by the generating device 2 of mesh data for design and construction. In the parametric model set for each field in the current state, the user can input the thickness (t) of the cultivated layer. Based on this, the first generating unit 252 generates mesh data of the bedrock layer below the current field scene by the thickness of the cultivated layer. The current ridge mesh data is left. The upper side of the figure is the 2D plan view (input data) to be read, and the elevation value of the field scene is written in the upper part, and the thickness of the cultivated layer is written in the lower part. The lower part is what is read by the generating device 2 of mesh data for design and construction (same below). The elevation of the field scene and the thickness of the cultivated layer are reflected in the 3D model. The thickness of the cultivated layer may be written in the 2D plan view in advance, or the user may input it later.

[0150] When ICT construction machinery (mainly bulldozers) is provided with mesh data of the current base layer (base surface) and mesh data of the ridge (surface), the ICT construction machinery can recognize the position of the base layer and refer to the mesh data to control the bulldozer's blade (blade) so that it does not drop below the base layer, and remove the soil in the cultivated layer.

[0151] 2202 to 2204 in Figure 22 show the mesh positions of the base surface, cultivated surface, and ridges of the planned field. 2202 displays the mesh position of the base surface to be created. In the parametric model set for each field in the design, the user can input the thickness of the cultivated layer. Alternatively, it may be specified in advance in a 2D plan view. This generates mesh data for the base surface below the designed field scene by the thickness of the cultivated layer. The mesh data for the ridges is not used at this stage. The elevation of the base surface to be created is determined taking into account the volume of earthwork to be filled and cut. The elevation of the base surface may be set arbitrarily by the user.

[0152] After the ICT construction machinery has stripped away all the cultivated soil in the field, mesh data of the planned foundation surface is provided to the ICT construction machinery (mainly a bulldozer).The ICT construction machinery can then recognize the location of the new foundation layer to be constructed, and will then excavate the areas higher than that location and move the excavated soil to lower areas.

[0153] 2203 is a display image showing the position of the mesh of the ridge to be constructed. In the parametric model set for each field in the design, the user can input the shape of the ridge. In this way, the third generating unit 255 generates a 3D mesh of the designed ridge. Although not shown in 2203, the outer top and outer slope of the ridge may be included.

[0154] Once the construction of the new base layer is complete, mesh data of the planned ridge is provided to ICT construction machinery (mainly backhoes). The backhoe creates embankments larger than the planned ridge, and then the backhoe's blade uses the position information from the mesh data of the ridge to scrape away the soil and build the ridge, being careful not to excavate the inside of the ridge.

[0155] 2204 is a display image showing the position of the mesh of the cultivated layer to be developed. In the parametric model set for each field in the design, the thickness of the cultivated layer is set in the plan, and the first generating unit 252 generates a model of the field scene having mesh data of the base layer and the cultivated layer.

[0156] Once the ridges are completed by the ICT construction machinery, the stockpiled cultivated soil is transported by a carrier dump or similar, and mesh data of the planned cultivated layer is provided to the ICT construction machinery (mainly a bulldozer). The bulldozer can recognize the height of the new cultivated layer, so it carries out leveling work to the specified height.

[0157] ·Road construction (road construction) When generating mesh data of a structure in a road construction stage, in a generation step S22, the fourth generation unit 256 generates mesh data of the structure in a road construction stage. In the generation step according to the present embodiment, the fourth generation unit 256 generates at least one of road surface mesh data, roadbed surface mesh data, lower layer roadbed surface mesh data, upper layer roadbed surface mesh data, base layer surface mesh data, and surface surface (road surface) mesh data in road construction. Note that the fourth generation unit 256 does not need to generate all of these mesh data, and it is sufficient to generate at least one of them.

[0158] ·Irrigation canal construction (Irrigation canal construction) When generating mesh data of a structure in the irrigation channel construction stage, in the generation step S22, the fifth generation unit 257 generates mesh data of the structure in the irrigation channel construction stage. The method of generating mesh data of a structure in the irrigation channel construction stage is basically the same as the method of generating mesh data of a structure in the drainage work construction stage. If the position of the skeleton line is changed, the construction mesh is changed accordingly.

[0159] In the generation step S22, the sixth generation unit 258 also generates mesh data of the completed structure. The completed mesh data is generated using the field elevation value after land grading, which is set by comprehensively considering the amount of fill and cut in the construction area, the required height from the bottom of the drainage channel, and the required height from the bottom of the irrigation channel. The completed mesh data may be reviewed and changed from time to time before or during construction in response to requests from local residents and the amount of land subsidence. The elevations of the field areas to be land grading and each field area are determined by taking into consideration the elevations of the drainage channel and irrigation channel, the amount of fill and cut, the difference in elevation between the road and the rice field surface, and the economics of construction costs. If various data (skeleton line data and / or shape data) are changed in the planning stage, each generation unit regenerates the design mesh data together with the mesh data for each construction stage. If various data are changed in the construction stage, each generation unit regenerates the design mesh data together with the mesh data for each construction stage.

[0160] When the first generation unit 252 to the seventh generation unit 259 generate mesh data, they link the mesh data to an ID assigned to each structure (e.g., a field, etc.). As a result, each mesh data is managed as a construction surface mesh (e.g., a cultivated surface mesh, a base surface mesh, a ridge mesh, etc.) for the sectional construction of the structure. When the structure is a field and one field ID corresponds to multiple fields, it becomes necessary to manage a mesh for each field. For this reason, a branch number is assigned to each field corresponding to the same field ID, and the mesh data is linked to the branch number.

[0161] (13. Output Step) After the various mesh data are generated, the process proceeds to an output step S23. In the output step S23, the output processing unit 260 outputs the generated mesh data to the output unit 13. This output processing unit 260 also has the function of the data output processing unit 163 according to the first embodiment. If the output unit 13 is a terminal to which a cable leading to a monitor is connected, or the monitor itself, the 3D mesh is displayed on the monitor in this step. If the output unit 13 is a communication unit that communicates with other devices, or a drive that writes 3D model data to media, the mesh data is provided to other devices, etc. in this step.

[0162] The following are some of the characteristics of the output mesh. First, the meshes are managed according to the construction stage. Specifically, mesh groups are linked to a certain skeleton line in descending order of size. Furthermore, for a drainage channel, a concrete flume mesh, a ground surface mesh (divided into left and right) from the outer edge of the concrete flume to the connection line, and a ground surface mesh or slope mesh (also divided into left and right) generated from the connection line are generated and output. In addition, a ground surface mesh or slope mesh generated from the end connection line, and a mesh for ICT construction used for each construction stage are generated and output. Furthermore, data for the completed mesh is saved as several parts, such as left and right meshes, and output. These meshes are classified into at least one category by skeleton line, and multiple categories within the skeleton line. Since they are classified in this way, the user can select and use the mesh he needs.

[0163] [Action and Effect] According to the generating device, generating method, and generating program described above, a 3D model is generated using skeleton lines and shape data, and a construction mesh can also be created. In other words, when the skeleton line data or shape data of a structure is changed, the mesh data for each construction stage is changed accordingly. This reduces the effort required to generate and change the 3D mesh after completion of the field and the 3D mesh for each construction stage. In addition, since the mesh after completion and the mesh at the construction stage are linked, it is expected that human errors during work will be reduced. In the conventional technology, the 3D model is generated individually by direct modeling, but in this embodiment, in addition to generating the ground surface between the structures by the parametric model, construction mesh data and completed mesh data can also be generated.

[0164] [Embodiment 3] Next, another embodiment of the present invention will be described in detail with reference to the drawings. For convenience of description, the same reference numerals are attached to members having the same functions as the members described in the above-mentioned embodiments 1 and 2, and the description thereof will not be repeated. FIG. 23 is a block diagram showing the configuration of a top surface generating device 3 according to this embodiment 3. The top surface generating device 3 is a device that generates the top surface (ground surface) of the slopes that are overlapped vertically and formed around a plurality of structures defined by shape data. The top surface is also called the ground surface because it is a surface that connects the surfaces with the highest elevation among the overlapping surfaces. In this embodiment, the top surface generating device 3 first generates the top surface of the plurality of slopes that are formed around each structure for each structure. Then, after the top surfaces of the slopes of all the structures are generated, the top surface with the highest elevation is generated from the top surfaces that are overlapped vertically.

[0165] 23, the top surface generating device 3 includes an input unit 11 and an output unit 13 similar to those of the earth's surface data generating device 1 according to the first embodiment, as well as a control unit 35 and a storage unit 34. The top surface generating device 3 may include an operation unit 12 (not shown) in addition to the input unit 11. The configurations and functions of the input unit 11, operation unit 12 and output unit 13 are similar to those described in the first embodiment, and therefore will not be described here.

