Sun shadow map creation system, sun shadow map creation method, and sun shadow map creation program

Abstract

To provide a sun shadow map creation system, a sun shadow map creation method, and a sun shadow map creation program that can display a sun shadow with high accuracy on a two- or more-dimensional map.SOLUTION: A sun shadow map creation system has a database that stores ground surface three-dimensional data including information on a three-dimensional shape of a ground surface, building three-dimensional data including information on a three-dimensional shape of a building, and map data. A control unit extracts the shape of a rooftop 31 of a structure, creates a plurality of rays 10 in the direction of sunlight vector V at a specific time, with a back face 30A of the structure 30 as a starting point, and a ground surface collision point 12A where the rays 10 collide with the ground surface 40 or a structure collision point 12B where the rays first collide with a front face of the structure 30 as an end point, and couples the rays to each other to generate sun shadow data. The sun shadow map creation system displays the sun shadow data and map data in an overlapping manner to create a sun shadow map.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a shadow map creation system, a shadow map creation method, and a shadow map creation program, and in particular to a shadow map creation system, a shadow map creation method, and a shadow map creation program that superimpose and display map data and shadow data created by structures, topography, etc. [Background technology]

[0002] With the recent rise in summer temperatures, people want to walk in the shade as much as possible when walking around town. Everyone carries a mobile device such as a smartphone, and they often travel to their destination with a map application running. However, simply looking at a publicly available 2D map app makes it difficult to determine which of several routes offers the most shade.

[0003] A conventional shadow simulation system is one that simulates the shadow conditions when solar panels are installed on a building to be constructed on a specific construction site (Patent Document 1). The shadow simulation system reads 2D map data and floor height settings, and then uses a 3D conversion function to create a 3D representation of the specific area. Additional corrections are made to the building exterior and surrounding additional structures, and CAD software is used to perform simulation calculations of solar panels on the balconies of each unit on the building at the construction site.

[0004] Another shadow simulation system can simulate the impact of shadows cast by a building on which construction is planned (Patent Document 2). By inputting customer information, the shadow simulation system automatically generates the three-dimensional shapes of buildings surrounding the planned construction site and the shadows cast by these surrounding buildings based on map information. This makes it possible to verify the impact of shadows cast by buildings surrounding the customer's building. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-153849 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-265833 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the shadow simulation systems described in Patent Documents 1 and 2 are systems that simulate the shadows of buildings on a planned construction site, and therefore cannot simulate the shadows cast on roads or the ground by multiple buildings within a specific area. Furthermore, although the shadows are created using a 3D CAD system, the detailed method for creating them is not clearly stated.

[0007] Furthermore, there was a demand for a map application for mobile devices that would meet the needs of customers who want to walk in the shade as much as possible when walking around town in the summer, or who want to go out during times when there is a lot of shade. However, it was difficult to extend the technology of Patent Documents 1 and 2 to two-dimensional maps.

[0008] Therefore, an object of the present invention is to provide a shadow map creation system, a shadow map creation method, and a shadow map creation program that can display shadows with high accuracy on a two-dimensional map. [Means for solving the problem]

[0009] In order to solve the above problems, the present invention provides a shadow map creation system comprising: a database in which map data and shadow generation 3D data including information on the three-dimensional shape of a shadow generating body are stored; a shape extraction unit that extracts the shape of the shadow generating body from the shadow generation 3D data; a ray generation unit that creates a plurality of rays in the sunlight vector direction at a specific time, with the shadow generating body as the starting point and the point where the ray hits another shadow generating body or the ground as the nearest point of impact as the end point; a shadow data creation unit that creates shadow data by combining a plurality of the rays; and a shadow map creation unit that displays the shadow data and the map data in an overlapping manner.

[0010] Furthermore, it is preferable that the shadow generation 3D data includes structural 3D data relating to a structure and ground 3D data relating to the ground, and that the shape extraction unit extracts, from the shape data of the structure based on the structural 3D data, the surface onto which sunlight enters from the sunlight vector and the back surface from which the sunlight exits the structure if it is assumed that the sunlight passes through the structure, and that the ray generation unit generates the ray with the structure as the starting point and the collision point where the ray collides with the ground or the surface of the structure in the shortest distance as the end point, and that any rays that collide with the back surface of the structure are not generated among the generated rays.

[0011] Furthermore, it is preferable that the shadow generation 3D data includes structural 3D data relating to a structure and ground 3D data relating to the ground, and that the shape extraction unit extracts, from the ground shape data based on the ground 3D data, a surface onto which sunlight enters from the sunlight vector and a back surface from which the sunlight exits the ground if it is assumed that the sunlight passes through the ground, and that the ray generation unit generates the ray with the back surface of the ground as a starting point and the point of impact where the ray hits the ground or the structure in the shortest distance as an end point, and that any rays that hit the back surface of the ground are not generated among the generated rays.

