Method for generating three-dimensional grid marked by projection coordinates

Abstract

The invention relates to the technical field of three-dimensional geographic information systems and geological exploration, in particular to a method for generating a three-dimensional grid marked by projection coordinates, which comprises the following steps of: acquiring geographic boundary ranges of all layers in a three-dimensional GIS (Geographic Information System) scene to form a boundary range set; calculating a minimum bounding cube of loaded resources of the scene according to the boundary range set; converting the coordinates of the minimum external cube into CGCS2000 projection coordinates, and constructing special linear equations of an XY plane and a YZ plane; calculating projection coordinates and geographic coordinates of all internal grid points of the XY plane and the YZ plane based on an equal division method; and generating a three-dimensional grid contour line, an internal grid line and labeling information based on the internal grid point projection coordinates and the geographic coordinates. According to the method, the three-dimensional grids under different projection coordinate systems can be automatically and adaptively generated; the generated three-dimensional grid can be associated with two-dimensional and three-dimensional layers in real time, dynamic display of coordinates under multiple view angles is supported, repeated conversion of projection coordinates is avoided, and loading and rendering efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the field of three-dimensional geographic information system and geological prospecting technology, and in particular to a method for generating a three-dimensional grid marked with projection coordinates. Background Art

[0002] In recent years, 3D GIS has been widely used in the fields of 3D engineering digital design, construction progress simulation, engineering safety monitoring and reverse modeling due to its powerful 2D and 3D integration, multi-source data fusion, visualization and dynamic interaction, spatial analysis and decision-making capabilities.

[0003] 3D GIS scenes generally use the CGCS2000 geographic coordinate system as the basis for spatial positioning, while fields such as design and construction generally use the CGCS2000 projected coordinate system. While design results, construction drawings, and BIM models can be integrated into 3D GIS scenes by converting these results into CGCS2000 geographic coordinates, it is difficult to intuitively and quickly obtain the projected coordinates of these results. This disconnects design and construction from geographic space, inefficiently collaborates with multi-source data, and hinders further spatial analysis and decision-making.

[0004] Among the existing patents, application number CN202011530444.8, invention title: A method for rapidly generating three-dimensional grid data maps of buildings realizes the generation of three-dimensional grid data maps of buildings, but its three-dimensional grid maps are spatially positioned based on plane projection coordinates, and do not involve integration with three-dimensional GIS scenes. It lacks the ability to combine, display, and analyze with multi-source heterogeneous GIS and BIM data.

[0005] Application number: CN202011063931.8, invention name: Beidou grid drawing method and device based on WebGL realizes efficient adaptive drawing of Beidou grid under the 3D WebGIS framework Cesium, but does not mention the marking of coordinates. In fields such as three-dimensional construction design, the inability to intuitively obtain projection information greatly limits the usage scenarios.

[0006] In summary, there is an urgent need to develop a method for generating a three-dimensional mesh annotated with projection coordinates. Summary of the Invention

[0007] To achieve the above object, the present invention provides the following technical solutions: According to a first aspect of the present invention, the present invention claims a method for generating a three-dimensional grid annotated with projection coordinates, comprising: Step S1: Obtain the geographic boundary ranges of all layers in the 3D GIS scene to form a boundary range set; Step S2: calculating a minimum circumscribed cube of the loaded resources of the scene according to the boundary range set; Step S3: converting the coordinates of the minimum circumscribed cube into CGCS2000 projection coordinates, and constructing special straight line equations of XY plane and YZ plane; Step S4: calculating all internal grid point projection coordinates and geographic coordinates of the XY plane and YZ plane based on bisection method; Step S5: generating solid grid contour lines, internal grid lines and label information based on the internal grid point projection coordinates and geographic coordinates.

[0008] Further, the step S1 comprises: Step S11: setting the coordinate system of the three-dimensional GIS scene as CGCS2000 geographic coordinate system or WGS84 geographic coordinate system; Step S12: traversing all 3D type layers, models and geometric bodies under the three-dimensional GIS scene to obtain corresponding geographic boundary ranges and geometric height ranges; Step S13: traversing all raster and vector layers under the three-dimensional GIS scene to obtain corresponding geographic boundary ranges, and setting the geometric height ranges bottomHeight and topHeight as 0.

[0009] Step S14: merging the boundary ranges obtained in step S12 and step S13 into the same set.

[0010] Further, the step S2 comprises: traversing the boundary range set obtained in step S1, calculating the minimum circumscribed cube of the loaded resources of the current three-dimensional GIS scene, and obtaining six range parameters east min , west max , north max , south min , bottomHeight min , and topHeight max in geographic coordinates.

