A situation map two-three-dimensional integrated rendering method

Abstract

The application discloses a kind of situation map two three-dimensional integration rendering method, the method is based on tile pyramid model organization two three-dimensional map data, by real-time projection transformation realizes two three-dimensional dynamic switching.Grid tile and vector tile are used to efficiently render remote sensing image and vector;Integrated situation graphics library is constructed, unified organization and rendering of situation target graphics are realized, and the efficiency of graphics rendering is improved by using GPU hardware acceleration.Compared with traditional two three-dimensional view independent rendering, it saves storage space, reduces data redundancy, realizes two three-dimensional real-time dynamic switching under the same view, and provides unified display effect.Using vector tile significantly improves the efficiency of vector data rendering, and the integrated graphics library provides a faster way for situation graphics display, making battlefield environment simulation more convenient and smooth, and improving user experience.

Description

Technical Field

[0001] This invention relates to a situation map rendering method, and more particularly to a situation map rendering method. Figure 2 A three-dimensional integrated rendering method. Background Technology

[0002] Situation maps in battlefield environment simulation systems typically have both two-dimensional and three-dimensional display modes. The two-dimensional mode displays basic geographic information data through a projected planar map, while the three-dimensional mode uses a three-dimensional Earth model. In practical applications, users usually want to be able to browse using both display modes and switch freely between them.

[0003] Typically, 2D and 3D displays use two views, rendered independently with different rendering engines and logic. The rendered images need to be linked together to maintain consistency in the displayed content. This approach ensures that the rendering of the two views does not interfere with each other and allows for rapid switching between views. However, this approach leads to differences in the display effects of the two views and requires storing two sets of rendering data, including vertex data, texture data, and rendering state information, resulting in data redundancy. Furthermore, the differences in rendering engines complicate the graphics development process. Additionally, extra relationships need to be established to maintain consistency in the displayed content of the two views.

[0004] Traditional vector data rendering typically uses raster tiles to divide the global area into tiles, then renders the vector data within each tile area as raster images for storage. During map rendering, the raster image with the corresponding tile code is used for rendering. Raster tile rendering is highly efficient, but it cannot meet the needs of updating vector data and customizing display requirements. Summary of the Invention

[0005] Objective of the Invention: The technical problem to be solved by the present invention is to address the shortcomings of the prior art and provide a situational... Figure 2 A three-dimensional integrated rendering method.

[0006] To address the aforementioned technical problems, this invention discloses a situational... Figure 2 The 3D integrated rendering method includes the following steps:

[0007] Step 1, Global Tile Organization: Based on the tile pyramid model, establish the Earth tile structure, and construct a two-dimensional and three-dimensional situation map based on the Earth tiles;

[0008] Step 2, Rendering of basic geographic information data: The remote sensing image data is rendered using the raster tile method, and the vector data is rendered using the vector tile method, thus completing the rendering of the basic geographic information data in the two-dimensional and three-dimensional situation map.

[0009] Step 3, Integrated Graphic Rendering: Construct an integrated 2D and 3D situation graphic symbol library. Based on a unified graphic data organization structure, drawing method and process, design and establish the display styles of commonly used situation graphics in the two display modes of the 2D and 3D situation map.

[0010] Step 4, Dynamic switching between 2D and 3D display modes: When switching between 2D and 3D display modes, the Earth tiles within the field of view are reconstructed with the intersection of the line of sight and the Earth as the center. The change model of the Earth tiles in 2D and 3D modes is established by interpolation to show the dynamic process of switching between 2D and 3D modes. The display style of the integrated situational graphic is adaptively switched when the display mode is switched.

[0011] Beneficial effects:

[0012] 1. The two-dimensional and three-dimensional rendering adopts a unified basic geographic information data organization structure, which can save storage space and reduce data redundancy;

[0013] 2. It adopts a consistent vertex mesh construction method, thus supporting real-time dynamic switching between 2D and 3D display modes;

[0014] 3. By using vector tiles to render vector data, combined with GPU hardware acceleration technology, faster data loading and more efficient cache management can be achieved, enabling efficient rendering of vector data.

[0015] 4. It adopts an integrated 2D and 3D graphic symbol library, which can conveniently and quickly meet the rendering needs of commonly used graphics in situation map display. At the same time, it can automatically switch the display style according to the 2D and 3D display mode to display graphic symbols that conform to the characteristics of 2D and 3D maps. Attached Figure Description

[0016] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, and the advantages of the present invention in the above and / or other aspects will become clearer.