[0012] Furthermore, it is preferable that the shadow generation 3D data includes additional structure 3D data relating to an additional structure whose shape has been specified by a user, and that the shape extraction unit extracts, from the shape data of the additional structure based on the additional structure 3D data, the surface onto which sunlight enters from the sunlight vector and the back surface from which the sunlight exits the additional structure if it is assumed that the sunlight passes through the ground, and that the ray generation unit generates the ray with the back surface of the additional structure as its starting point and the point of impact where the ray hits the ground or the structure in the shortest distance as its end point, and that the shadow data creation unit stores the shadow data created by combining the rays of the additional structure in the database.

[0013] In another aspect of the present invention, there is provided a shadow map creation method comprising the steps of: preparing a database in which map data and shadow generation 3D data including information on the three-dimensional shape of a shadow generating body are stored; extracting the shape of the shadow generating body from the shadow generation 3D data; creating a plurality of rays in the sunlight vector direction at a specific time, with the outline of the shadow generating body as the starting point and the point of impact where the ray strikes another shadow generating body or the ground as the nearest point of impact; creating shadow data by combining the plurality of rays; and displaying the shadow data and the map data in an overlaid state.

[0014] In another aspect of the present invention, there is provided a shadow map creation program that causes an information processing terminal having a database in which structure 3D data including information on the three-dimensional shape of a shadow generating body and map data is stored to execute the following steps: extracting the shape of the shadow generating body from the shadow generation 3D data; creating a plurality of rays in the sunlight vector direction at a specific time, with the outline of the shadow generating body as the starting point and the point where the ray hits another shadow generating body or the ground as the nearest point of impact as the end point; creating shadow data by combining the plurality of rays; and superimposing and displaying the shadow data and the map data. [Effects of the Invention]

[0015] With this configuration, shadows are created by combining rays in the direction of the sunlight vector, starting from the rooftop and ending at the point where they collide with the ground or a structure. This allows for highly accurate representation of shadows cast by structures. Furthermore, because the rooftop and ground, which are the collision points, are set based on 3D data, the location of the shadow can be represented with high accuracy. This allows for the creation of a shadow map that meets users' needs, such as searching for a route that will allow them to walk in the shade as much as possible during the heat of summer. Furthermore, users can refer to the shadow map to plan their departure time and route to their destination in advance. Furthermore, because the shadow map is created based on 3D ground data and 3D structure data, it is possible to understand the shadow shape of rooftops and walls, taking into account the shadows cast by surrounding structures. This allows users to check the sunlight exposure when considering solar panel installation locations or searching for real estate. In particular, given the recent rise in summer temperatures and rising electricity rates, it is expected that there will be a growing demand for properties with shade. Shadow maps created by the shadow map creation system can meet users' needs for highly accurate information on the location of shadows.

[0016] With this configuration, the back surface extracted by the shape extraction unit is used as the starting point of the ray and the collision point with the structure or the ground is used as the end point, making it possible to represent shadows with multiple rays with high accuracy. This makes it possible to display shadows generated by structures and the ground with high accuracy on a map. Furthermore, by generating rays that collide with the front surface of a structure and not generating rays that collide with the back surface of the structure, it is possible to remove rays within the structure. This prevents shadows from being generated within the structure and makes it possible to generate a shadow map with high accuracy.

[0017] With this configuration, a shadow is created by combining rays in the direction of the sunlight vector, with the starting point being the roof of the additional structure and the ending point being the point of impact with the ground or the structure, so the shadow cast by the structure can be expressed with high accuracy.In addition, since any shape can be set, it is possible to simulate the impact of the shadow cast by a building to be constructed on surrounding structures.

[0018] With this configuration, the back surface extracted by the shape extraction unit is the starting point of the ray and the collision point with the structure or the ground is the end point, so that shadows can be represented with high accuracy even for structures other than buildings such as bridges and steel towers that cast shadows. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a schematic diagram of a shadow map creation system according to the present invention. [Figure 2] 1 is a block diagram of a shadow map creation system according to the present invention. [Figure 3] FIG. 2 is a data flow diagram of the shadow map creation system of the present invention. [Figure 4] 10 is a flowchart showing offline shadow map creation by the shadow map creation system of the present invention. [Figure 5] 10 is a flowchart of the online shadow map display of the shadow map creation system of the present invention. [Figure 6] A three-dimensional map drawn with rays from the roof of a building, which is a structure used in the shadow map creation system of the present invention. [Figure 7] A two-dimensional partial cross-sectional view of a ray drawn from the roof of a building, which is a structure of the shadow map creation system of the present invention. [Figure 8] A two-dimensional map drawn with rays from the roof of a building, which is a structure used in the shadow map creation system of the present invention. [Figure 9] 10 is a flowchart of the shadow map creation system of the present invention for creating 2D shadow data. [Figure 10] 10A and 10B are diagrams for explaining normalization of ray collision points in the shadow map creation system of the present invention. [Figure 11]FIG. 2 is a partial enlarged view of the rooftop and ray of the shadow map creation system of the present invention, illustrating the vertex addition process. [Figure 12] A two-dimensional map of shadows generated by combining rays from the shadow map creation system of the present invention. [Figure 13] 1 shows a shadow map created by the shadow map creation system of the present invention. [Figure 14] 10 is a flowchart of a structure addition process of the shadow map creation system of the present invention. [Figure 15] 10 is a flowchart of the shadow map display when a structure is added to the shadow map creation system of the present invention. [Figure 16] A shadow map when a structure is added to the shadow map creation system of the present invention. [Figure 17] A 3D map drawn using rays from the ground surface by the shadow map creation system of the present invention. [Figure 18] A two-dimensional map drawn by rays from the ground surface using the shadow map creation system of the present invention. [Figure 19] 1 is a shadow map showing the shadows generated by the ground surface of the shadow map generation system of the present invention. [Figure 20] A 3D map drawn with rays from Tokyo Tower, a structure included in the shadow map creation system of the present invention. [Figure 21] A two-dimensional map drawn with rays from Tokyo Tower, a structure included in the shadow map creation system of the present invention. [Figure 22] 1 is a shadow map showing the shadow generated by Tokyo Tower, a structure included in the shadow map creation system of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] The shadow map creation system 1 according to the present invention will be described with reference to Figures 1 to 22. The shadow map creation system 1 creates a shadow map at a specific time offline, and provides a shadow map for a specified year, month, day, hour, minute, and second in response to a request from a user online.