[0011] Further, the step S3 comprises: Step S31: determining a projection coordinate system, and calculating the central longitude based on east min and west max ; (1); projection zone number , and determining the corresponding projection coordinate system according to the projection zone number; Step S32: calculating the projection coordinates of the minimum circumscribed cube by using Gauss projection direct formula, and obtaining Xmin 、X max 、Y min 、Y max、 Z min , Z max ; Step S33: Construct the special straight line equation in the XY plane: (2); (3); Step S34: Construct the special straight line equation of the YZ plane: (4); (5).

[0012] Furthermore, the step S4 includes: Step S41: Calculate the range of the three directions of X, Y, and Z, and determine the number of equal divisions in each direction 、 、 , calculate the equal interval 、 、 ; Step S42: Calculate the projection coordinates of all grid points along the Y-axis on the XY plane based on formula (2): (6); Step S43: converting the calculation result of step S42 into geographic coordinates based on the Gaussian inverse algorithm; Step S44: Repeat steps S42 and S43 to calculate the projection coordinates and geographic coordinates of all internal grid points along the X-axis direction of the XY plane and along the Y-axis direction and the Z-axis direction of the YZ plane.

[0013] Furthermore, the step S5 includes: Step S51: drawing a three-dimensional grid outline based on the geographic coordinates of the eight vertices of the minimum circumscribed cube, and drawing annotation information using corresponding projection coordinate values; Step S52: Draw all internal grid lines parallel to the X-axis of the XY plane, and draw annotation information at the grid points, including: In the 3D GIS scene, based on 、 Draw a line segment between the geographic coordinates of two points. Draw projection coordinate annotations; Step S53: Repeat step S52 to complete the drawing of all internal grid lines parallel to the Y axis of the XY plane; the Y axis and the Z axis of the YZ plane, and the marking of projection information of all internal grid points.

[0014] Compared with the prior art, the present invention has the following beneficial effects: The use of a 3D grid with projected coordinate annotations is proposed to address the problem of inconsistent spatiotemporal datums when combining digital engineering design, construction progress simulation, and other scenarios with 3D GIS scenarios. This makes it impossible for designers to intuitively present spatial information of related results in two sets of coordinates, making it difficult to support subsequent analysis and decision-making. The projection coordinate system is automatically derived through the known layer information of the scene, and it can automatically adapt to generate three-dimensional grids under different projection coordinate systems; All 2D and 3D layers are taken into account when calculating the minimum circumscribed cube, so that the generated three-dimensional grid can be associated with the 2D and 3D layers in real time, supporting dynamic coordinate display under multiple viewing angles; Internal grid points are determined based on the equal division method, which avoids repeated conversion of projection coordinates and improves loading and rendering efficiency.

[0015] The present invention relates to the field of three-dimensional geographic information systems and geological exploration technology, and in particular to a method for generating a three-dimensional grid annotated with projection coordinates, obtaining the geographic boundary ranges of all layers in a three-dimensional GIS scene to form a boundary range set; calculating the minimum circumscribed cube of the scene's loaded resources based on the boundary range set; converting the coordinates of the minimum circumscribed cube into CGCS2000 projection coordinates to construct special straight line equations for the XY plane and the YZ plane; calculating the projection coordinates and geographic coordinates of all internal grid points in the XY plane and the YZ plane based on an equal division method; and generating three-dimensional grid contour lines, internal grid lines, and annotation information based on the projection coordinates and geographic coordinates of the internal grid points. The present invention can automatically adapt to generating three-dimensional grids in different projection coordinate systems; the generated three-dimensional grid can be associated with two-dimensional and three-dimensional layers in real time, supports dynamic coordinate display under multiple perspectives, avoids repeated conversion of projection coordinates, and improves loading and rendering efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A flowchart of a method for generating a three-dimensional grid marked with projection coordinates as claimed in an embodiment of the present invention; Figure 2 A schematic diagram of the minimum circumscribed cube of a three-dimensional GIS scene claimed for protection in an embodiment of the present invention; Figure 3 This is a three-dimensional grid effect diagram requested for protection in an embodiment of the present invention. DETAILED DESCRIPTION

[0017] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0018] The terms "first," "second," and "third" in this disclosure are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features indicated. Therefore, features specified as "first," "second," or "third" may explicitly or implicitly include at least one of such features. In the description of this disclosure, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined. All directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of this disclosure are intended only to illustrate the relative positional relationships and movement of components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly. Furthermore, the terms "including," "having," and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements and may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to such process, method, product, or apparatus.