[0166] The storage unit 34 stores a top surface generation program 341. The top surface generation program 341 describes the flow of the top surface generation process executed by the control unit 35. The storage unit 34 according to this embodiment is configured with a semiconductor memory or a hard disk. Note that when the generation program is not required (for example, when the control unit 35 performs all of the various calculations described below using a logic circuit), the top surface generation device 3 does not need to include the storage unit 34.

[0167] The control unit 35 controls the entire top surface generating device 3. The control unit 35 includes an acquisition unit 351, a slope generating unit 352, an extraction unit 353, and an output processing unit 354. The acquisition unit 351 acquires at least one of the connection lines of the structures and the ground edge lines, which are the outer edge lines of the ground surface generated at a predetermined distance from the connection lines. The slope generating unit 352 generates a slope having a downward gradient or an upward gradient from at least one of the acquired connection lines and the ground edge lines to the base ground. The magnitude of the downward gradient and the upward gradient is determined in advance as shape data. The base ground is a virtual ground that serves as a reference. As described above, the elevation of the base ground can be determined by, for example, acquiring the lowest elevation value among the elevations of the nodes of all the connection lines, and lowering the elevation value by an arbitrary height from that elevation value. The extraction unit 353 extracts the top surface using a plane extraction method that extracts the uppermost surface from among the overlapping slopes generated. With this method, the top surface generation device 3 connects the top surfaces from among the overlapping surfaces to generate a top surface mesh. The top surface mesh is a mesh that constitutes the top surface.

[0168] The output processing unit 354 accumulates image data or numerical data including the extracted top surface, and outputs it to the outside via the output unit 13. The control unit 35 realizes the functions of an acquisition unit 351, a slope generation unit 352, an extraction unit 353, and an output processing unit 354 by reading and executing a top surface generation program 341 stored in the storage unit 34.

[0169] Next, a description will be given of each part of the control unit 35. First, the acquisition unit 351 acquires the coordinates of the nodes of the connection lines of the structures stored in the storage unit 34. The coordinates of the nodes are stored in, for example, a CSV (Comma Separated Value) format.

[0170] Next, the ground surface generating unit 355 generates a ground surface. The ground surface generating unit 355 generates a ground surface line by extending a predetermined distance from two adjacent nodes on the road connection line in a direction that bisects the angle formed by the connection lines on both sides of the node and is perpendicular to the skeleton line. Then, the ground surface is generated by connecting the tips of the two adjacent ground surface lines. This is repeated for all nodes. The line connecting the tips of the ground surface lines is called a ground edge line. The ground surface may be a twisted surface or may be open.

[0171] The acquisition unit 351 acquires the coordinates of the road connection line and the ground edge line. The structure connection line is a polygon or polyline that indicates the boundary of the structure and is associated with the structure's skeleton line as described above. The acquisition unit 351 acquires the three-dimensional coordinates of the nodes of the connection line and the three-dimensional coordinates of the nodes of the ground edge line (the tip of the ground surface line).

[0172] The ground surface is a plane defined by the two adjacent ground surface lines obtained as described above and the connection line between the two nodes that are the starting points of the two adjacent ground surface lines. The ground surface edge line is a collection of straight lines that connect the ends of the ground surface lines. In other words, the ground surface edge line is obtained by connecting points that are a predetermined distance from the connection line (for example, the node on the connection line). Hereinafter, the end of this ground surface line is referred to as the node of the ground surface edge line. The acquisition unit 351 sends data of at least one of the acquired nodes of the connection line and the ground surface edge line to the slope generation unit 352.

[0173] FIG. 25 is a schematic diagram showing data of the nodes and slope lines of the ground edge line of a road (shown in dark color in the figure) acquired by the acquisition unit 351. For ease of understanding, FIG. 25 omits the road connection lines and ground surface lines, and shows only the slope generated from the nodes of the ground edge line. FIG. 25 shows four nodes 1 to 4, and their coordinates are shown as (x1, y1, z1), (x2, y2, z2), (x3, y3, z3), and (x4, y4, z4). In addition, the intersection point 5 between the slope line generated from node 1 and the base ground 100 is shown as (x5, y5, z5). Similarly, intersections 6 to 8 between the normal lines generated from nodes 2 to 4 and the base ground 100 are indicated by coordinates (x5, y5, z5), (x6, y6, z6), (x7, y7, z7), and (x8, y8, z8), respectively.

[0174] The slope generating unit 352 generates a slope having a predetermined downward or upward gradient from the connection line or ground edge line of the structure to the base ground 100 (slope generating step). The slope is a surface generated between the slope lines generated with a predetermined downward or upward gradient from two adjacent nodes of the connection line or ground edge line. The shape of the slope is a quadrangle including a part of the connection line or ground edge line as one side. The connection line may be a closed connection line or an open connection line. The same applies to the ground edge line. "Closed" refers to the case where the angle formed by the two connection lines or ground edge lines connected at the node toward the outside of the structure is less than 180 degrees. "Open" refers to the case where the angle formed by the two connection lines or ground edge lines connected at the node toward the outside of the structure is 180 degrees or more. The slope generation step is a step of generating a quadrangular plane by connecting two adjacent slope lines generated from the connection line or ground edge line and the upper and lower end points of the slope lines. In the case of an open connection line or open ground edge line, the slope lines generated from the nodes often do not intersect, but for example, when a single road that curves in a zigzag shape faces each other, the slopes generated from the facing connection lines or ground edge lines may intersect with each other, so in this case, the top surface is generated by applying the plane method.

[0175] The slope is a surface defined by a straight line between two nodes of the connection line or the ground edge line, two normal lines generated from the two nodes, and a straight line connecting two points where the two normal lines contact the base ground 100. The magnitude of the downward or upward slope is determined as shape data by the user, for example.

[0176] FIG. 26 is a schematic diagram showing a slope generated by the slope generating unit 352 according to the first embodiment. 401 in FIG. 26 is a diagram showing a slope generated from a slope line drawn from nodes 1 and 2, and is a surface formed by nodes 1 and 2, and intersections 5 and 7 between the slope line and the base ground 100. 402 in FIG. 26 is a diagram showing a slope generated from a slope line drawn from nodes 3 and 4, and is a surface formed by nodes 3 and 4, and intersections 6 and 8 between the slope line and the base ground 100. 403 in FIG. 26 is a diagram showing a method of generating a slope when the slope lines intersect with each other. In this case, since the slope line from node 2 and the slope line from node 3 intersect, the lower ends 6 and 7 of the slope lines are swapped to reconstruct the slope. Specifically, the slope is formed by connecting node 2, node 3, intersection 7 between the slope line from node 2 and the base ground 100, and intersection 6 between the slope line from node 3 and the base ground 100 in this order.

[0177] Note that FIG. 26 (FIG. 25) is simplified for ease of understanding. In reality, there are two normal lines generated from node 2, namely, normal line 27 corresponding to line segment 12 (the line segment connecting node 1 and node 2 will be referred to as "line segment 12", and the same applies below), and normal line 27' (not shown) corresponding to line segment 23. Then, an intersection line between the slope generated from line segment 12 and the slope generated from line segment 23 is obtained. Similarly, there are two normal lines generated from node 3, namely, normal line 36' (not shown) corresponding to line segment 23 and normal line 36 corresponding to line segment 34. Then, an intersection line between the slope generated from line segment 23 and the slope generated from line segment 34 is obtained.

[0178] The extraction unit 353 extracts the top surface of the slopes that are generated by overlapping one above the other using a plane extraction method. As described above, the slopes are based on the straight line between the two nodes of the connection line or the ground edge line, so many slopes are generated by overlapping one above the other in various directions. The plane extraction method is a method for extracting the top surface from these slopes. The top surface is the surface with the highest elevation among the surfaces that overlap one above the other, and is also called the ground surface.

[0179] Fig. 24 is a flowchart showing the flow of the top surface generation method S30 executed by the top surface generation device 3. As shown in Fig. 24, the top surface generation method S30 includes steps S31 to S33. Fig. 24 shows a process of generating a normal line from the shared connection line (some of which also include ground edge lines) for structures grouped together in units of shared connection lines (the shared connection line always has a loop shape), and performing Boolean processing along the shared connection line to generate the top surface. At this time, all meshes on the lower surface may be erased. This is performed for each individual structure.

[0180] Step S31 is an acquisition step in which the acquisition unit 351 acquires at least one of the connection line of the structure and the ground edge line, which is the outer edge line of the ground surface generated at a predetermined distance from the connection line. The predetermined distance is determined in advance by the user and is not particularly limited, but may be, for example, several tens of centimeters to several meters. Alternatively, the predetermined distance may be determined for each structure, and the acquisition unit 351 may acquire the numerical value.