[0021] 1, the shadow map creation system 1 includes a server 2, an administrator terminal 3, and at least one user terminal 4, which are communicably connected via a network 5. The server 2 and the administrator terminal 3 are computers including a processor, and are examples of information processing terminals that are hardware configurations for realizing the present invention.

[0022] As shown in Fig. 2, the server 2 mainly includes a control unit 21 and a storage unit 22. The control unit 21 is a CPU (Central Processing Unit) that runs an OS (Operating System) stored in the storage unit 22 to control the entire server 2. The control unit 21 reads and deploys various programs stored in the storage unit 22. The control unit 21 may be both a CPU and a GPU (Graphic Processing Unit). By incorporating a GPU, processing is parallelized, enabling high-speed calculation processing and enabling a response to a request from the user terminal 4 in a short time.

[0023] The storage unit 22 is composed of an HDD (Hard Disk Drive), ROM (Read Only Memory), and RAM (Random Access Memory). The storage unit 22 may include recording media such as an optical disk, a flexible disk, a magneto-optical disk, an external hard disk, or a semiconductor memory. The storage unit 22 stores various programs for operating the shadow map creation system 1. The programs may be downloaded from another information processing terminal via the network 5. The storage unit 22 is an example of a database of the present invention.

[0024] The storage unit 22 stores ground 3D data 23, which is three-dimensional ground data, structure 3D data 24, which is three-dimensional structure data, rooftop shape 3D data 25, which is shape data of the rooftop of the structure, two-dimensional shadow 2D data 26, which represents the shape of the shadow, and map 2D data 27, which is two-dimensional map data. In this embodiment, PLATEAU, which is released as open data by the Ministry of Land, Infrastructure, Transport and Tourism, is used as the ground 3D data 23 and the structure 3D data 24, but this is not limiting and any other three-dimensional map data can be used. The map 3D data 23, structure 3D data 24, and rooftop shape 3D data 25 are examples of shadow generation 3D data of the present invention, and the shadow 2D data 26 is an example of shadow data of the present invention.

[0025] The structural 3D data 24 represents the unevenness of structures, and the structural data in Plateau's CityGML data is triangulated to create a data mesh and a 3D TIN (Triangulated Irregular Network). In Plateau's ground 3D data 23, the ground data is represented as TIN data, so no conversion is required. However, when using other map data, TIN processing using triangulation is performed in the same way as for structures. The term "structures" here is not limited to buildings and houses, but also includes symbols such as bridges, overpasses, viaducts, overpasses, footbridges, utility poles, steel towers, Tokyo Tower (registered trademark), Tokyo Skytree (registered trademark), trees, five-story pagodas, temples, and gas holders.

[0026] The administrator terminal 3 is a terminal operated by an administrator of the shadow map creation system 1, and performs various system settings and condition changes. The user terminal 4 is operated by a user of the shadow map creation system 1 to connect to the server 2 via a web browser and display the shadow map 20 shown in Fig. 13 on the display 41. The user terminal 4 may be connected to the server 2 and display the shadow map 20 on the display 41 by installing a dedicated application.

[0027] <2D shadow data creation flow> Next, a flow for creating the shadow 2D data 26 of the shadow map creating system 1 will be described with reference to FIGS.

[0028] The control unit 21 reads the ground 3D data 23 and structure 3D data 24 from the memory unit 22 and expands them in RAM (S1 and S2 in FIGS. 3 and 4). Next, rooftop shape 3D data is created from the structure 3D data 24 (S3). Specifically, the control unit 21 extracts only the rooftop shape of the structure from the plateau's CityGML data as a three-dimensional shape and stores it in the memory unit 22 as three-dimensional rooftop shape 3D data 25.

[0029] Since the rooftop shape 3D data 25 is three-dimensional data, it can represent not only flat shapes such as the roof of a building, but also sloped roof shapes such as gable roofs, hip roofs, square roofs, and bevel roofs as three-dimensional shape data.

[0030] The control unit 21 calculates the sunlight vector V at a specific time using a specified calculation formula (S4). The sunlight vector V here is a unit vector representing the position of the center of the sun from the viewpoint in a horizontal coordinate system. The sunlight vector V is calculated as a three-dimensional vector based on parameters of solar declination, latitude, and hour angle using a known calculation formula with Japan Standard Time (JST) as the reference.

