A method for fusing BIM design terrain and GIS real scene texture

Abstract

The present application relates to the field of BIM model visualization, and particularly relates to a BIM design terrain and GIS real scene texture fusion method, the present application processes BIM design terrain and GIS real scene texture data respectively, when GIS real scene texture data changes, only needs to replace slice data to realize data updating, improves the convenience of data updating, the present application establishes the connection between the image slice node of GIS real scene texture data and the space coordinates of BIM design terrain through coordinate system transformation matrix, is convenient for the coordinate conversion between both, so that the space coordinates of BIM design terrain and the texture coordinates of GIS real scene texture data are corresponded, finally realizes the fusion of BIM design terrain and GIS real scene texture data.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of BIM model visualization, in particular to a BIM design terrain and GIS real scene texture fusion method. BACKGROUND

[0002] BIM design terrain refers to an accurate three-dimensional terrain model created and managed in professional BIM design software. Through terrain editing and terrain analysis, precision, efficiency and sustainability can be achieved in road and path design, drainage system design, building and terrain integration, visualization and digital delivery, etc. GIS real scene texture can be obtained through aerial photography, satellite remote sensing, unmanned aerial photography or laser scanning, and used for visual expression of real ground space information, including raster images, vector maps and oblique photography.

[0003] Since BIM design terrain is generally a single-precision grid model without texture information, there is a problem of missing real scene texture information within the design terrain expression range during the fusion process with multi-source heterogeneous real scene models such as terrain images and oblique photography, which reduces the visualization effect of digital application scenarios. Since real scene texture has high resolution and large volume, directly mapping the design terrain will put a lot of pressure on model loading and rendering, and traditional single texture repeated mapping cannot fully reflect the real real scene texture information, and the visualization effect is not optimized. In the process of editing, analyzing and designing geometric structures, the design terrain will have obvious slope changes.

[0004] There are mainly two ways in the prior art: one is to use orthographic images for vertical projection mapping, which will cause texture stretching and distortion in areas with large slopes or vertical areas; the second is to use a design terrain and LOD (multi-level detail) form real scene texture fusion processing method: referring to the LOD real scene texture generation organization method, the design terrain is processed by blocking, grading and simplifying, etc. This method can solve the problem of loading and rendering of large volume real scene texture, but it will change the original design terrain geometric structure and also cause geometric information redundancy, which will bring difficulties to the analysis and application based on the design terrain. At the same time, the existing technical means do not consider and solve the fusion problem of BIM design terrain and online electronic map and oblique photography texture, and the update problem of GIS real scene texture.

[0005] Therefore, there is an urgent need for a BIM design terrain and GIS real scene texture fusion method to alleviate or even solve the above problems. SUMMARY

[0006] The main objective of this invention is to provide a method for fusing BIM-designed terrain with GIS real-world textures, in order to solve the technical problems of large texture deformation and easy alteration of geometric information when fusing BIM-designed terrain with GIS real-world textures in the prior art.

[0007] To achieve the above objectives, this invention provides a method for fusing BIM-designed terrain with GIS real-world textures, comprising the following steps:

[0008] S1. Obtain the triangular mesh model M and angle threshold of the BIM-designed terrain. According to the angle threshold The triangular mesh model M is divided into n projection directions D. i The triangular mesh model M i Where 0 ≤ i < n, and i is a positive integer;

[0009] S2. Acquire GIS real-scene texture data and the WMTS standard; process the GIS real-scene texture data according to the WMTS standard to obtain multi-resolution image tile data W. i Among them, slice data W i The number of levels is l, and the slice side length is e;

[0010] S3. Determine the triangular mesh model M. i Is it empty and slice data W? i Is it empty? If the triangular mesh model M is empty; i and slice data W i If none of them are empty, proceed to step S4;

[0011] S4. Obtain the coordinate system transformation matrix and slice data W i Image slice node W in layer l ijk According to the projection direction D i Image slice node W ijk Coordinate transformation to triangular mesh model M i The coordinates in the coordinate system; where 0 ≤ j ≤ n k k is the level of the image slice node, n k The number of nodes in the image slice;

[0012] S5, Based on the slice data W i Along the projection direction D i The triangular mesh model M i The mesh is divided into sub-triangular meshes, resulting in model C. ij ;

[0013] S6, Traversal C ijFor each vertex P, the projected coordinates of vertex P are obtained according to the coordinate system transformation matrix. Based on the projected coordinates of vertex P, the position of vertex P in the slice data W is determined. i The corresponding texture coordinates are used to ultimately achieve the fusion of BIM-designed terrain and GIS real-world texture data.

[0014] Furthermore, step S1 specifically includes the following steps:

[0015] By traversing all the triangular faces of the triangular mesh model M, the angle between the normal and the horizontal direction of each triangular face is obtained. The angle between the normal and the positive X-axis According to the angle threshold Angle and included angle The triangular mesh model M is divided into n projection directions D. i The triangular mesh model M i .