[0019] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute a separate or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0020] According to a first embodiment of the present invention, the present invention claims a method for generating a three-dimensional grid marked with projection coordinates, referring to Figure 1 ,include: Step S1: Obtain the geographic boundary ranges of all layers in the 3D GIS scene to form a boundary range set; Step S2: Calculating the minimum bounding cube of the loaded resources of the scene according to the boundary range set; Step S3: converting the coordinates of the minimum circumscribed cube into CGCS2000 projection coordinates, and constructing special straight line equations in the XY plane and the YZ plane; Step S4: Calculating the projection coordinates and geographic coordinates of all internal grid points in the XY plane and YZ plane based on the equal division method; Step S5: generating a solid grid contour line, an internal grid line and annotation information based on the internal grid point projection coordinates and geographic coordinates.

[0021] Further, the step S1 comprises: Step S11: setting the coordinate system of the three-dimensional GIS scene as a CGCS2000 geographic coordinate system or a WGS84 geographic coordinate system; Step S12: acquiring all 3D type layers, models, geometric bodies under the three-dimensional GIS scene, cesium series 3D platform can be acquired through scene layers and primitives, all 3D type layers, models, geometric bodies are traversed, and corresponding geographic boundary range GeoBounds (including the westmost longitude west, the eastmost longitude east, the southmost latitude south, and the northmost latitude north) and geometric height range HeightReference (including the bottom height bottomHeight and the top height topHeight) are read; Step S13: acquiring all raster and vector layers under the three-dimensional GIS scene, cesium series 3D platform can acquire through scene imageryLayers, all raster and vector layers are traversed, and corresponding geographic boundary range GeoBounds (including the westmost longitude west, the eastmost longitude east, the southmost latitude south, and the northmost latitude north) is read, since the raster and vector layers have no geometric height information, the geometric height range bottomHeight and topHeight are both set to 0; Step S14: merging the boundary ranges acquired in steps S12 and S13 into the same set.

[0022] Further, the step S2 comprises: The boundary range set acquired in the step S1 is traversed, and the minimum circumscribed cube of the loaded resources of the current three-dimensional GIS scene is calculated, specifically, west, east, south, north, bottomHeight, and topHeight are compared to obtain six range parameters expressed in geographic coordinates, east min , west max , north max , south min , bottomHeight min , and topHeight max .

[0023] Further, the step S3 comprises: Step S31: Determine the projection coordinate system based on east min 、west max Calculate the center longitude: (1); Projection tape number , determine the corresponding projection coordinate system under the 3° zone of the CGCS2000 Gauss-Krüger projection according to the projection zone number; Step S32: Set the coordinate point (east min ,north max )、(east min ,south min )、(west max ,north max )、(west max ,south min ) is brought into the Gauss projection forward calculation formula to calculate the maximum and minimum ranges X in the X and Y directions on the projection surface max 、X min 、Y max 、Y min , the maximum and minimum range of geometric height Z max , Z min Directly taken from topHeight max 、bottomHeight min At this point, the smallest bounding cube of the loaded resources in the three-dimensional GIS scene can be expressed by two sets of coordinates, namely geographic coordinates (east min 、west max 、north max 、south min 、bottomHeight min 、topHeight max ) and projection coordinates (X min 、X max 、Y min 、Y max、 Z min , Z max ); Reference Figure 2 , get the minimum circumscribed cube in the three-dimensional GIS scene; Step S33: Construct the special straight line equation in the XY plane: (2); (3); Step S34: Construct the special straight line equation of the YZ plane: (4); (5).

[0024] Furthermore, the step S4 includes: Step S41: Calculate the range in the X, Y, and Z directions 、 、 , determine the number of equal divisions in each direction 、 、 , calculate the equal interval 、 、 ; Step S42: Based on formula (2), the number of equal divisions in the Y direction , equal spacing Calculate the projection coordinates of all grid points along the Y axis on the XY plane. Since the grid points projected along the Y axis are distributed and On two straight lines, the projection coordinates of two grid points that can be subsequently connected to form the internal lines of the grid are uniformly expressed by the following formula: (6); Step S43: converting the calculation result of step S42 into geographic coordinates based on the Gaussian inverse algorithm; Step S44: Repeat steps S42 and S43 to calculate the projection coordinates and geographic coordinates of all internal grid points along the X-axis direction of the XY plane and along the Y-axis direction and the Z-axis direction of the YZ plane.

[0025] Furthermore, the step S5 includes: Step S51: drawing a three-dimensional grid outline based on the geographic coordinates of the eight vertices of the minimum circumscribed cube, and drawing annotation information using corresponding projection coordinate values; Reference Figure 3 , is the generated three-dimensional grid effect; Step S52: Draw all internal grid lines parallel to the X-axis of the XY plane, and draw annotation information at the grid points, including: In the 3D GIS scene, based on 、 Draw a line segment between the geographic coordinates of two points. Draw projection coordinate annotations; Step S53: Repeat step S52 to complete the drawing of all internal grid lines parallel to the Y axis of the XY plane; the Y axis and the Z axis of the YZ plane, and the marking of projection information of all internal grid points.