[0031] As shown in FIG. 6, the control unit 21 creates a starting point 11 for drawing a ray 10 from the rooftop 31 of the structure 30 in the rooftop shape 3D data 25 in the direction of the sunlight vector V calculated in S4 (S5).

[0032] Specifically, all vertices of the rooftop 31 are extracted, and from one vertex to the next, 10cmThe start points 11 (x, y, z) of the rays 10 are created at intervals D. As shown in the enlarged view of FIG. 8, the interval D between the rays 10 is 10 cm, so the intervals between the start points 11 of the rays 10 on the rooftop 31 are not uniform. The control unit 21 creates start points 11 on the edges connecting all vertices of the rooftop 31. The rooftops 31 extracted by the control unit 21 are not limited to those horizontal to the ground, and all TINs in the rooftop shape 3D data 25 are extracted. Note that FIG. 6 shows the state after the process of deleting rays 10 within the structure itself (S11), which will be described later, has been performed. Therefore, in the two-dimensional representation, rays 10 are drawn only from the edges of the rooftop 31 that are located downstream of the sunlight vector V. The intervals between the start points 11 of the rays 10 are not limited to 10 cm and can be set arbitrarily depending on the accuracy of the shadow map 20 and the processing capacity of the server 2.

[0033] Based on the structure 3D data 24 and the rooftop shape 3D data 25, the control unit 21 defines, for all TINs of the structure 30 and rooftop 31, either the front surface 30A, which is the surface onto which the sunlight vector V enters, or the back surface 30B, from which sunlight exits when the sunlight vector V is assumed to pass through the structure 30. Specifically, by taking the cross product of the normal vector of each TIN and the sunlight vector V, the front surface 30A or the back surface 30B is defined as shown in FIG. 6. The process by which the control unit 21 creates the rooftop shape 3D data 25 and defines the front surface 30A or the back surface 30B for all TINs is an example of the shape extraction unit of the present invention.

[0034] The control unit 21 draws a ray 10 from the starting point 11 in the direction of the sunlight vector V, and calculates a collision point 12 at the shortest distance where the ray 10 collides with either the surface 30A of the other structure 30 (other structure) or the ground 40 (S6). The polygons in FIG. 8 represent the unevenness of the ground 40, and the outlined shapes represent the rooftop 31. As shown in FIGS. 6 and 8, the control unit 21 draws the ray 10 so as to connect the starting point 11 defined on the rooftop 31 with multiple ground collision points 12A where the ray 10 collides with the ground 40, and also draws the ray 10 so as to connect the starting point 11 with the structure collision point 12B where the ray 10 collides with the surface 30A of the other structure 30. As shown in FIG. 7(b), which is a cross section taken along line aa in FIG. 7(a), ray 10 is drawn from starting point 11 on rooftop 31 of structure 30 to ground collision point 12A where ray 10 collides with ground 40. However, as shown by the dotted line, ray 10 is further extended to reach structure collision point 12B, which is collision point 12 with surface 30A of another structure 30. Extending ray 10 that terminates at ground collision point 12A will result in collision with surface 30A of another structure 30, as shown by the dotted line. However, since the point of collision with either surface 30A of another structure 30 or ground 40 at the shortest distance is defined as collision point 12, ray 10 terminates at ground collision point 12A, which is collision point 12 with ground 40, and the dotted line portion is not drawn. The process by which control unit 21 draws ray 10 from starting point 11 to collision point 12 is an example of a ray generation unit of the present invention.

[0035] The control unit 21 creates two-dimensional shadow 2D data 26 by combining rays 10 from the rooftop 31 (S7). The flow of creating the shadow 2D data 26 will be described with reference to Figs. 8 to 12. In this embodiment, because a shadow cannot be accurately represented by simply combining rays 10, a vertex addition process shown in Fig. 11 is performed to create highly accurate shadow 2D data 26. The process by which the control unit 21 creates the shadow 2D data 26 by combining rays 10 is an example of the shadow data creation unit of the present invention.

[0036] The control unit 21 does not process the ray 10 within the area of the rooftop 31 of the structure 30 (S11). The control unit 21 does not process the ray 10 within the rooftop 31 by determining whether the ray 10 collides with the back surface 30B of the structure 30 itself. In other words, as shown by the dotted virtual ray 10A in FIG. 6, the virtual ray 10A defined with the start point 11 being the outline located upstream of the solar vector V of the rooftop 31 is the ray 10 that collides with the back surface 30B of the structure 30 itself, and is therefore not subject to processing. In other words, the start point 11 is defined only on the side of the rooftop 31 that is located downstream in the direction of the solar vector V. In other words, when a straight line in the direction of the solar vector V that intersects with the rooftop 31 is drawn, the start point 11 is not defined at the point that touches the rooftop 31 at the shortest point, but the start point 11 is defined at the point that passes through the area of the rooftop 31 and exits the rooftop 31.