[0181] Step S32 is a slope generation step in which the slope generation unit 352 generates a slope having a downward gradient or an upward gradient from at least one of the acquired connection line and ground edge line to the base ground. The magnitude of the downward gradient or upward gradient is specified as, for example, shape data. The slope is generated as mesh data. For example, the slope is generated in the form of triangular mesh data. Note that a slope without twists may be generated as a quadrilateral mesh. The method of generating the mesh data of the slope will be described in detail later.

[0182] Step S33 is an extraction step in which the extraction unit 353 extracts the top surface using a plane extraction method that extracts the uppermost surface of the overlapping slopes generated. As will be described later, the extraction unit 353 may extract not only the slopes but also the top surface of the structure and the ground surface. Note that the plane extraction method cannot be applied when an upwardly sloping slope is included. The method of extracting the top surface when an upwardly sloping slope is included will be described later.

[0183] The top surface generating method S30 may include step S34. Step S34 is an output step in which the output processing unit 354 generates and outputs image data or numerical data including the extracted top surface. The numerical data is, for example, three-dimensional coordinate data of the vertices of the mesh of the surface. The image data is, for example, outline drawing data obtained by synthesizing all the meshes to provide a three-dimensional bird's-eye view. The generated image or numerical data of the top surface is output to the outside via the output unit 13. Hereinafter, generating numerical data of the surface mesh is referred to as generating a surface.

[0184] The plane extraction method will be described below with reference to the drawings. Fig. 27 is a flowchart showing the flow of the plane extraction method S33 executed by the extraction unit 353. The plane extraction method S33 includes steps S331 to S334.

[0185] Step S331 is a step in which the extraction unit 353 divides a slope whose four vertices are not on the same plane into two triangles. A slope whose four vertices are not on the same plane is also called a "twisted slope." The extraction unit 353 divides such a twisted slope into two triangles between the opposing vertices. A twisted slope may also be generated when the ground surface and the slope are connected without using a switching line. Note that when generating a triangular mesh, the slope is divided into two triangles even if the four vertices are on the same plane.

[0186] Fig. 28 is a schematic diagram showing how a twisted slope is divided into two triangles between opposing vertices. 601 in Fig. 28 shows how slope 1-2-7-5 is divided into two triangles, 1-2-7 and triangle 1-5-7. Similarly, 602 in Fig. 28 shows how slope 3-4-8-6 is divided into two triangles, and 603 shows how slope 2-3-7-6 is divided into two triangles.

[0187] If the intersection point of the slope line 27 and the slope line 36 is 9, and the intersection point of the slope toe line of the line segment 12 and the line segment 37 on the base elevation surface is 10, then the vertices of the slope generated from the line segment 12 are 1, 2, 9, 10, and 5. These are all on the same plane, and the triangle mesh is divided from these five points. There are various combinations of lines for dividing the triangle mesh. For example, an evaluation function may be used to generate the triangle mesh so that all the triangle meshes are close to equilateral triangles.

[0188] A method for determining whether or not a slope is twisted will be described with reference to Fig. 29 and Fig. 30. Fig. 29 is a schematic diagram showing a plane passing through three points A, B, and C. The normal vector n of this plane is expressed by the following (Equation 1) using a vector AB pointing from A to B and a vector AC pointing from A to C.

number

[0189] Here, if the origin is represented by O and the position vector OA of point A is represented by the following (Equation 2), the plane equation is expressed by the following (Equation 3).

number

number

[0190] 30 is a schematic diagram showing a plane that passes through three points A, B, and C, and a distance L between the plane and a point D. It is assumed that the plane that passes through the three points A, B, and C is expressed by the following plane equation (Formula 4).

number

number

[0191] In this case, the distance L between the plane and point D is expressed by (Equation 6).

number

[0192] If this distance L is sufficiently small, for example, 0.001 (unit: coordinate unit) or less, the extraction unit 353 can determine that points A, B, C, and D are on the same plane. In this case, the plane ABCD is determined to be not twisted. Conversely, if it is determined that points A, B, C, and D are not on the same plane, the plane ABCD is determined to be twisted. In that case, the extraction unit 353 divides the plane ABCD into two triangles.

[0193] Returning to FIG. 27, in step S332, the extraction unit 353 derives the intersection points where any three slopes overlap for all combinations of three slopes.

[0194] Fig. 31 is a diagram showing an intersection 91 where three slopes overlap. The three surfaces in this case are surface A 601, surface B 602, and surface C 603 in Fig. 28. In this manner, the extraction unit 353 searches for an intersection for any combination of three slopes.

[0195] We will explain how to find the intersection point where three slopes overlap. The three slopes are expressed by the following (Equation 7).

number

[0196] The intersections in this case are expressed using the following matrices (Equation 8), (Equation 9), (Equation 10), and (Equation 11).

number

number

number

number

[0197] Here, if the rank of matrix A is 3, then an intersection exists. If the rank of matrix A is 2, then a shared line exists, and if it is 1, then a shared surface exists. Therefore, the rank of matrix A is confirmed, and if it is 3, then the intersection is derived using the following (Equation 12).

number

[0198] The following method is used to determine whether the derived intersection exists within the three finite planes used in the derivation. It is assumed that the normal faces of all quadrilaterals are divided into triangles, and the following method is used to determine whether an intersection exists on the plane of a triangle. If the vertices of a triangle are A, B, and C, and point P inside the triangle is expressed using vector CA from vertex C to A, and vector CB from vertex C to B, it can be expressed as (Equation 13).

number

[0199] When (Equation 13) is transformed using a position vector from the origin O, point P inside the triangle is expressed by (Equation 14).

number

[0200] Here, if the coordinates of point P are expressed using (Equation 15), they are expressed as (Equation 16).

number

number

[0201] By solving the simultaneous equations shown in (Equation 16), (s, t, u) are found, and if they satisfy the condition in the following (Equation 17), point P is determined to be a point inside the triangle. In other words, point P is determined to be an intersection that exists within a finite plane, and is determined to be a correct intersection.

number

[0202] Next, the extraction unit 353 deletes, from among the derived intersections, those that overlap with vertices of the slope of an existing quadrangle (step S332 in FIG. 27). FIG. 32 is a schematic diagram showing a portion where the intersections derived as described above overlap with existing vertices. Specifically, the intersections indicated by the circles in FIG. 32 overlap with vertex 3 of the existing slope shown in FIG. 25, and are therefore deleted from the intersections. An existing vertex is, for example, a node on a connection line. When determining the intersections, the nodes are also detected as intersections, and therefore it is necessary to delete these nodes.

[0203] Next, the extraction unit 353 integrates the closest points among the intersections or existing vertices (step S333 in FIG. 5). The closest points are points that should theoretically be in the same position, but because of errors that occur when performing numerical calculations, the closest points are used. FIG. 33 is a schematic diagram showing an example of points to be integrated. In the example shown in FIG. 33, two points, the intersection of faces 1, 2, and 4 and the intersection of faces 1, 3, and 4, are generated at the positions indicated by circles and are in the same position. Therefore, these are integrated into one intersection.

[0204] Next, the extraction unit 353 invalidates the vertices of the slopes below the uppermost slope and combines the remaining vertices to form a new mesh (step S334 in FIG. 27). FIG. 34 is a schematic diagram showing vertices below the uppermost slope. In the example shown in FIG. 34, vertices 6 and 7 are the vertices to be deleted, and three reconstructed slopes are shown. The reconstruction method involves generating a set of vertices present on each slope. Then, for each set, a slope of a polygon made up of those vertices is generated.

[0205] A method for determining whether a point is below a certain plane will be described. Suppose a certain plane is expressed by the following (Equation 18).

number

number

number

number

[0206] The extraction unit 353 may further extract the upper surface of the structure. This makes it possible to generate the uppermost surface that combines the uppermost surface of the slope and ground surface with the upper surface of the structure.

[0207] The above extraction step has been described as a method of generating a slope from the connection line or ground edge line of a single structure and extracting its top surface. Since there are actually multiple structures, the acquisition step, slope generation step, and extraction step are performed for each individual structure (first-order plane method). Then, the plane extraction method is used again for the top surface generated for each structure to generate the overall top surface including all structures (second-order plane method). In the first-order plane method, structures other than the target structure are ignored when generating the top surface. In this case, the two structures that intersect in substance are considered to be one composite structure.

[0208] In the above embodiment, the slope has been described as having a downward or upward slope from the connection line of the structure or the ground edge line. In the case of a slope with an upward slope, the structure and the surface of the slope are turned upside down, and the above-mentioned processing is performed while regarding the upward slope as a downward slope. The details of this method will be described later.

[0209] As mentioned above, the ground edge line is basically obtained by connecting points at a specified distance from the nodes of the connection line. However, when the direction of the connection line changes in the closing direction before and after the node, the position of the point at a specified distance from the node may change irregularly and intersect. If the ground edge lines intersect, it is not possible to generate a slope from the ground edge line. Therefore, it is necessary to generate a new joint ground edge line that does not intersect.