[0017] Figure 1 This is a flowchart illustrating the overall implementation of the present invention.

[0018] Figure 2 This is a schematic diagram of the global tile organization implemented in this invention.

[0019] Figure 3 This is a schematic diagram of the basic geographic information data rendering for the implementation of this invention.

[0020] Figure 4 This is a flowchart of the integrated situational graphics library implemented in this invention. Detailed Implementation

[0021] This invention proposes a situational approach Figure 2A unified 3D rendering method organizes spatial geographic information data to construct an integrated 2D and 3D map display environment. It employs a unified 2D and 3D rendering engine to render maps and situational graphics. While allowing for dynamic switching of display modes, it unifies the rendering process and display effects, reducing data redundancy. Raster tile technology and vector tile technology are used to efficiently organize and render remote sensing image data and vector data respectively, ensuring the display efficiency of basic geographic information data for the situational map. Simultaneously, for the rendering of situational graphics, a unified 2D and 3D graphics rendering framework is constructed, realizing the organization and rendering of situational targets within the 2D and 3D map display environment and simplifying the rendering process.

[0022] like Figure 1 As shown, this method first establishes a unified 2D and 3D geographic information data organization structure based on a tile pyramid model, constructing 2D and 3D situation maps using Earth tiles as the foundation. Then, raster tile technology is used to organize and render remote sensing image data, and vector tile technology is used to organize and render vector data, completing the rendering of the basic geographic information data in the situation map. Furthermore, based on a unified graphic data organization structure, drawing method, and workflow, the method designs and establishes display styles for commonly used situation graphics in 2D and 3D map display modes, achieving adaptive display of commonly used situation graphics in 2D and 3D modes.

[0023] To address the fragmentation in data organization and graphics rendering of 2D and 3D situation maps in current battlefield environment simulation systems, resulting in data redundancy, inconsistent display styles, and low efficiency in vector element rendering, this invention proposes a situation map... Figure 2 The integrated 3D rendering method and engine enables unified organization and rendering of 2D and 3D situational maps, and provides the ability to dynamically switch between 2D and 3D maps in real time. The process includes the following steps:

[0024] Step 1, Global Tile Organization. Select the corresponding tile model based on the projection type. Using a pyramid model, divide the global area to establish a global pyramid tile structure. Within each tile, uniformly divide its longitude and latitude range to obtain an n*n regular grid. In 2D mode, calculate the planar projection coordinates of the tile grid points using the map projection calculation formula; in 3D mode, calculate the spatial coordinates of the tile grid points using the spherical calculation formula. Construct the tile vertex mesh data for GPU rendering.

[0025] Step 2, Rendering of Basic Geographic Information Data. The situation map uses remote sensing imagery data and vector data to represent the map's basic geographic information. Remote sensing imagery data is stored as raster tiles, sampled according to the same pyramid model as Earth tiles, resulting in raster tiles of specified "level_row_column". Vector data is stored as vector tiles. Based on the vector tile data model, the spatial entity geometry data and multi-dimensional attribute data stored in the vector data are organized into tiles, achieving vector tile storage at the point, line, and polygon feature levels. This is submitted to the GPU for rendering along with the vertex mesh data as texture data.

[0026] Step 3: Integrated Situational Graphics Library. For commonly used situational graphics symbols, establish a unified graphic organization structure, including their display styles in 2D and 3D modes, vertex composition, and graphics rendering status. Based on the different display styles of the graphics in 2D and 3D maps, they are spatial solid graphics in 3D mode and planar projection graphics in 2D mode. Calculate the geometric vertex coordinates, construct triangular meshes, and associate them. Use the corresponding display styles in 2D and 3D modes to construct meshes, submit vertex data to the GPU for rendering, and automatically switch the associated styles and reconstruct the vertex meshes when switching between 2D and 3D display modes.

[0027] Step 4, Dynamic switching between 2D and 3D display modes. When switching between 2D and 3D display modes, the Earth tiles within the field of view are reconstructed with the intersection of the line of sight and the Earth as the center. A change model of the Earth tiles in 2D and 3D modes is established by interpolation. The spatial position of the grid points is calculated frame by frame, and the vertex buffer object is updated to show the dynamic process of switching between 2D and 3D modes.