[0016] Further, the step of using the angle threshold Angle and included angle The triangular mesh model M is divided into n projection directions D. i The triangular mesh model M i Specifically, it includes the following steps:

[0017] Extract all > The triangular facets form a triangular mesh model M0; extract and or The triangular facets form a triangular mesh model M1; extract and The triangular facets form a triangular mesh model M2; extract and The triangular facets form a triangular mesh model M3; extract and The triangular facets form a triangular mesh model M4; wherein, the projection direction D0 of the triangular mesh model M0 is the positive Z-axis, the projection direction D1 of the triangular mesh model M1 is the positive X-axis, the projection direction D2 of the triangular mesh model M2 is the positive Y-axis, the projection direction D3 of the triangular mesh model M3 is the negative X-axis, and the projection direction D4 of the triangular mesh model M4 is the negative Y-axis.

[0018] Furthermore, step S1 also includes the following steps:

[0019] Obtain the BIM design terrain and determine whether the geographic coordinate system information contained in the BIM design terrain is correct. If it is correct, parse the BIM design terrain into a triangular mesh model M. If it is incorrect, first correct the geographic coordinate system information, and then parse the BIM design terrain into a triangular mesh model M.

[0020] Furthermore, step S2 also includes the following steps:

[0021] For GIS real-scene texture data in the form of oblique photogrammetry: acquire the oblique photogrammetry model, extract the precision 'a' and the triangular mesh model 'M'. i Perpendicular to the projection direction D i The range of plane coordinate values ​​is used to construct raster data;

[0022] Obtain the center point of each raster cell in the raster data, and construct a projection line D parallel to the projection direction using the center point. i The lowest intersection point between the ray and the oblique photography model is obtained;

[0023] Obtain the RGB value of the lowest intersection point, and assign the RGB value of the lowest intersection point to the raster unit corresponding to the ray, thereby obtaining GIS real-scene texture data in the form of a raster image.

[0024] Furthermore, obtaining the coordinate system transformation matrix in step S4 specifically includes the following steps:

[0025] Get slice data W i The coordinates of the top left corner are Resolution a k and slice data W i The index in is Thus, slice data W is obtained. i The coordinates of each pixel in the image are: Thus, the coordinate system transformation matrix is ​​determined:

[0026] Projection direction D i Corresponding spatial coordinates .

[0027] Furthermore, step S6 specifically includes the following steps:

[0028] Get slice data W i top left corner coordinates traversing C ij For each vertex P, the projected coordinates of vertex P are obtained according to the coordinate system transformation matrix. Using formula Obtain vertex P in slice data W i The corresponding texture coordinates Ultimately, this will achieve the integration of BIM-designed terrain with GIS real-world texture data.

[0029] More preferably, after step S6, the following steps are also included:

[0030] Subtriangular mesh model C ij Save as a new triangular mesh model MS i Obtain the sub-triangular mesh model C ij Corresponding slice data W i Texture coordinate results for each layer (UV) ijk ;

[0031] Get slice data W i The file storage path for the sliced ​​data W i File storage path and texture coordinate results UV ijk With sub-triangular mesh model C ij Establish the association, then input the triangular mesh model MS. i In the material and geometric structure data.

[0032] More preferably, the method further includes the following steps:

[0033] Obtain the triangular mesh model MS i The file storage path is used to determine the triangular mesh model MS. i and slice data W i Are the file storage paths of the two the same? If not, then use the triangular mesh model MS. i Stored to the slice data W i Using the same file directory, construct and generate a triangular mesh model MS. i The JSON index file is used to obtain the final fusion result.

[0034] More preferably, the method further includes the following steps:

[0035] Obtain the current GIS real-scene texture data and determine whether the current GIS real-scene texture data has changed; if so, return to step S2 to process the current GIS real-scene texture data and obtain the tile data W of the current multi-resolution image. d The slice data W in step S2 i Replace with W d Proceed to step S3.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] The BIM design terrain and GIS real scene texture data are respectively processed, when the GIS real scene texture data changes, only the slice data needs to be replaced to realize data updating, and the convenience of data updating is improved; the image slice node of the GIS real scene texture data and the spatial coordinates of the BIM design terrain are connected through the coordinate system transformation matrix, the coordinate conversion between the two is facilitated, so that the spatial coordinates of the BIM design terrain and the texture coordinates of the GIS real scene texture data are corresponded, and finally the fusion of the BIM design terrain and the GIS real scene texture data is realized. BRIEF DESCRIPTION OF DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only show some of the embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from the structures shown in the drawings without creative labor.

[0039] Figure 1 The flowchart of the fusion method of the BIM design terrain and the GIS real scene texture in an embodiment of the present application.