[0210] A method for determining whether ground end lines intersect will be described below. FIG. 35 is a schematic diagram showing a method for determining whether ground end lines intersect and, if they do, generating new ground end lines. FIG. 35 shows a view of a connection line projected onto a horizontal plane from above. As shown at 1301 in FIG. 35, assume a case where a connection line exists from a nodule point P1 indicated by a white circle through nodule points Pi, Pn, Pk to a nodule point Pm. Nodule points indicated by black circles of the corresponding ground end lines are generated from Q1 through Qi, Qn, Qj, Qk to Qm. The nodule point Q is the end point of a normal vector that has a length of the ground surface line from the nodule point P and extends in a direction orthogonal to the connection line. The nodule point Q has the same elevation as the nodule point P. The connection line is straight from the nodule point P1 to the nodule point Pn, and the connection line changes direction by 90° at the nodule point Pn. At this time, for the ground end line, Qn and Qj are generated due to the change in the direction of the connection line.

[0211] Here, a line segment constituting a ground end line is denoted as seg, and the i-th line segment is denoted as seg[i]. When seg[i] and seg[j] (i < j) intersect, as shown at 1302 in FIG. 35, seg[i] to seg[j] are deleted, and a line segment connecting the start point Qi of seg[i] and the intersection point Qx, and a line segment connecting the intersection point Qx and the end point Qk of seg[j] are added.

[0212] For the intersection point Qx, the x coordinate and the z coordinate (both orthogonal coordinate axes of the horizontal plane) are set to the intersection point coordinates at the time of intersection determination, and the y coordinate (coordinate axis in the height direction) is set to the average value of the y coordinates of each point from the end point of seg[i] to the end point of seg[j]. Finally, a ground surface line connecting the nodule point Pn, which is the generation source of the deleted points, and the intersection point Qx is generated. When the number of elements in the seg list is N, i is searched from 0, 1, 2... N, and j is searched from N, N - 1,... i + 1.

[0213] The output processing unit 354 generates and outputs an image or numerical data including the uppermost normal plane (ground surface) extracted as described above (step S34 in FIG. 24).

[0214] According to the above-described top surface generating device 3 and top surface generating method S30, it is possible to obtain a top surface formed by combining slopes or ground surfaces generated between structures.

[0215] [Embodiment 4] Next, another embodiment of the present invention will be described in detail with reference to the drawings. For ease of explanation, the same reference numerals are given to components having the same functions as those described in the above embodiments 1 to 3, and the explanations thereof will not be repeated. Fig. 36 is a block diagram showing the configuration of a ground surface data generation device 1A according to this embodiment 4. The ground surface data generation device 1A has a function of generating slopes having berms in addition to a function of generating ground surface data similar to that of the ground surface data generation device 1A according to embodiment 1.

[0216] As shown in the figure, the earth surface data generation device 1A includes an input unit 11, an operation unit 12, and an output unit 13 similar to those of the earth surface data generation device 1 according to embodiment 1, as well as a storage unit 14A and a control unit 15A. The configurations and functions of the input unit 11, the operation unit 12, and the output unit 13 are similar to those described in embodiment 1, and therefore will not be described here.

[0217] The memory unit 14A stores an earth surface data generation program 142. The earth surface data generation program 142 describes the flow of the earth surface data generation process executed by the control unit 15A. The memory unit 14A according to this embodiment is configured with a semiconductor memory or a hard disk. Note that when the earth surface data generation program is not required (for example, when the control unit 15A performs all of the various calculations described below using logic circuits), the earth surface data generation device 1A does not need to be equipped with the memory unit 14A.

[0218] The control unit 15A controls the entire earth surface data generation device 1 A. The control unit 15A includes an acquisition unit 151A and a surface generation unit 161A in addition to the second acquisition unit 152, the interpolation unit 153, the global order setting unit 154, the determination unit 155, the connection line generation unit 156, the shared connection line generation unit 157, the pairing unit 158, the pair information setting unit 159, the switching line generation unit 160, the warning information extraction unit 162, the data output processing unit 163, and the change unit 164 similar to those of the earth surface data generation device 1 according to the first embodiment.

[0219] (Acquisition Department) When a slope having a berm is generated as a slope, the acquisition unit 151A further acquires height data and width data of the berm in addition to the skeleton line data and the elevation data. When a slope having two or more berms is generated, the acquisition unit 151A further acquires height data of each of the two or more berms. The height data is a value indicating the difference in height between the berm and the elevation of a node on a connection line forming the upper end (lower end) of a structure on which the berm is provided (how much it has descended from the upper end in the case of a downward slope, and how much it has ascended from the lower end in the case of an upward slope). The acquisition unit 151A may acquire a numerical value included in the two-dimensional CAD data or three-dimensional CAD data as the height data or width data, or may acquire a numerical value inputted into a predetermined input screen such as that shown in FIG. 21 as the height data or width data.

[0220] (Surface generation part) As shown in FIG. 37, the surface generation unit 161A includes a slope generation unit 1611, a starting point setting unit 1612, a division line generation unit 1613, a deletion unit 1614, a ground surface generation unit 1615, a second slope generation unit 1616, and an extraction unit 1617.

[0221] (Slope generation section) The slope generating unit 1611 generates a slope from the section connection line L21 whose master-slave relationship in the pair connection line L21 is the master. Specifically, the slope generating unit 1611 first generates slope lines that are orthogonal to the section connection line L21 and incline from a plurality of nodes P2 set on the section connection line L21 whose master-slave relationship in the pair connection line is the master, as shown in FIG. 38, for example. Then, the slope generating unit 1611 generates a slope having the section connection line L21 and the pair of slope lines as three sides. Note that, although FIG. 38 illustrates an example of generating a downward slope, when the elevation of the section connection line L21 whose pair information indicates the master is lower than that of the section connection line L21 whose pair information indicates the slave, the slope generating unit 1611 may generate an upward slope that rises from the section connection line L21 whose pair information indicates the master.

[0222] (Starting point generator) The start point setting unit 1612 sets a plurality of bench start points P3 on the slope, which serve as starting points for generating benches, based on the height data acquired by the acquisition unit 151A. Specifically, as shown in Fig. 39, the start point setting unit 1612 sets points on a pair of adjacent slope lines on the slope, whose altitudes are equal to the values ​​indicated by the height data, as the bench start points P3.

[0223] Although only one slope is illustrated in FIG. 39, normally, other section connection lines are connected to the section connection line of the slope, as shown in FIG. 40. Therefore, the surface generating unit 161A generates other slopes adjacent to the slope and having other berms from the other section connection lines. In this case, a process for smoothly connecting the slope and the other slope is required. Therefore, the start point setting unit 1612 according to this embodiment first calculates the coordinates of a first intersection P4, which is an intersection point of an intersection line L8 between the slope and the other slope and a line segment connecting the row of berm start points P3 set on the slope. Next, the start point setting unit 1612 calculates the coordinates of a second intersection P5, which is an intersection point of an intersection line L8 with a line segment connecting the row of berm start points P3 set on the other slope. Next, the start point setting unit 1612 calculates an average coordinate, which is an average of the coordinates of the first intersection and the coordinates of the second intersection, as a new berm start point P3. The start point setting unit 1612 then generates a demarcation line L9 as shown in Fig. 38 based on the sub-bench start point P3. Specifically, the start point setting unit 1612 sets a group of intersection lines L8 that are connected via a singular point as shown in Fig. 41, among the intersection lines L8 between multiple slopes in the 3D topographical data, as an intersection line group. The start point setting unit 1612 then calculates the average elevation of each sub-bench start point P3 for the multiple intersection lines L8 included in the intersection line group. The elevation of each sub-bench start point P3 is then changed to the calculated average elevation, and a straight line connecting each sub-bench start point P3 is generated as the demarcation line L9.

[0224] (Laying line generation section) The demarcation line generating unit 1613 generates a demarcation line L9 connecting multiple sub-bench start points P3. As a result, the slope is divided by the demarcation line L9 into a portion that contacts the section connection line L21 that is the base end of the slope, and a portion that does not contact the section connection line L21.

[0225] (Deletion section / Extraction section) As shown in FIG. 38, the deletion unit 1614 deletes the portion of the slope that is not in contact with the section connection line L21 (the portion located below the section line L9 in FIG. 38, or the portion located above the section line L9 in the case of an uphill slope). When a berm is generated on a terrain in which one slope intersects with another slope as shown in FIG. 40, and the section connection line of the one slope and the section connection line of the other slope are closed, the slope and the other slope will interfere with each other. In such a case, after generating the other slope adjacent to the slope, the extraction unit 1617 extracts the intersection line between the one slope and the other slope using a plane extraction method that extracts the uppermost surface, and further extracts the topmost surface from each of the one slope and the other slope. Specifically, the parts of the slope that are located above the other slopes and the parts of the slopes that are located above the other slopes are extracted (the parts of the slope that are located below the other slopes and the parts of the slopes that are located below the other slopes are deleted). The method of extracting the slope parts using the plane extraction method is the same as the method performed by the top surface generating device 3 according to the third embodiment (shown in Figures 24 to 34). Then, the deletion unit 1614 deletes the part that is not in contact with the section connection line L21 of the two parts separated by the division line L9 on each of the extracted top surfaces.