[0028] Step 1 includes:

[0029] Step 1-1: Seamlessly divide the global area to construct a global multi-level pyramid model and obtain the top-level tile.

[0030] Steps 1-2 involve organizing the tiles hierarchically based on a pyramid model, with each upper-level tile evenly divided into four lower-level tiles.

[0031] Steps 1-3 involve organizing each tile into a "hierarchical_row_column" structure to obtain the global tile geographic range. The geographic range of each Earth tile is then uniformly divided to obtain an n*n regular grid.

[0032] Steps 1-4: In 2D map mode, calculate the planar projection coordinates of the tile grid points according to the map projection calculation formula; in 3D map mode, calculate the spatial coordinates of the tile grid points according to the spherical coordinate calculation formula, and calculate the texture coordinates based on the relative positions of the projected coordinates of each vertex within the tile. The vertex structure of the grid points includes the coordinate offsets relative to the grid center point (offsetX, offsetY, offsetZ), the normal vector (nx, ny, nz), and the texture coordinates (u, v). A vertex buffer object (VBO) is constructed from all grid points within the tile. The tile grid is triangulated, with each rectangular grid divided into two triangular grids, and an index buffer object (EBO) is constructed from the vertex indices of the triangular grids.

[0033] Steps 1-5: When switching between 2D and 3D display modes, the tiles within the current visible range are reconstructed. The vertex projection coordinates and texture coordinates are recalculated based on the geographic coordinates of the tile vertices, resulting in new vertex buffer objects and index buffer objects. To represent the dynamic switching process, linear interpolation is performed between spherical coordinates and planar projection coordinates. The changes in the sphere and projection plane are simulated by modifying the vertex positions frame by frame.

[0034] Step 2 includes:

[0035] Step 2-1: Calculate the pixel region of the remote sensing image corresponding to the tile range according to the map projection formula, the offset (xOffset, yOffset) relative to the pixel coordinate origin, and the pixel width and height (xSize, ySize). Sample the remote sensing image data, read the pixels of the specified range in the raster image, obtain the raster tile data RasterData corresponding to each Earth tile, and construct the texture object.

[0036] Step 2-2: Through spatial query, query the spatial entity objects that fall within the geographical range of the tile in the vector data, cut the vector data according to the tile range, and remove the parts that are not within the geographical range of the tile to obtain vector slices.

[0037] Step 2-3: For the tiled vector tiles in Step 2-2, during map rendering, obtain the vertex geographic coordinates of spatial entities to form spatial point, line, and surface objects. According to the customized display style, triangulate the spatial entity symbols in the tiles to obtain vertex buffer objects and index buffer objects, and submit them for GPU rendering.

[0038] Step 3 includes:

[0039] Step 3-1: For commonly used situational graphic symbols, establish a unified graphic organization structure in two-dimensional and three-dimensional modes, including display style, vertex composition and graphic rendering status in two-dimensional and three-dimensional modes. Based on the different display styles in two-dimensional and three-dimensional modes, construct triangular meshes and render them according to a unified update and rendering process.

[0040] Step 3-2: When selecting a predefined situational graphic from the rendering graphics library, use its corresponding display style in both 2D and 3D modes to calculate local coordinates, construct vertex meshes, obtain vertex buffer objects and index buffer objects, and submit them for GPU rendering.

[0041] Step 3-3: When switching between 2D and 3D display modes, recalculate the geometric vertex coordinates, reconstruct the vertex buffer object and index buffer object, and submit the rendering.

[0042] Step 4 includes:

[0043] Step 4-1: Construct variation models of Earth tiles in two-dimensional and three-dimensional modes. Using Earth tile grid points as the basic unit, determine their spatial position in the two-dimensional mode through projection calculation and their spatial position in the three-dimensional mode through spherical calculation.

[0044] Step 4-2: Interpolate the two-dimensional and three-dimensional spatial coordinates of the same grid point, establish a calculation formula for the change of grid point coordinates over time, and calculate the spatial position of the grid point at a certain time point frame by frame, with the intersection of the current line of sight and the earth as the center.

[0045] Step 4-3: Update the vertex buffer object of the mesh to represent the smooth transition process of mode switching by changing the spatial position of mesh points over a specified time.