[0037] Ray 10 is drawn using all edges connecting all vertices of rooftop 31 as starting points 11, and therefore is also drawn in the area within rooftop 31. However, rooftop 31 is always in the sun, so rays 10 within the rooftop 31 area must be deleted, as shown in FIG. 8. In this embodiment, a front surface 30A and a back surface 30B are defined for all TINs that make up structure 30, and rays 10 that collide with the back surface 30B of the structure 30 itself are excluded from processing, thereby preventing rays 10 from being drawn on rooftop 31. This makes it possible to draw rays 10 only from the back surface 30B of the structure 30, out of the front surface 30A and back surface 30B of the structure 30.

[0038] The control unit 21 determines whether the ray 10 is colliding with the surface 30A of the own structure 30 (the own structure) from the rooftop 31 (S12). In S6, the collision point 12 with the surface 30A of the other structure 30 is set as the structure collision point 12B, so the ray 10 penetrates the own structure 30. As shown in the first area A of FIG. 8, if it is determined that the ray 10 is colliding with the surface 30A of the own structure 30 from the rooftop 31 (S12: YES), the control unit 21 draws the ray 10 by connecting the starting point 11 and the collision point 12 where the ray 10 collided with the own structure 30. Furthermore, the control unit 21 connects the starting points 11 of the multiple rays 10 colliding with the own structure 30 with adjacent starting points 11, and joins the collision points 12 with adjacent collision points 12 to create polygons (S13). As a result, a large number of polygons are generated in which rays 10 are joined with adjacent rays 10, as shown in the first area A of FIG. 8. If it is determined that the ray 10 has not collided from the rooftop 31 with the surface 30A of the structure 30 (S12: NO), a polygon is created by connecting the starting point 11 with the ground collision point 12A or the structure collision point 12B (S14). This generates a large number of polygons in which rays 10 are joined with adjacent rays 10, as shown in the second region B of Fig. 8.

[0039] The control unit 21 determines whether the distance between the end ray 10 on the edge of the rooftop 31 and the vertex 31A of the rooftop 31 is less than 10 cm, which is the interval D between the rays 10 (S15). In other words, it determines whether the vertex 31A of the rooftop 31 exists between the rays 10 drawn every 10 cm. As shown in FIGS. 11(a) and 11(b), the vertex 31A of the rooftop 31 exists between the ray 10 drawn at the interval D of 10 cm and the dotted virtual ray 10A that is separated from the end ray 10 by the interval D of 10 cm, which does not actually exist. Therefore, the diagonal virtual shadow area 13A that would normally be shaded is not surrounded by the ray 10 and is in the sun. In other words, if the vertex 31A is located between the end ray 10 and the dotted virtual ray 10A, a shadow will not be cast from the vertex 31A, but will be cast from a position slightly inward from the vertex 31A. In this embodiment, to avoid such a situation, the starting point 11 of the ray 10 is created at the vertex 31A by the vertex addition process.

[0040] If the distance between the terminal ray 10 on the edge of the rooftop 31 and the vertex 31A of the rooftop 31 is less than 10 cm (S15: YES), a vertex addition process is performed to add the vertex 31A to the shadow area 13 (S16). Specifically, in the case of FIG. 11(a), the ray 10 is drawn with the vertex 31A as the starting point 11, and the collision point 12 is set. In the case of FIG. 11(b), the starting point 11 or the collision point 12 is set at the vertex 31A. This allows the provisional shadow area 13A to be surrounded by the ray 10, so that the provisional shadow area 13A is incorporated into the shadow area 13 described below, allowing the shadow of the structure 30 to be represented with high accuracy.

[0041] If the distance between the end ray 10 on the edge of the rooftop 31 and a vertex of the rooftop 31 is not less than 10 cm (S15: NO), the control unit 21 determines whether or not a vertex 31A exists between the rays 10 (S17). As shown in Figures 11(c) and 11(d), at least one vertex 31A of the rooftop 31 exists between the rays 10 drawn at 10 cm intervals, so the hypothetical shaded area 13A of the diagonal line that would normally be in the shade is not surrounded by the rays 10 and is instead in the sun.

[0042] If a vertex 31A exists between the ray 10 (S17: YES), a vertex addition process is performed to add the vertex 31A to the shadow region (S16). Specifically, as shown in FIG. 11(c), a ray 10 is drawn with the vertex 31A as the starting point 11, and a collision point 12 is set. This allows the temporary shadow region 13A to be surrounded by the ray 10, so that the temporary shadow region 13A is incorporated into the shadow region 13 described below, allowing the shadow of the structure 30 to be represented with high accuracy. Similarly, as shown in FIG. 11(d), even if multiple vertices 31A exist between the ray 10, a vertex 31A existing between the ray 10 is set as the starting point 11. The processes from S11 to S16 performed by the control unit 21 are an example of the ray generation unit of the present invention.

[0043] When the processes from S11 to S16 are completed for all rays 10 (S18: YES), the control unit 21 normalizes the start points 11 and collision points 12 for creating polygons (S19). Specifically, as shown in the enlarged partial view of FIG. 10, the shadow area 13, which is made up of many collision points 12, is normalized to become linear, and only the vertices of each figure are recognized as points. As a result, the shadow area 13 is made up of many adjacent polygons, as shown in FIG. 10. The control unit 21 merges the adjacent polygons as shown in FIG. 10 to extract the outline of the periphery, and sets the shadow area 13, thereby creating shadow 2D data 26 as shown in FIG. 12 (S20).