[0226] (Ground surface generation part) Based on the width data, the ground surface generating unit 1615 generates a ground surface of the bench that is horizontal or inclined less than the slope gradient from the division line L9 so that the width is the width indicated by the width data. Specifically, the ground surface generating unit 1615 generates ground surface lines that are horizontal or inclined less than the slope gradient from each bench start point P3 of the pair of slope lines and have a predetermined extension length. Then, a ground surface is generated whose four sides are the division line L9, the pair of adjacent ground surface lines, and the ground edge lines connecting the tips of the pair of ground surface lines. This generated ground surface becomes the top surface of the bench.

[0227] As described above, another slope having another berm is generated next to the slope. When the first division line dividing the slope and the first division line dividing the other slope are closed (the angle θ toward the outside of the structure is smaller than 180 degrees), the ground surface forming the upper surface of the berm and the other ground surface forming the upper surface of the other berm interfere with each other. In such a case, as shown in FIG. 35, the ground surface generating unit 1615 first obtains a first normal vector having a starting point at a node forming one end of the first division line and a dividing line intersection (node) connecting the first division line and the second division line. The first normal vector is a normal vector that is perpendicular to the first division line, extends toward the outside of the structure, and has a length equal to the width indicated by the width data. Then, the ground surface generating unit 1615 places a new node at the end point of each first normal vector, the elevation of which is equal to the start point of each first normal vector. Then, the ground surface generating unit 1615 generates a first ground edge line with both nodes as both ends. Also, the ground surface generating unit 1615 obtains a second normal vector with the node at one end of the second division line and the division line intersection as its start point. The second normal vector is a normal vector that is perpendicular to the second division line, extends toward the outside of the structure, and has a length equal to the width indicated by the width data. Then, a new node at the end point of each second normal vector, the elevation of which is equal to the start point of each second normal vector, is placed. Then, the ground surface generating unit 1615 generates a second ground edge line with both nodes as both ends.

[0228] After generating the first ground edge line and the second ground edge line, the ground surface generating unit 1615 performs an intersection judgment between the first ground edge line and the second ground edge line. The intersection judgment is performed by judging whether or not the line segment formed by projecting the first ground edge line and the second ground edge line onto the XY plane, that is, the horizontal plane, has an intersection point. If the result of the intersection judgment shows that the first ground edge line and the second ground edge line intersect (judging that the projected line segment has an edge line intersection point), the ground surface generating unit 1615 deletes the parts between the intersection point and the connection line from the first ground edge line and the second ground edge line, respectively. Then, a new ground edge line including the first partial edge line and the second partial edge line, which are the parts remaining after the deletion, is generated. The z coordinate of the end line intersection Qx is set to the average of the z coordinates of each node on the first division line and the z coordinates of each node on the second division line, and the z coordinate of the intersection is updated. Then, the ground surface generation unit 1615 connects the division line intersection and the end line intersection Qx with a ground surface line (straight line). Then, the ground surface generation unit 1615 generates a first ground surface passing through the first division line, the ground surface line, and the first partial connection line, and generates a second ground surface passing through the second section connection line, the ground surface line, and the second partial connection line.

[0229] However, if there are few nodes in a section (near a section line intersection) where the division line where the elevation changes bends, the ground surface generated in that section becomes rough, and a case may occur where the ground surface that should be horizontal is not generated horizontally. In this case, the ground surface generating unit 1615 calculates a third normal vector and a fourth normal vector starting from the end line intersection Qx as shown in FIG. 42. The third normal vector is a normal vector that is perpendicular to the first partial end line and extends toward the inside of the structure. The fourth normal vector is a normal vector that is perpendicular to the second partial end line and extends toward the inside of the structure. Then, the ground surface generating unit 1615 places nodes at the intersection of the third normal vector and the first division line and the intersection of the fourth normal vector and the second division line. Next, the ground surface generating unit 1615 obtains the angle θ between the third (fourth) normal vector and the ground surface line. Next, the ground surface generating unit 1615 equally divides the formed angle θ by an appropriate number n, and linearly interpolates between the third (fourth) normal vector and the ground surface line with a plurality of interpolation vectors Va, Vb, Vc, etc., which start from the end line intersection point Qx and change direction by the equally divided angle θ / n each. Then, the ground surface generating unit 1615 places nodes at each intersection point between each interpolation vector and the first (second) division line. Then, in addition to the first ground surface and the second ground surface, the ground surface generation unit 1615 generates a new ground surface whose three sides are the third (fourth) normal vector, the interpolation vector and the first (second) partition line, and a new ground surface whose three sides are two adjacent interpolation vectors and the first (second) partition line.

[0230] On the other hand, if the first division line dividing the slope and the first division line dividing the other slope are open (the angle toward the outside of the structure is greater than 180 degrees), a gap will be generated between the ground surface and the other ground surface as it is. In such a case, as shown in FIG. 43, before generating the ground surface, the ground surface generating unit 1615 first obtains a first normal vector V1 of the first section connection line L21 and a second normal vector V2 of the second section connection line L21, each of which has a node P2 connecting the first section connection line L21 and the second section connection line L21 as a starting point. Next, the angle θ between the first normal vector V1 and the second normal vector V2 is obtained. Next, the ground surface generating unit 1615 equally divides the angle θ by an appropriate number n, and linearly interpolates between the first normal vector and the second normal vector with a plurality of interpolation vectors Va, Vb, Vc, etc., which start at the node P2 and change direction by the equally divided angle θ / n. Next, the ground surface generating unit 1615 places a new node P2 at the end point of each of the interpolation vectors, which has the same altitude as the node P2, which is the start point of each vector. Next, the ground surface generating unit 1615 generates ground edge lines connecting the new nodes P2. Then, a new ground surface with the first normal vector, the interpolation vector, and the ground edge line as three sides, a new ground surface with two adjacent interpolation vectors and ground edge lines as three sides, and a new ground surface with the second normal vector, the interpolation vector, and the ground edge line as three sides are generated.

[0231] (Second slope generation / extraction section) As shown in Fig. 38, the second slope generating unit 1616 sets the ground edge line forming the tip of the ground surface as a new section connection line, and generates a new slope from the new section connection line. Specifically, the second slope generating unit 1616 sets both ends of the new section connection line L21 as new nodes P2, and generates new slope lines that are orthogonal to the new section connection line L21 and inclined from each of the new nodes P2. Then, the second slope generating unit 1616 generates a slope whose three sides are the section connection line L21 and the pair of new normal lines.

[0232] When the section connection line L21, which is the base end of the slope, and the section connection line L21, which is the base end of the other slope, are closed (the angle toward the outside of the structure is smaller than 180 degrees), the second slope generation unit 1616 sets the remaining part of the ground edge line and the remaining part of the other ground edge line as new section connection lines L21, respectively, and generates new slopes (one slope, another slope) from each of the new section connection lines. Specifically, as shown in FIG. 44, the second slope generation unit 1616 sets both ends of each new section connection line L21 as new nodes P2, and generates new slope lines from each of the new nodes P2. Then, the second slope generation unit 1616 generates new slopes with the section connection line L21 and a pair of new slope lines as three sides. Then, the extraction unit 1617 extracts an intersection line between the one new slope and the other new slope using a plane extraction method, and further extracts the top surfaces from each of the one new slope and the other new slope.

[0233] On the other hand, if the section connection line L21 which is the base end of the slope and the section connection line L21 which is the base end of another slope are open (the angle toward the outside of the structure is greater than 180 degrees), the second slope generation unit 1616 sets the ground edge line as a new section connection line, as shown in Figure 45, and generates a new slope from the new section connection line.

[0234] When generating a slope having two or more berms, after the second slope generating unit generates the slope, the start point setting unit, the slope generating unit, the deletion unit, the ground surface generating unit, and the second slope generating unit each repeat their operations. As a result, a slope having two or more berms is generated as shown in FIG.

[0235] According to the ground surface data generation device 1A described above, when designing a three-dimensional model of the ground surface including a plurality of structures using parametric modeling, it is possible to easily generate three-dimensional models of the ground surface and slopes between structures, in particular three-dimensional models of slopes with berms.

[0236] Fig. 47 is a flowchart showing a specific flow of a surface generating step S11 when generating a stepped slope, in the earth's surface data generating method executed by the earth's surface data generating device 1A. As shown in Fig. 47, the surface generating step S11A includes steps S111 to S118.