[0046] a situation Figure 2 The 3D integrated rendering method, based on seamless global segmentation, calculates the vertex coordinates of each segmented Earth tile according to different display modes and projection methods, thereby constructing the grid data required for rendering. Building upon this, raster tile technology and vector tile technology are used to efficiently render remote sensing image data and vector data respectively, constructing the basic geographic information environment for the situational map. This reduces data redundancy and maintains consistency of displayed content without establishing additional relationships. The use of vector tile technology significantly improves the rendering efficiency of basic vector data, making battlefield environment simulation more convenient and smoother, and providing a better user experience.

[0047] Example:

[0048] This method mainly consists of three parts: global tile organization, basic geographic information data rendering, and an integrated situational graphics library. The following provides a detailed description of the process for each part.

[0049] 1. Global Tile Organization

[0050] Select the appropriate tile model based on the projection type. Using a pyramid model, subdivide the global area to establish a global pyramid tile structure. Within each tile, uniformly divide its longitude and latitude range to obtain an n*n regular grid. In 2D mode, calculate the planar projection coordinates of the tile grid points using map projection formulas; in 3D mode, calculate the spatial coordinates of the tile grid points using spherical coordinate formulas. Construct tile vertex mesh data for GPU rendering. Figure 2 As shown, the detailed steps are as follows:

[0051] (1) A global multi-level pyramid model is constructed by seamlessly dividing the global area, with North latitude as positive value, South latitude as negative value, East longitude as positive value, and West longitude as negative value. The global latitude range is -90° to 90°, and the longitude range is -180° to 180°. Taking the equal latitude and longitude projection as an example, it is divided into 1*2. Level 0 contains 2 tiles, namely the tile numbered 0_0_0, whose longitude range is -180° to 0° and latitude range is -90° to 90°, and the tile numbered 0_0_1, whose longitude range is 0° to 180° and latitude range is -90° to 90°.

[0052] (2) The tiles are hierarchically organized based on the pyramid model. A higher-level tile is evenly divided into four lower-level tiles. That is, the tile numbered 0_0_0 can be divided into four tiles numbered 1_0_0, 1_0_1, 1_1_0, and 1_1_1, and the tile numbered 0_0_1 can be divided into four tiles numbered 1_0_2, 1_0_3, 1_1_2, and 1_1_3. The lower-level tiles are divided in sequence.

[0053] (3) For any tile, given its latitude and longitude ranges as longitude L1 to L2 and latitude B1 to B2, perform uniform sampling, dividing the longitude and latitude ranges into n segments, with each segment spanning (L2-L1) / n and (B2-B1) / n. In the formula, L2 is greater than L1, B2 is greater than B1, and the unit is degrees.

[0054] (4) For the vertices in the n*n grid calculated in the previous step, calculate the geographic coordinates (L, B) of each vertex using latitude and longitude, in degrees. In 2D mode, use the map projection formula to calculate the planar projected coordinates; in 3D mode, use the spherical coordinate calculation formula to calculate the spherical coordinates. Then, calculate the offset values ​​(xOffset, yOffset, zOffset) of each vertex relative to the tile center coordinates to construct a local coordinate grid, in meters. Calculate the texture coordinates (u, v) based on the relative positions of the vertex's projected coordinates within the tile, u = dx / xSize, v = dy / ySize, where dx is the offset of the point relative to the top-left corner coordinate in the x-direction, xSize is the total length of the tile in the x-direction, dy is the offset of the point relative to the top-left corner coordinate in the y-direction, and ySize is the total length of the tile in the y-direction, in meters, thus obtaining the vertex buffer object and the index buffer object.

[0055] (5) When switching between 2D and 3D display modes, the tiles within the current visible range are reconstructed. The vertex projection coordinates and texture coordinates are recalculated based on the geographic coordinates of the tile vertices to obtain new vertex buffer objects and index buffer objects. To represent the dynamic switching process, linear interpolation is performed between spherical coordinates and planar projection coordinates. The changes in the sphere and projection plane are simulated by modifying the vertex positions frame by frame.