[0044] The shadow 2D data 26 created by this process is stored as two-dimensional data in the storage unit 22 (S8). As shown in Fig. 3, in the offline processing, the sunlight vector V is calculated every 10 minutes on each date for one year, and the shadow 2D data 26 is created.

[0045] <Shadow shape map display flow> Next, the display flow of the shadow map creation system 1 on the user terminal 4 will be described with reference to Fig. 5. The user connects to the server 2 using the user terminal 4 via a predetermined application or web browser, and specifies the date and time at which they want to display the shadow map (S9). The control unit 21 overlays the shadow 2D data 26 created offline for the date and time specified by the user terminal 4 on the map 2D data 27, and displays the shadow map 20 as shown in Fig. 13 (S10).

[0046] <Structure addition processing> 14 to 16, a structure addition process in which a user adds a structure of any shape in the shadow map creation system 1 will be described. The structure addition process is entirely done online, but the added structure is saved in an account linked to the user and can be read out at any time.

[0047] As shown in Fig. 14, the user sets the shape of the additional structure 32, which is a structure to be added, from the user terminal 4 (S21). If the additional structure 32 is rectangular, the width, depth, and height are specified, but the shape is not limited to a rectangle and any shape, such as the roof shape or rooftop shape, can be set. The additional structure 32 of the specified size is displayed on the shadow map 20, and positioning is performed by rotating and moving the additional structure 32. The additional structure 32 on the shadow map 20 shown in Fig. 16 is set to a width of 60 m, a depth of 30 m, and a height of 179 m.

[0048] The control unit 21 extracts the roof shape of the additional structure 32 using substantially the same processing as S3 and creates rooftop shape 3D data 25 (S22). The created structure 3D data 24 and rooftop shape 3D data 25 of the additional structure 32 are stored in the storage unit 22 (S23). This completes the structure addition processing.

[0049] The control unit 21 calculates the sunlight vector V for the year, month, day, hour, minute, and second specified by the user using substantially the same process as S4 (S24). The control unit 21 creates starting points 11 so that rays 10 are spaced 10 cm apart between the end points of the rooftop 31 of the additional structure 32 using substantially the same process as S5 (S25).

[0050] The control unit 21 calculates the collision point 12 at the shortest distance where each ray 10 collides with the surface 30A of the other structure 30 or the ground surface 40 using substantially the same processing as S6 (S26), and creates the shadow 2D data 26 with the additional structure 32 added using substantially the same process as S7 (S27). The control unit 21 displays the map 2D data 27 with the additional structure 32 added and the shadow 2D data 26 in an overlapping manner, as shown in Fig. 16. This allows the user to check the shadow situation of the additional structure 32 of any shape on the shadow map 20, as shown in Fig. 16.

[0051] <Shadow generation by the ground> Next, the generation of the shadow 2D data 26 of the shadow generated by the uplift of the ground surface 40 in the shadow map creation system 1 according to this embodiment will be described with reference to Figs. 17 to 19. The same components as those in the above-described embodiment are given the same reference numerals and will not be described again. In the above flow, the shadow generated by the structure 30 was described, but below, the shadow generated by the valley, cliff, hill, mountain, etc. on the ground surface 40 will be described.

[0052] As shown in FIG. 17, the control unit 21 creates a starting point 11 of the ray 10 from the ground surface 50 of the 3D TIN of the map 3D data 23, and calculates the collision point with the surface 30A of the structure 30 or the ground surface 40, which is the shortest distance (S4, S5, S6). The ground surface 50 here refers to an area of the ground surface 40 that is high enough to cast a shadow. As in the case of the structure 30, a surface 40A and a back surface 40B are defined for all 3D TINs constituting the ground surface 40, and a starting point 11 is defined on the edge of the 3D TIN located downstream of the solar vector V on the ground surface 40 (S11). In areas of the ground surface 40 that are valleys or depressions, the starting point 11 of the ray 10 is not defined because the ray 10 will collide with the adjacent back surface 40B even if it is drawn. In other words, if the ray 10 is drawn on the surface 40A of an area of the ground surface 40 that is a protruding mountain or hill, the ray 10 will not be drawn because it will collide with the back surface 40B of the ground surface 40. On the back surface 40B of the ground surface 40 that protrudes into mountains or hills, if the ray 10 is drawn, it will collide with the surface 40A of the ground surface 40 or the surface 30A of the structure 30, and the ray 10 will be drawn.

[0053] Next, as shown in Fig. 18, the control unit 21 normalizes the start points 11 and collision points 12 for creating polygons (corresponding to S18). Specifically, the shadow area 13, which is made up of many collision points 12, is normalized to become linear, and only the vertices of each figure are recognized as points. As a result, the shadow area 13 is made up of many adjacent polygons, as shown in Fig. 18. The control unit 21 merges the adjacent polygons to extract the outlines of their peripheries, and sets the shadow area 13, thereby making it possible to create a shadow map 20 based on the elevation of the ground surface 40, as shown in Fig. 19.