[0237] Step S111 is a slope generation step for generating a slope from the section connection line whose master-slave relationship in the pair connection line is the master. If the elevation of the section connection line whose pair information indicates the master is lower than that of the section connection line whose pair information indicates the slave, in the slope generation step, an upslope going up from the section connection line whose pair information indicates the master is generated. The slope generation may be performed using the above-mentioned ground surface data generation device 1A, or may be performed using another device. Note that in step S111, for section connection lines that are not paired, a surface to be generated from the section connection line may be set in advance, so that a slope or ground surface may be generated from the section connection line. Also, in step S111, a slope (ground surface) once generated may be changed to a ground surface (slope) according to a user operation. Also, there are cases where the pair of section connection lines that form a pair connection line are both master (same rank) in the master-slave relationship. For this reason, in step S111, a berm may be generated regardless of the section connection line from which the slope was generated.

[0238] Step S112 is a start point setting step for setting a plurality of berm start points P3 on the slope, which are starting points for generating berms, based on berm height data acquired in advance. The berm start points P3 may be set using the above-mentioned ground surface data generation device 1A, or may be set using another device. When generating another slope adjacent to the slope and having another berm, the start point setting step calculates the coordinates of the first intersection and the coordinates of the second intersection, calculates the berm start points P3, and generates the division lines, as described above.

[0239] Step S113 is a step of the demarcation line generating unit 1613 for generating demarcation lines L9 connecting the plurality of sub-bench start points P3. As a result, the slope is divided by the demarcation lines L9 into a portion that contacts the section connection line L21 that is the base end of the slope, and a portion that does not contact the section connection line L21. The demarcation lines L9 may be generated using the above-mentioned ground surface data generating device 1A, or may be generated using another device.

[0240] Step S114 is a deletion step in which the part of the slope that is not in contact with the section connection line is deleted from the two parts separated by the division line L9. If the two connected division lines are closed, in step S114, a plane extraction method is used to extract the intersection line between the one slope and the other slope, and the top surface is extracted from each of the one slope and the other slope. Then, the part of each of the extracted top surfaces that is not in contact with the section connection line L21 is deleted from the two parts separated by the division line L9 on each of the extracted top surfaces. The partial deletion of the slope may be performed using the above-mentioned ground surface data generation device 1A or another device.

[0241] Step S115 is a ground surface generation step that generates a ground surface of a small step that is horizontal or inclined less than the slope gradient from the partition line L9 based on the width data so that the ground surface has a width indicated by the width data. When a first partition line that divides the slope and a second partition line that divides the slope are closed, in the ground surface generation step, before generating the ground surface, a first (second) normal vector is obtained, each of which has a node that forms one end of the first (second) partition line and a partition line intersection (node) as its starting point. Then, a new node is placed at the end point of each of the first (second) normal vectors. Then, a first (second) ground edge line is generated with both nodes as its both ends. Then, when the first ground edge line and the second ground edge line intersect, the first ground edge line and the second ground edge line are deleted. Then, a new ground edge line including the first partial edge line and the second partial edge line is generated. Then, a first (second) ground surface passing through the first (second) division line and the first (second) partial connection line is generated.

[0242] On the other hand, when the first section connection line, which is the base end of the slope, and the second section connection line, which is the base end of another slope, are open, in the ground surface generation step, the angle θ between them is obtained before generating the ground surface. Then, the first normal vector of the first section connection line and the second normal vector of the second section connection line are obtained, respectively. Then, linear interpolation is performed between the first normal vector and the second normal vector with a plurality of interpolation vectors. Then, new nodes having the same elevation as the nodes are placed at the end points of each of the interpolation vectors. Then, a ground edge line connecting the new nodes is generated. The ground surface may be generated using the above-mentioned ground surface data generation device 1A, or may be generated using another device.

[0243] Step S116 is a second slope generation step in which the ground edge line forming the tip of the ground surface is set as a new section connection line, and a new slope is generated from the new section connection line. If the section connection line is closed, in the second slope generation step, the remaining part of the ground edge line and the remaining part of the other ground edge line are set as new section connection lines, respectively, and a new slope is generated from each of the section connection lines. Then, using a plane extraction method, the intersection line between the new one slope and the new other slope is extracted, and the top surface is extracted from the new one slope and the new other slope. On the other hand, if the section connection line is open, in the second slope generation step, the ground edge line is set as a new section connection line, and a new slope is generated from the section connection line. The generation of the new slope may be performed using the above-mentioned ground surface data generation device 1A, or may be performed using another device.

[0244] Step S117 is a judgment step for judging whether or not all the berms on the slope have been generated. If it is judged in this judgment step S117 that all the berms have not been generated (step S117: NO), the process returns to step S112. That is, when generating a slope having two or more berms, in the surface generation step, the start point setting step, the deletion step, the ground surface generation step, and the second slope generation step are repeated the same number of times as the number of berms to be generated. In the last second slope generation step, a new slope is generated from the tip of the berm (ground surface) generated in the last ground surface generation step up to the base elevation (the connecting line forming the upper end (lower end) of the structure).

[0245] According to the above-described method for generating ground surface data, when designing a three-dimensional model of the ground surface including a number of structures using parametric modeling, it is possible to easily generate three-dimensional models of the ground surface and slopes between structures, in particular three-dimensional models of slopes with berms.

[0246] [Modifications of the First to Fourth Embodiments] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

[0247] For example, some of the functions of the control blocks of the device according to one embodiment may be performed by a device according to another embodiment, or by a device other than these devices 2.

[0248] At least one of the above-mentioned earth surface data generating programs 141, 142, the design and construction mesh data generating program 241, and the top surface generating program 341 may be recorded on a computer-readable recording medium or multiple recording media, not temporarily. The recording medium may or may not be included in the above-mentioned earth surface data generating device 1 or the design and construction mesh data generating device 2. In the latter case, the above-mentioned programs may be supplied to the above-mentioned earth surface data generating device 1 or the design and construction mesh data generating device 2 via any wired or wireless transmission medium.

[0249] In addition, some or all of the functions of each of the control blocks can be realized by a logic circuit. For example, an integrated circuit in which a logic circuit that functions as each of the control blocks is formed is also included in the scope of the present invention. In addition, the functions of each of the control blocks can be realized by, for example, a quantum computer.

[0250] 〔summary〕 A ground surface data generation method according to a first aspect of the present invention is a ground surface data generation method for generating three-dimensional ground surface data between a plurality of structures, the method including: an acquisition step for acquiring skeleton line data defining a skeleton line consisting of a two-dimensional or three-dimensional oriented polyline or oriented polygon having a starting point and an end point, and discrete elevation data of the structures; a connection line generation step for generating a three-dimensional connection line showing the outer shape of the structures from the skeleton line based on shape data defining the shape of the structures; a shared connection line generation step for generating a single shared connection line by connecting section connection lines separated by a common point that is the intersection point on a vertical projection plane of two of the connection lines; a pairing step for performing a pairing search for a connection line outside the shared connection line from the shared connection line, and setting the section connection lines that are paired as paired lines; and a surface generation step for generating a slope or ground surface from each of the pair connection lines based on pair information indicating a master-slave relationship of each of the section connection lines included in the pair connection lines. and a step of generating a slope having a berm as the slope, the obtaining step further obtains height data and width data of the berm, and the surface generating step includes a slope generating step of generating a slope from the section connection line in which the master-slave relationship in the pair connection lines is the master, a start point setting step of setting a plurality of berm start points that will be starting points for generating berms on the slope based on the height data, a deleting step of generating demarcation lines connecting the plurality of berm start points, a deletion step of deleting one of two parts of the slope separated by the demarcation line that is not in contact with the section connection line, a ground surface generating step of generating a ground surface that is horizontal or inclined less than the gradient of the slope from the demarcation line based on the width data, so that the ground surface has a width indicated by the width data, and a second slope generating step of setting a ground edge line that forms the tip of the ground surface as a new section connection line, and generating a new slope from the new section connection line.

[0251] A ground surface data generating method according to aspect 2 of the present invention may be a method in which, in the above-mentioned aspect 1, when another slope adjacent to the slope and having another berm is generated, the start point setting step calculates coordinates of a first intersection point which is an intersection point of a line between the slope and the other slope and a line segment connecting the row of berm start points set on the slope, calculates coordinates of a second intersection point which is an intersection point of the line of intersection and a line segment connecting the row of berm start points set on the other slope, calculates an average coordinate which is an average of the coordinates of the first intersection point and the coordinates of the second intersection point as a new berm start point, and generates the division line based on the berm start point.