[0056] 2. Rendering of basic geographic information data

[0057] The situation map uses remote sensing imagery data and vector data to represent the map's basic geographic information. Remote sensing imagery data is stored as raster tiles, sampled according to a pyramid model similar to Earth tiles, resulting in raster tiles of specified "level_row_column". Vector data is stored as vector tiles, organized into tiles based on a vector tile data model, achieving point, line, and polygon feature-level vector tile storage. This is submitted to the GPU for rendering along with the vertex mesh data, serving as texture data. Figure 3 As shown, the detailed steps are as follows:

[0058] (1) Cropping raster tiles according to the range of Earth tiles. Given the geographical range of Earth tiles, calculate the pixel area of ​​the remote sensing image corresponding to the range of the tile according to the projection formula, the offset (xOffset, yOffset) of the starting point of the area relative to the origin of the pixel coordinates, and the pixel width and height (xSize, ySize) of the area, in pixels. Sample the remote sensing image data, read the pixels of the specified range in the raster image, obtain the raster tile data RasterData corresponding to each Earth tile, construct a texture object, and associate it with the Earth tile.

[0059] (2) By spatial query, query the spatial entity objects that fall within the geographical range of the tile in the vector data, cut the vector data according to the tile range, remove the parts that are not within the geographical range of the tile, the vector tile contains fragments of multiple spatial entity objects, and associate them with the Earth tile.

[0060] (3) During map rendering, find the vector tile associated with the Earth tile, obtain the vertex geographic coordinates of the spatial entity in it, form point, line and surface objects, triangulate the spatial entity symbols according to the customized display style, obtain vertex buffer objects and index buffer objects, and submit them to GPU rendering.

[0061] 3. Integrated situational graphics library

[0062] For commonly used situational graphic symbols, a unified graphic organization structure is established, including their display styles, vertex composition, and graphic rendering states in 2D and 3D modes. Based on the different display styles of the graphics in 2D and 3D maps, they are spatial solid graphics in 3D mode and planar projected graphics in 2D mode. Geometric vertex coordinates are calculated, triangular meshes are constructed, and associated relationships are established. Corresponding display styles are used in 2D and 3D modes respectively to construct meshes, and vertex data is submitted to the GPU for rendering. Simultaneously, when switching between 2D and 3D display modes, the associated styles are automatically switched, and the vertex mesh is reconstructed. For example... Figure 4 As shown, the detailed steps are as follows:

[0063] (1) Establish a unified base class for graphics, providing common methods in the standard update and rendering process (including initialization, vertex calculation, mesh construction, clipping judgment, state update, rendering, and destruction, etc.), and establish a graphics management class to implement unified management of graphics. Select the graphics type and use the graphics library to quickly create commonly used situation graphics.

[0064] (2) Commonly used situational graphics derive their respective graphics implementation classes from the graphics base class to complete the specific operations in the update rendering process. In two-dimensional and three-dimensional modes, their display styles, vertex compositions, and graphics rendering states are established respectively. According to different display styles, a three-dimensional space mesh is constructed in three-dimensional mode and a planar projection mesh is constructed in two-dimensional mode. The geometric vertex coordinates are calculated, the rendering state is updated, vertex buffer objects and index buffer objects are obtained, and the results are submitted to the GPU for rendering.

[0065] (3) When switching between two-dimensional and three-dimensional display modes, recalculate the geometric vertex coordinates to obtain new vertex buffer objects and index buffer objects, and submit for rendering.

[0066] 4. Dynamic switching between 2D and 3D display modes

[0067] When switching between 2D and 3D display modes, the Earth tiles within the field of view are reconstructed with the intersection of the line of sight and the Earth as the center. The change model of the Earth tiles in 2D and 3D modes is established by interpolation. The spatial position of the grid points is calculated frame by frame, and the vertex buffer object is updated to show the dynamic process of switching between 2D and 3D modes.

[0068] (1) Construct a variation model of Earth tiles in two-dimensional and three-dimensional modes. Using Earth tile grid points as the basic unit, for each vertex (L, B) in the grid, the projected coordinates P1 in the two-dimensional mode are calculated by map projection, and the spatial coordinates P2 in the three-dimensional mode are calculated by spherical calculation.

[0069] (2) Interpolate the two-dimensional model coordinates P1 and three-dimensional model coordinates P2 of the same grid point. Taking the intersection of the current line of sight and the Earth P0 as the center, calculate the coordinates P3 and P4 of P1 and P2 in the coordinate system centered at P0. During the change from time t0 to t1, calculate the grid point coordinates P at a certain time t using interpolation. The weight of time t in this time period is determined by the function f(t), P = P3 + (P4 - P3) * f(t). Calculate the position of each grid point at a certain time point frame by frame. The weight of time t is calculated as follows: f(t) = 1 - ((t - t0) / (t1 - t0) - 1)^4, where t is between t0 and t1, and the unit is milliseconds.