[0026] In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other ways. For example, the device embodiments described above are merely illustrative, for example, the division of units is only a logical function division, and actual implementation can have other division manners, for example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interfaces, devices or units, and can be electrical, mechanical or other forms.

[0027] In addition, each functional unit in each embodiment of the present application can be integrated into a processing unit, or each unit can exist physically, or two or more units can be integrated into one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit. The above is only an embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation using the content of the present application specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

[0028] The specific embodiments of the application are described in detail above, but they are only examples. The present application is not limited to the specific embodiments described above. Any equivalent modification or substitution made by those skilled in the art to the present application is also within the scope of the present application, and therefore, any equivalent transformation, modification, improvement, etc. made without departing from the spirit and principle range of the present application should be included in the scope of the present application.

Claims

1. A method for generating a three-dimensional grid annotated with projection coordinates, characterized in that: include: Step S1: Obtain the geographic boundary ranges of all layers in the 3D GIS scene to form a boundary range set; Step S2: Calculating the minimum bounding cube of the loaded resources of the scene according to the boundary range set; Step S3: converting the coordinates of the minimum circumscribed cube into CGCS2000 projection coordinates, and constructing special straight line equations in the XY plane and the YZ plane; Step S4: Calculating the projection coordinates and geographic coordinates of all internal grid points in the XY plane and YZ plane based on the equal division method; Step S5: generating a three-dimensional grid outline, internal grid lines and annotation information based on the internal grid point projection coordinates and geographic coordinates.

2. The method for generating a three-dimensional grid marked with projection coordinates according to claim 1, characterized in that: The step S1 comprises: Step S11: setting the coordinate system of the three-dimensional GIS scene to the CGCS2000 geographic coordinate system or the WGS84 geographic coordinate system; Step S12: traverse all 3D layers, models, and geometric bodies in the 3D GIS scene to obtain corresponding geographic boundary ranges and geometric height ranges; Step S13: traverse all raster and vector layers in the three-dimensional GIS scene, obtain the corresponding geographic boundary range, and set the geometric height range bottomHeight and topHeight to 0; Step S14: Merge the boundary ranges obtained in steps S12 and S13 into the same set.

3. The method for generating a three-dimensional grid marked with projection coordinates according to claim 2, characterized in that: The step S2 comprises: Traverse the boundary range set obtained in step S1, calculate the minimum circumscribed cube of the loaded resources in the current 3D GIS scene, and obtain six range parameters expressed in geographic coordinates. min 、west max 、north max 、south min 、bottomHeight min 、topHeight max .

4. The method for generating a three-dimensional grid marked with projection coordinates according to claim 1, characterized in that: The step S3 comprises: Step S31: Determine the projection coordinate system based on east min 、west max Calculate the center longitude: （1）； Projection tape number , determine the corresponding projection coordinate system according to the projection zone number; Step S32: Use the Gauss projection forward calculation formula to calculate the projection coordinates of the minimum circumscribed cube and obtain X min 、X max 、Y min 、Y max、 Z min , Z max ; Step S33: Construct the special straight line equation in the XY plane: （2）； （3）； Step S34: Construct the special straight line equation of the YZ plane: （4）； （5）。 5. The method for generating a three-dimensional grid marked with projection coordinates according to claim 4, characterized in that: The step S4 comprises: Step S41: Calculate the range of the three directions of X, Y, and Z, and determine the number of equal divisions in each direction 、 、 , calculate the equal interval 、 、 ; Step S42: Calculate the projection coordinates of all grid points along the Y-axis on the XY plane based on formula (2): (6)； Step S43: converting the calculation result of step S42 into geographic coordinates based on the Gaussian inverse algorithm; Step S44: Repeat steps S42 and S43 to calculate the projection coordinates and geographic coordinates of all internal grid points along the X-axis direction of the XY plane and along the Y-axis direction and the Z-axis direction of the YZ plane.

6. The method for generating a three-dimensional grid marked with projection coordinates according to claim 4, characterized in that: The step S5 comprises: Step S51: drawing a three-dimensional grid outline based on the geographic coordinates of the eight vertices of the minimum circumscribed cube, and drawing annotation information using corresponding projection coordinate values; Step S52: Draw all internal grid lines parallel to the X-axis of the XY plane, and draw annotation information at the grid points, including: In the 3D GIS scene, based on 、 Draw a line segment between the geographic coordinates of two points. Draw projection coordinate annotations; Step S53: Repeat step S52 to complete the drawing of all internal grid lines parallel to the Y axis of the XY plane; the Y axis and the Z axis of the YZ plane, and the marking of projection information of all internal grid points.

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