[0252] A ground surface data generating method according to a third aspect of the present invention, in the above-mentioned second aspect, when an angle formed by a first partition line dividing the slope and a second partition line dividing the other slope toward the outside of the structure is less than 180 degrees, in the ground surface generating step, before generating the ground surface, calculates first normal vectors having a node forming one end of the first partition line and a partition line intersection connecting the first partition line and the second partition line as their starting points, which are perpendicular to the first partition line, extend toward the outside of the structure, and have a length equal to the width indicated by the width data, and places new nodes having an elevation equal to the starting point of each first normal vector at the end points of each first normal vector, generates a first ground edge line having both nodes as both ends, and calculates first normal vectors having a node forming one end of the second partition line and the partition line intersection as their starting points, which are perpendicular to the second partition line, extend toward the outside of the structure, and have a length equal to the width indicated by the width data, The method may also include: determining second normal vectors that intersect with each other, extend toward the outside of the structure, and have a length equal to the width indicated by the width data; placing a new node at the end point of each second normal vector, the elevation of which is equal to the starting point of each second normal vector; generating a second ground edge line with both nodes as both ends; when the first ground edge line and the second ground edge line intersect, deleting the portion between the intersection and the connection line from the first ground edge line and the second ground edge line; generating a new ground edge line including the first partial edge line, which is the portion remaining after the deletion, and the node on the second ground edge line that is farther from the first ground edge line, and a second partial edge line that connects the edge line intersection; generating a first ground surface that passes through the first division line and the first partial connection line; and generating a second ground surface that passes through the second section connection line and the second partial connection line.

[0253] A ground surface data generating method according to a fourth aspect of the present invention, in the above-mentioned second aspect, when an angle formed by a first division line dividing the slope and a second division line dividing the other slope toward an outside of the structure is greater than 180 degrees, in the ground surface generating step, before generating the ground surface, calculates a first normal vector having a starting point at a division line intersection connecting the first division line and the second division line, perpendicular to the first division line, extending toward the outside of the structure, and having a length equal to the width indicated by the width data, and calculates a second normal vector having a starting point at the division line intersection, perpendicular to the second division line, extending toward the outside of the structure, and having a length equal to the width indicated by the width data. The method may also include a method of calculating a second normal vector equal to the width indicated by the line, calculating an angle between the first normal vector and the second normal vector, equally dividing the angle between the first normal vector and the second normal vector by an appropriate number, linearly interpolating between the first normal vector and the second normal vector using a plurality of interpolation vectors that start from the node and change direction by the equally divided angle, placing new nodes at the end point of the first normal vector, the end point of the second normal vector, and the end point of each of the interpolation vectors that are equal in elevation to the node, and generating a ground edge line that connects the new nodes.

[0254] A ground surface data generation method according to aspect 5 of the present invention may be a method in which, in the above-mentioned aspect 1, the surface generation step further includes an extraction step of generating another slope adjacent to the slope, using a plane extraction method to extract the uppermost surface, extracting an intersection line between the slope and the other slope, and extracting a portion of the slope located above the other slope and a portion of the other slope located above the slope.

[0255] A ground surface data generation method according to aspect 6 of the present invention may be a method in which, in the above-mentioned aspect 1, when generating a slope having two or more berms, in the acquisition step, height data and width data for each of the two or more berms are further acquired, and in the surface generation step, the start point setting step, the deletion step, the ground surface generation step and the second slope generation step are repeated the same number of times as the number of berms to be generated, and in the final second slope generation step, the new slope is generated up to the base elevation.

[0256] A ground surface data generation method according to aspect 7 of the present invention may be a method in which, in aspect 1 above, when the elevation of the section connecting line indicated by the pair information as master is lower than that of the section connecting line indicated by the pair information as slave, in the slope generation step, an upslope ascending from the section connecting line indicated by the pair information as master is generated.

[0257] A ground surface data generation method according to aspect 8 of the present invention may be a method in which, in the above aspect 1, the pairing search is performed using at least one of a two-dimensional inscribed circle method, a three-dimensional inscribed sphere method, and a three-dimensional skewer and ball method for searching for other shared connection lines from ground surface lines or normal lines extended from the nodes on a switching candidate line generated from a plurality of nodes constituting the shared connection line.

[0258] A ground surface data generation program according to a ninth aspect of the present invention is a ground surface data generation program that causes a computer to generate three-dimensional ground surface data between a plurality of structures, and includes the following steps: an acquisition step in which the computer acquires skeleton line data defining a skeleton line consisting of a two-dimensional or three-dimensional oriented polyline or oriented polygon having a starting point and an end point, and discrete elevation data of the structures; a connection line generation step in which a three-dimensional connection line showing the outline of the structures is generated from the skeleton line based on shape data defining the shape of the structures; a shared connection line generation step in which section connection lines separated by a common point that is the intersection point on a vertical projection plane of two of the connection lines are connected to generate a single shared connection line; a pairing search step in which the shared connection line is searched for a connection line outside the shared connection line, and the section connection lines that are paired are treated as paired lines; and a pairing step in which the computer acquires a paired connection line from each of the pair connection lines based on pair information indicating a master-slave relationship of each of the section connection lines contained in the pair connection lines. and a surface generating step of generating a slope or a ground surface. In the case where a slope having a berm is to be generated as the slope, the obtaining step further obtains height data and width data of the berm, and the surface generating step executes the following steps: a slope generating step of generating a slope from the section connection line whose master-slave relationship in the pair connection line is the master; a start point setting step of setting a plurality of berm start points on the slope as starting points for generating berms based on the height data; a deletion step of dividing the slope with a division line connecting the plurality of berm start points and deleting one of the two divided parts that is not in contact with the section connection line; a ground surface generating step of generating a ground surface that is horizontal or inclined less than the gradient of the slope from the division line based on the width data so that the width is indicated by the width data; and a second slope generating step of setting a ground edge line that forms the tip of the ground surface as a new section connection line and generating a new slope from the new section connection line.

[0259] A ground surface data generating device according to a tenth aspect of the present invention is a ground surface data generating device that generates three-dimensional ground surface data between a plurality of structures, and includes an acquisition unit that acquires skeleton line data defining a skeleton line consisting of a two-dimensional or three-dimensional oriented polyline or oriented polygon having a starting point and an end point, and discrete elevation data of the structures, a connection line generation unit that generates a three-dimensional connection line showing the outline of the structures from the skeleton line based on shape data defining the shape of the structures, a shared connection line generation unit that connects section connection lines separated by a common point that is the intersection point on a vertical projection plane of two of the connection lines to generate a single shared connection line, a pairing unit that executes a pairing search that searches for connection lines outside the shared connection line from the shared connection line, and sets the section connection lines that are paired as paired lines, and a pairing unit that calculates a slope or ground surface from each of the pair connection lines based on pair information indicating a master-slave relationship of each of the section connection lines included in the pair connection lines. and a surface generation unit that generates a slope having a berm as the slope, and in the case of generating a slope having a berm as the slope, the acquisition unit further acquires height data and width data of the berm, and the surface generation unit comprises: a slope generation unit that generates a slope from the section connection line whose master-slave relationship in the pair connection lines is the master; a start point setting unit that sets a plurality of berm start points on the slope based on the height data as starting points for generating berms; a division line generation unit that generates division lines connecting the plurality of berm start points; a deletion unit that deletes one of two parts of the slope separated by the division line that is not in contact with the section connection line; a ground surface generation unit that generates a ground surface that is horizontal or inclined less than the gradient of the slope from the division line based on the width data, so that the width is indicated by the width data; and a second slope generation unit that sets a ground edge line that forms the tip of the ground surface as a new section connection line and generates a new slope from the new section connection line. [Explanation of symbols]

[0260] 3…Top surface generation device 9…Mesh division and joining device 35, 36…Control section 351…Acquisition Department 352…Slope generation section 353...Extraction part 354, 366...Output processing section 361: Surface mesh acquisition section 362…exchange generator 363…Mesh division section 364…Nullification section 365…Mesh joint 34,37...Storage section 341…Ground surface generation program 371...Mesh division and joining program 11...Input section 13...Output section

Claims

1. A method for generating three-dimensional ground surface data between a plurality of structures, comprising the steps of: An acquisition step of acquiring skeleton line data defining a skeleton line consisting of a two-dimensional or three-dimensional oriented polyline or oriented polygon having a start point and an end point, and discrete elevation data of the structure; a connection line generating step of generating, from the skeleton line, three-dimensional connection lines that indicate the outer shape of the structure, based on shape data that defines the shape of the structure; a shared connection line generating step of generating a single shared connection line by connecting section connection lines separated by a common point that is an intersection point on a vertical projection plane of the two connection lines; a pairing step of performing a pairing search for a connection line located outside the shared connection line from the shared connection line, and setting the section connection lines that are paired as paired connection lines; a surface generating step of generating a slope or a ground surface from each of the paired connecting lines based on pair information indicating a master-slave relationship of each of the section connecting lines included in the paired connecting lines; Including, When a slope having a berm is to be generated as the slope, In the acquiring step, height data and width data of the step are further acquired, The surface generation step includes: a slope generating step of generating a slope from the section connection line in which the master-slave relationship is the master in the pair connection line; a start point setting step of setting a plurality of berm start points on the slope based on the height data, the berm start points being used as start points for generating berms; a demarcation line generating step of generating demarcation lines connecting the plurality of bench start points; a deletion step of deleting one of the two portions of the slope separated by the partition line that is not in contact with the section connection line; A ground surface generating step of generating a ground surface that is horizontal or inclined less than the slope of the slope from the division line based on the width data so that the ground surface has a width indicated by the width data; A second slope generation step of setting the ground edge line forming the tip of the ground surface as a new section connection line and generating a new slope from the new section connection line; Including, Surface data generation method.