[0054] <Shadow generation by structures> Next, the generation of shadow 2D data 26 of shadows generated by structures other than buildings, such as buildings, in the shadow map creation system 1 according to this embodiment will be described with reference to Figs. 20 to 22. Components that are the same as those in the above-described embodiment are given the same reference numerals and will not be described again. In the above flow, shadows generated by structures 30, such as buildings and houses, were described, but the following describes the shadow generated by Tokyo Tower, among the structures 30. Note that in the drawings, shadows are not generated for structures 30 other than Tokyo Tower, in order to make the drawings easier to see.

[0055] As shown in FIG. 20, the control unit 21 creates starting points 11 of rays 10 at equal intervals from each side of the 3D TIN of Tokyo Tower in the structural 3D data 24, and calculates the point of collision with the surface 30A or ground 40 of the structure 30, which is the shortest distance (corresponding to steps S4, S5, and S6). As with the other structures 30, a surface 40A and a back surface 40B are defined for all TINs constituting Tokyo Tower, and a starting point 11 is specified for each TIN on the side of the 3D TIN located downstream of the solar vector V (corresponding to step S11). Of the 3D TINs constituting Tokyo Tower, the TIN defined as the back surface 40A will not have a starting point 11 of the ray 10 defined for it, because even if a ray 10 is drawn, it will collide with the back surface 40B of Tokyo Tower. Of the 3D TINs constituting Tokyo Tower, the TIN defined as the back surface 40B will have a starting point 11 of the ray 10 defined for it, because even if a ray 10 is drawn, it will collide with the ground 40 or the surface 30A of another structure 30.

[0056] Next, as shown in FIG. 21, the control unit 21 normalizes the start points 11 and collision points 12 to create polygons (corresponding to S18). Specifically, the control unit 21 performs normalization to linearize the shadow area 13, which is composed of many collision points 12, and recognizes only the vertices of each figure as points. As a result, the shadow area 13 is composed of many adjacent polygons, as shown in FIG. 21. Note that the 3D TIN of Tokyo Tower has a complex shape and each TIN is set in detail, so the shadow area 13 in FIG. 21 appears solid. However, as in FIG. 18, the normalization of the start points 11 and collision points 12 results in many adjacent polygons. The control unit 21 merges adjacent polygons to extract the outline of the periphery and sets the shadow area 13, thereby creating a shadow map 20 based on Tokyo Tower, which is a structure 30, as shown in FIG. 22.

[0057] With this configuration, a shadow area 13 is created by combining rays 10 in the direction of the sunlight vector V, with the rooftop 31 as the starting point 11 and the ground 40 or the structure 30 as the ending point at the collision point 12. This allows the shadow cast by the structure 30 to be represented with high accuracy. Furthermore, because the structure 30 and the ground 40, which are the collision points 12, are set based on three-dimensional data, the shadow area 13 can be represented with high accuracy. This allows the creation of a shadow map 20 that meets users' needs, such as searching for a route that will allow them to walk in the shade as much as possible during the heat of summer. Furthermore, by referring to the shadow map 20, users can plan their departure time and route to their destination in advance. Furthermore, because the shadow map 20 is created based on the three-dimensional ground data 23 and the three-dimensional structure data 24, the shadow shape of the rooftop 31 and walls of the structure 30 can also be understood. This allows users to check the sunlight when considering where to install solar panels or searching for real estate. In particular, given the recent rise in summer temperatures and rising electricity rates, it is expected that there will be a growing demand for living in a shaded property. The shadow map 20 created by the shadow map creation system 1 can meet the needs of consumers who want to know highly accurate shadow position information.

[0058] With this configuration, the back surface 30B extracted by the control unit 21 is set as the starting point 11 of the ray 10, and the collision point 12 of the structure 30 or the ground surface 40 is set as the end point, so it is possible to represent the shadow with multiple rays 10 with high accuracy. This makes it possible to represent the shadow generated by the structure 30 and the ground surface 40 on the map with high accuracy. Furthermore, by generating rays 10 that collide with the front surface 30A of the structure 30 and not generating rays 10 that collide with the back surface 30B of the structure 30, it is possible to remove the rays 10 within the structure 30. This prevents the generation of a shadow within the structure 30, and allows the shadow map 20 to be generated with high accuracy.

[0059] With this configuration, a shadow area 13 is created by combining rays 10 in the direction of the sunlight vector V, with the rooftop 31 of the additional structure 32 as the starting point 11 and the collision point 12 where the rays collide with the ground 40 or the structure 30 as the ending point. This makes it possible to express with high accuracy the shadow area 13 created by the structure 30. In addition, since any shape can be set, it is possible to simulate the impact of shadows cast by buildings to be constructed on surrounding structures.

[0060] With this configuration, the back surface 30B extracted by the control unit 21 is set as the starting point 11 of the ray 10, and the collision point 12 with the structure 30 or the ground 40 is set as the end point, so that the shadow can be represented with high accuracy even for structures 30 other than buildings such as bridges and steel towers that cast shadows.