[0070] (3) During this time period, calculate the spatial position of each vertex in each frame, update the vertex buffer object of the mesh according to the changes in vertex coordinates, and submit the rendering. The smooth transition between 2D and 3D modes is represented by the continuous change in the spatial position of the mesh points.

[0071] In its specific implementation, this application provides a computer storage medium and a corresponding data processing unit. The computer storage medium is capable of storing a computer program, which, when executed by the data processing unit, can run the situational information provided by this invention. Figure 2 The invention content of the three-dimensional integrated rendering method and some or all of the steps in various embodiments are described. The storage medium may be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc.

[0072] Those skilled in the art will clearly understand that the technical solutions in the embodiments of the present invention can be implemented using computer programs and their corresponding general-purpose hardware platforms. Based on this understanding, the technical solutions in the embodiments of the present invention, or the parts that contribute to the prior art, can be embodied in the form of computer programs, i.e., software products. These computer program software products can be stored in a storage medium and include several instructions to cause a device containing a data processing unit (which may be a personal computer, server, microcontroller, MUU, or network device, etc.) to execute the methods described in various embodiments or certain parts of the embodiments of the present invention.

[0073] This invention provides a situational approach Figure 2 The concept and methods of the three-dimensional integrated rendering method are numerous, and there are many specific methods and approaches to implement this technical solution. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention. All components not explicitly stated in this embodiment can be implemented using existing technologies.

Claims

1. A method for integrated 2D and 3D rendering of a situation map, characterized in that, Includes the following steps: Step 1, Global Tile Organization: Based on the tile pyramid model, establish the Earth tile structure, and construct a two-dimensional and three-dimensional situation map based on the Earth tiles; Step 2, Rendering of basic geographic information data: The remote sensing image data is rendered using the raster tile method, and the vector data is rendered using the vector tile method, thus completing the rendering of the basic geographic information data in the two-dimensional and three-dimensional situation map. Step 3, Integrated Graphic Rendering: Construct an integrated 2D and 3D situation graphic symbol library. Based on a unified graphic data organization structure, drawing method and process, design and establish the display styles of commonly used situation graphics in the two display modes of the 2D and 3D situation map. Step 4, Dynamic switching between 2D and 3D display modes: When switching between 2D and 3D display modes, the Earth tiles within the field of view are reconstructed with the intersection of the line of sight and the Earth as the center. The change model of the Earth tiles in 2D and 3D modes is established by interpolation to show the dynamic process of switching between 2D and 3D modes. The display style of the integrated situational awareness graphic automatically switches when the display mode changes; The integrated graphics rendering described in step 3 specifically includes: Step 3-1: For situational graphic symbols, establish a unified graphic organization structure in two-dimensional and three-dimensional modes, including: display style, vertex composition and graphic rendering status in two-dimensional and three-dimensional modes. Based on the different display styles in two-dimensional and three-dimensional modes, construct a triangular mesh and render it according to a unified update rendering process. Step 3-2: When selecting a predefined situational graphic from the rendering graphics library, use the corresponding display style in 2D and 3D modes respectively, calculate local coordinates, construct vertex mesh, obtain vertex buffer objects and index buffer objects, and submit for GPU rendering. Step 3-3: When switching between 2D and 3D modes for display, recalculate the geometric vertex coordinates, reconstruct the vertex buffer object and index buffer object, and submit the rendering. The situation graphic symbols include basic graphic symbols and situation graphic symbols. The basic graphic symbols include at least: circles, rectangles, ellipses and polygons. The situation graphic symbols include at least: radar, transmission and flight path.

2. The integrated two-dimensional and three-dimensional rendering method for situation maps according to claim 1, characterized in that, The global tile organization described in step 1 includes the following specific methods: Step 1-1: Construct a pyramid model and select the form of the top-level tile according to the projection type. Perform seamless subdivision of the global area according to the pyramid model, that is, divide the pyramid tile structure. Steps 1-2 involve encoding and organizing the divided tiles to obtain their geographical extent, and then dividing each tile into grids. The coding organization method is as follows: each tile is coded in the form of hierarchy_row_column to obtain the geographical range of all tiles in the world; The method for dividing each tile into grids is as follows: the geographical area of ​​each tile is evenly divided to obtain an n*n regular grid; the latitude and longitude of each grid point within the tile are calculated from the starting and ending latitude and longitude of the tile, the number of segments n, and the number of rows and columns of the grid point in the grid. Steps 1-3 involve calculating the vertex buffer object and index buffer object based on the divided grid. Specific methods include: In 2D map mode, the planar projection coordinates of the tile grid points are calculated according to the map projection calculation formula; in 3D map mode, the spatial coordinates of the tile grid points are calculated according to the spherical coordinate calculation formula; thus, vertex buffer objects and index buffer objects are obtained. The vertex buffer object and index buffer object are used for switching between two-dimensional display mode and three-dimensional display mode.