2. In the case of generating another slope adjacent to the slope and having another berm, in the starting point setting step, calculating coordinates of a first intersection point which is an intersection point between an intersection line between the slope and the other slope and a line segment connecting the row of berm start points set on the slope; calculating coordinates of a second intersection point, which is an intersection point between the intersection line and a line segment connecting the row of berm start points set on the other slope; calculating an average coordinate, which is an average of the coordinates of the first intersection point and the coordinates of the second intersection point, as a new step start point; generating the lane markings based on the berm start points; The method for generating earth surface data according to claim 1 .

3. When an angle between a first dividing line dividing the slope and a second dividing line dividing the other slope toward the outside of the structure is smaller than 180 degrees, in the ground surface generation step, before generating the ground surface, A first normal vector is obtained, the first normal vector having a starting point at a node forming one end of the first demarcation line and a demarcation line intersection point connecting the first demarcation line and the second demarcation line, the first normal vector is perpendicular to the first demarcation line, extends toward the outside of the structure, and has a length equal to the width indicated by the width data; A new node having an elevation equal to that of the start point of each of the first normal vectors is placed at the end point of each of the first normal vectors; A first ground edge line is generated with both nodes as both ends; determining second normal vectors each having a starting point at a node that forms one end of the second demarcation line and a starting point at the demarcation line intersection, each perpendicular to the second demarcation line, extending toward the outside of the structure, and having a length equal to the width indicated by the width data; A new node having an elevation equal to that of the start point of each second normal vector is placed at the end point of each second normal vector; A second ground edge line is generated with both nodes as its ends; When the first ground edge line and the second ground edge line intersect, From the first ground edge line and the second ground edge line, a portion between the edge line intersection point, which is an intersection point between line segments formed by projecting the first ground edge line and the second ground edge line onto a horizontal plane, and a connection line is deleted; A new ground edge line is generated including a first partial edge line that is a portion remaining after the deletion, and a second partial edge line that connects the node farther from the first ground edge line in the second ground edge line and the edge line intersection point; Generate a first ground surface passing through the first lot line and the first partial edge line; generating a second ground surface passing through the second lot line and the second partial edge line; The method for generating earth surface data according to claim 2 .

4. When an angle between a first dividing line dividing the slope and a second dividing line dividing the other slope toward the outside of the structure is greater than 180 degrees, in the ground surface generation step, before generating the ground surface, A first normal vector is obtained, the first normal vector having a starting point at a partition line intersection connecting the first partition line and the second partition line, perpendicular to the first partition line, extending toward the outside of the structure, and having a length equal to the width indicated by the width data; A second normal vector is obtained that has the intersection of the lane lines as a starting point, is perpendicular to the second lane line, extends toward the outside of the structure, and has a length equal to the width indicated by the width data; determining an angle between the first normal vector and the second normal vector; an angle between the first normal vector and the second normal vector is equally divided by an appropriate number, and linearly interpolating between the first normal vector and the second normal vector with a plurality of interpolation vectors whose directions change by the equally divided angle, starting from the intersection of the partition lines; A new node having an elevation equal to that of the partition line intersection is disposed at an end point of the first normal vector, an end point of the second normal vector, and an end point of the interpolation vector, respectively; Generate ground edge lines connecting the new nodes. The method for generating earth surface data according to claim 2 .

5. The surface generation step includes: The method further includes an extraction step of: generating another slope adjacent to the slope, and then extracting an intersection line between the slope and the other slope using a plane extraction method that extracts an uppermost face, and extracting a portion of the slope located above the other slope and a portion of the other slope located above the slope, The method for generating earth surface data according to claim 1 .

6. When generating the slope having two or more berms, In the acquiring step, height data and width data of each of the two or more steps are further acquired; In the surface generating step, the start point setting step, the deletion step, the ground surface generating step, and the second slope generating step are repeated the same number of times as the number of berms to be generated; In the final second slope generation step, the new slope is generated up to a base elevation. The method for generating earth surface data according to claim 1 .

7. When the elevation of the section connection line indicated by the pair information as being main is lower than that of the section connection line indicated by the pair information as being secondary, an upslope ascending from the section connection line indicated by the pair information as being main is generated in the slope generation step. The method for generating earth surface data according to claim 1 .

8. The pairing search is performed on a switching candidate line generated from a plurality of nodes constituting the shared connection line by using at least one of a two-dimensional inscribed circle method, a three-dimensional inscribed sphere method, and a three-dimensional skewer-and-ball method for searching for another shared connection line from a ground surface line or a normal line extended from the node. The method for generating earth surface data according to claim 1 .

9. A ground surface data generation program for causing a computer to generate three-dimensional ground surface data between a plurality of structures, comprising: The computer includes: An acquisition step of acquiring skeleton line data defining a skeleton line consisting of a two-dimensional or three-dimensional oriented polyline or oriented polygon having a start point and an end point, and discrete elevation data of the structure; a connection line generating step of generating, from the skeleton line, three-dimensional connection lines that indicate the outer shape of the structure, based on shape data that defines the shape of the structure; a shared connection line generating step of generating a single shared connection line by connecting section connection lines separated by a common point that is an intersection point on a vertical projection plane of the two connection lines; a pairing step of performing a pairing search for a connection line located outside the shared connection line from the shared connection line, and setting the section connection lines that are paired as paired connection lines; a surface generating step of generating a slope or a ground surface from each of the paired connecting lines based on pair information indicating a master-slave relationship of each of the section connecting lines included in the paired connecting lines; Run the command, When a slope having a berm is to be generated as the slope, In the acquiring step, height data and width data of the step are further acquired, In the surface generation step, a slope generating step of generating a slope from the section connection line in which the master-slave relationship is the master in the pair connection line; a start point setting step of setting a plurality of berm start points on the slope based on the height data, the berm start points being used as start points for generating berms; a deleting step of dividing the slope by a dividing line connecting the start points of the plurality of berms, and deleting one of the two divided portions that is not in contact with the section connection line; A ground surface generating step of generating a ground surface that is horizontal or inclined less than the slope of the slope from the division line based on the width data so that the ground surface has a width indicated by the width data; A second slope generation step of setting the ground edge line forming the tip of the ground surface as a new section connection line and generating a new slope from the new section connection line; Execute the A program for generating earth surface data.

10. A ground surface data generating device that generates three-dimensional ground surface data between a plurality of structures, comprising: an acquisition unit that acquires skeleton line data that defines a skeleton line consisting of a two-dimensional or three-dimensional oriented polyline or oriented polygon having a start point and an end point, and discrete elevation data of the structure; a connection line generating unit that generates, based on shape data that defines a shape of the structure, three-dimensional connection lines that indicate an outer shape of the structure from the skeleton lines; a shared connection line generating unit that generates a single shared connection line by connecting section connection lines separated by a common point that is an intersection point of the two connection lines on a vertical projection plane; a pairing unit that executes a pairing search for a connection line located outside the shared connection line from the shared connection line, and sets the section connection lines that are paired with each other as a pair connection line; a surface generating unit that generates a slope or a ground surface from each of the paired connecting lines based on pair information indicating a master-slave relationship of each of the section connecting lines included in the paired connecting lines; Equipped with When a slope having a berm is to be generated as the slope, The acquisition unit further acquires height data and width data of the bench, The surface generation unit a slope generating unit that generates a slope from the section connection line in which the master-slave relationship is a master in the pair connection lines; a start point setting unit that sets a plurality of berm start points on the slope based on the height data, the berm start points being used as start points for generating berms; a demarcation line generating unit for generating demarcation lines connecting the plurality of bench start points; A deletion unit that deletes one of the two portions of the slope that is separated by the partition line and does not contact the section connection line; A ground surface generating unit that generates a ground surface that is horizontal or inclined less than the slope of the slope from the division line based on the width data so that the ground surface has a width indicated by the width data; A second slope generating unit that sets the ground edge line that forms the tip of the ground surface as a new section connection line and generates a new slope from the new section connection line; Equipped with Earth surface data generator.

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