[0061] The shadow map creation system, shadow map creation method, and shadow map creation program according to the present invention are not limited to the above-described embodiments, and various modifications are possible within the scope of the gist of the invention described in the claims.

[0062] In the above-described embodiment, online processing and offline processing are separated as shown in Fig. 3, but this is not limiting. For example, all online real-time processing may be performed in response to a user request. This reduces the data capacity of the storage unit 22 of the server 2.

[0063] In the above-described embodiment, the shadow 2D data 26 and the map 2D data 27 are two-dimensional data, but this is not limiting. Three-dimensional shadow data may be created and superimposed on the ground 3D data 23 to generate a three-dimensional shadow shape map. This allows the user to visualize the shadow area in three dimensions, improving convenience.

[0064] In the above-described embodiment, the map 2D data 27 is a two-dimensional map of Japan or the world stored in the storage unit 22, but is not limited to this. Another map server may be accessed and the shadow map 20 may be overlaid on the map data of the map server using an API. This allows the shadow map to be generated using map data that the user normally uses.

[0065] In the above-described embodiment, the storage unit 22 stores the ground 3D data 23, structure 3D data 24, rooftop shape 3D data 25, shadow 2D data 26, and map 2D data 27, but this is not limiting. For example, each piece of data may be stored on a different server on the network, and each piece of data may be read by an application on the server 2. This reduces the load on the server 2. [Explanation of symbols]

[0066] 1. Shadow map creation system 2 Server 3. Administrator terminal 10 ray 11 Starting point 12 Collision point 12A Ground collision point 12B Structure collision point 13 Shadow area 20 Shadow Shape Map 21 Control section 22 Memory section 23 Map 3D data 24 Structural 3D data 25 3D rooftop shape data 26 Shadow 2D data 27 Map 2D data 30 Structures 30A surface 30B back side 31 Rooftop 32 Additional structures 40 ground V solar vector

Claims

1. a database in which shadow generation 3D data including information on the three-dimensional shape of a shadow generating body and map data are stored; a shape extraction unit that extracts a shape of the shadow generating body from the shadow generation 3D data; a ray generation unit that generates a plurality of rays in the sunlight vector direction at a specific time, with the shadow generating body as the starting point and the point of impact where the ray collides with another shadow generating body or the ground as the end point; a shadow data creation unit that creates shadow data by combining a plurality of the rays; A shadow map creation system comprising: a shadow map creation unit that displays the shadow data and the map data in an overlapping manner.

2. the shadow generation 3D data includes structure 3D data relating to a structure and ground 3D data relating to the ground, the shape extraction unit extracts, from the shape data of the structure based on the structural 3D data, a surface onto which sunlight is incident according to the sunlight vector and a back surface from which the sunlight is emitted from the structure when it is assumed that the sunlight passes through the structure; The shadow map generation system of claim 1, characterized in that the ray generation unit generates rays with the structure as the starting point and the point of collision where the ray collides with the ground or the surface of the structure in the shortest distance as the end point, and does not generate rays that collide with the back surface of the structure among the generated rays.

3. the shadow generation 3D data includes structure 3D data relating to a structure and ground 3D data relating to the ground, the shape extraction unit extracts, from the shape data of the ground based on the ground 3D data, a surface onto which sunlight is incident from the sunlight vector and a back surface onto which the sunlight is emitted from the ground when it is assumed that the sunlight is transmitted through the ground; The shadow map generation system of claim 1, characterized in that the ray generation unit generates rays with the back surface of the ground as the starting point and the point of collision where the ray collides with the ground or the structure in the shortest distance as the end point, and does not generate rays that collide with the back surface of the ground among the generated rays.

4. the shadow generation 3D data includes additional structure 3D data relating to an additional structure whose shape is specified by a user, the shape extraction unit extracts, from the shape data of the additional structure based on the additional structure 3D data, a front surface onto which sunlight is incident from the sunlight vector and a back surface from which the sunlight is emitted from the additional structure when it is assumed that the sunlight is transmitted through the ground; the ray generation unit generates the ray with the rear surface of the additional structure as a starting point and the collision point where the ray collides with the ground or the structure in the shortest distance as an end point; 2. The shadow map creation system according to claim 1, wherein the shadow data creation unit stores the shadow data created by combining the rays of the additional structures in the database.

5. preparing a database in which shadow generation 3D data including information on the three-dimensional shape of a shadow generating body and map data are stored; extracting a shape of the shadow generating body from the shadow generation 3D data; creating a plurality of rays in the sunlight vector direction at a specific time, with the outline of said shadow generating body as a starting point and the point of collision where said ray collides with another said shadow generating body or the ground as an ending point; generating shadow data by combining a plurality of said rays; a step of displaying the shadow data and the map data in an overlapping manner.

6. an information processing terminal including a database storing structure 3D data including information relating to the three-dimensional shape of a shadow generating body and map data; extracting a shape of the shadow generating body from the shadow generation 3D data; creating a plurality of rays in the sunlight vector direction at a specific time, with the outline of said shadow generating body as a starting point and the point of collision where said ray collides with another said shadow generating body or the ground as an ending point; generating shadow data by combining a plurality of said rays; and a step of displaying the shadow data and the map data in an overlapping manner.

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