3. The integrated two-dimensional and three-dimensional rendering method for situation maps according to claim 2, characterized in that, The basic geographic information data rendering described in step 2 includes the following specific methods: Step 2-1: Obtain grid tiles; Step 2-2, Obtain vector tiles; Steps 2-3: Render the map using raster tiles and vector tiles.

4. The integrated two-dimensional and three-dimensional rendering method for situation maps according to claim 3, characterized in that, The method for obtaining grid tiles in step 2-1 includes: Acquire and process remote sensing image data, sample the remote sensing image data according to the range of Earth tiles, and obtain raster tiles of the corresponding coding organization.

5. The integrated two-dimensional and three-dimensional rendering method for situation maps according to claim 4, characterized in that, The method for obtaining vector tiles described in step 2-2 includes: The process processes vector data by organizing spatial geometric data and multidimensional attribute data into tiles based on a vector tile data model. The tiles are then clipped according to their range to achieve vector tile storage at the point, line, and polygon feature levels, resulting in vector tiles.

6. The integrated two-dimensional and three-dimensional rendering method for situation maps according to claim 5, characterized in that, Steps 2-3 describe rendering the map using raster tiles and vector tiles. The specific methods include: Raster tiles: rendered as the texture of the Earth tiles; Vector tiles: In 2D and 3D modes, the vector elements in the vector tiles are triangulated, submitted to the GPU for rendering, and the vector rendering results are rendered as the texture of the earth tiles.

7. The integrated two-dimensional and three-dimensional rendering method for situation maps according to claim 6, characterized in that, Step 1-1, which describes selecting the top-level tile type based on the projection type, specifically includes: If the projection type is equal latitude and longitude projection, the top tile adopts a 1 row and 2 column format; if the projection type is Mercator projection, the top tile adopts a 1 row and 1 column format.

8. The integrated two-dimensional and three-dimensional rendering method for situation maps according to claim 7, characterized in that, Step 1-1 describes the division of the pyramid tile structure, and the specific method is as follows: Using North latitude as positive values ​​and South latitude as negative values, East longitude as positive values ​​and West longitude as negative values, the global latitude range is -90° to 90° and the longitude range is -180° to 180°. Using an equal latitude and longitude projection method, it is divided into 1*2. Level 0 contains 2 tiles: tile numbered 0_0_0, with a longitude range of -180° to 0° and a latitude range of -90° to 90°, and tile numbered 0_0_1, with a longitude range of 0° to 180° and a latitude range of -90° to 90°. A superior tile is evenly divided into four inferior tiles. That is, the tile numbered 0_0_0 is divided into four tiles numbered 1_0_0, 1_0_1, 1_1_0 and 1_1_1, and the tile numbered 0_0_1 is divided into four tiles numbered 1_0_2, 1_0_3, 1_1_2 and 1_1_3. The lower-level tiles are then divided sequentially.

9. A method for integrated 2D and 3D rendering of a situation map according to claim 8, characterized in that, Step 4, which describes the dynamic switching of the 2D / 3D display mode, includes the following specific methods: Step 4-1: Construct variation models of Earth tiles in two-dimensional and three-dimensional modes. Using Earth tile grid points as the basic unit, determine the spatial position of Earth tile grid points in two-dimensional mode through projection calculation, and determine the spatial position of Earth tile grid points in three-dimensional mode through spherical calculation. Step 4-2: Interpolate the two-dimensional and three-dimensional spatial coordinates of the same Earth tile grid point, establish a calculation formula for the change of grid point coordinates over time, and calculate the spatial position of the Earth tile grid point at each time point frame by frame, with the intersection of the current line of sight and the Earth as the center. Step 4-3: Update the vertex buffer object of the mesh, and represent the smooth change process of mode switching by changing the spatial position of the Earth tile mesh points over a specified time.

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