[0040] The object implementation, functional characteristics and advantages of the present application will be further described with reference to the embodiments and the drawings. DETAILED DESCRIPTION

[0041] It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0042] The technical solutions in the embodiments of the present application will be described clearly and completely with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0043] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative positional relationship, motion condition, etc. between components in a certain posture (as described in the drawings), if the certain posture changes, the directional indications also change accordingly.

[0044] In addition, the description related to "first", "second" and the like in the present application is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implying the number of the indicated technical features. Therefore, the features defined as "first", "second" can be explicitly or implicitly included at least one of the features. In addition, the technical solutions of various embodiments can be combined with each other, but it must be based on the realization of ordinary skilled in the art, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, also not within the protection scope required by the present application.

[0045] Please refer to Figure 1 , the embodiment provides a kind of fusion method of BIM design topography and GIS real scene texture, comprising the following steps:

[0046] S1, the triangular mesh model M of BIM design topography and angle threshold value are acquired According to the angle threshold value The triangular mesh model M is divided into n triangular mesh models M i With D i As projection direction;Wherein, 0≤i<n, i is positive integer.

[0047] Specifically, BIM design topography is acquired, whether the geographic coordinate system information contained in BIM design topography is correct is judged;If correct, BIM design topography is parsed into triangular mesh model M;If not correct, first correct the geographic coordinate system information, then BIM design topography is parsed into triangular mesh model M.Each design platform BIM model can be parsed based on its own tool or secondary development interface, such as Bentley platform can be based on MDL development to realize the correct and complete parsing of BIM model related information.

[0048] All triangular facets of the triangular mesh model M are traversed, to get the included angle Between normal and horizontal direction and the included angle Between normal and X axis positive direction;Wherein, the included angle Take anticlockwise positive value, the included angle Take acute angle positive value, and the relationship between slope Is: According to the angle threshold value , included angle And included angle The triangular mesh model M is divided into 5 triangular mesh models M i With D i As projection direction: all triangular facets of > Are extracted to form triangular mesh model M0;Extract And or triangles of the triangular mesh model M1; extracting and triangles of the triangular mesh model M2; extracting and triangles of the triangular mesh model M3; extracting and triangles of the triangular mesh model M4; wherein the projection direction D0 of the triangular mesh model M0 is the Z-axis positive direction, the projection direction D1 of the triangular mesh model M1 is the X-axis positive direction, the projection direction D2 of the triangular mesh model M2 is the Y-axis positive direction, the projection direction D3 of the triangular mesh model M3 is the X-axis negative direction, and the projection direction D4 of the triangular mesh model M4 is the Y-axis negative direction.

[0049] S2, acquiring GIS real scene texture data and WMTS standard, processing the GIS real scene texture data according to the WMTS standard to obtain slice data W i .

[0050] The GIS real scene texture data includes grid images, vector maps, and oblique photography, etc. forms. The GIS real scene texture data in the form of grid images and vector maps can be directly sliced through the WMTS standard. However, the prior art is difficult to fuse the GIS real scene texture data in the form of oblique photography with the BIM design terrain.

[0051] In the embodiment, for the GIS real scene texture data in the form of oblique photography: acquiring an oblique photography model, extracting a precision a and a triangular mesh model M i perpendicular to the projection direction D i , so as to create a grid data with a resolution of a, a width of w, a height of h and a band number of 4 based on the GDAL library; wherein the plane coordinate value range is a rectangular range with a length of w and a width of h;

[0052] Acquiring a center point of each grid unit in the grid data, constructing a ray parallel to the projection direction D i with the center point, to obtain the lowest intersection point of the ray and the oblique photography model;

[0053] Acquiring the RGB value of the lowest intersection point, and assigning the RGB value of the lowest intersection point to the grid unit corresponding to the ray, so as to obtain the GIS real scene texture data in the form of grid images, thereby facilitating the processing of the WMTS standard.

[0054] It is worth noting that for GIS real-world texture data in the form of raster images that do not conform to the WMTS standard set by OGC, third-party software or tools, such as CesiumLab, Cesium Terrain Builder, SuperMap, and ArcGIS, can be directly processed into WMTS-compliant tile data W0; wherein, the tile data W0 corresponds to the triangular mesh model M0 of the projection direction D0 in step 2.

[0055] S3. Determine the triangular mesh model M. i Is it empty and slice data W? i Is it empty? If the triangular mesh model M is empty; i and slice data W i If none of them are empty, proceed to step S4.

[0056] S4. Obtain the coordinate system transformation matrix and slice data W i Image slice node W in layer l ijk According to the projection direction D i The image slice node W is transformed using the coordinate system transformation matrix. ijk Coordinate transformation to triangular mesh model M i The coordinates in the coordinate system; where 0 ≤ j ≤ n k k is the level of the image slice node, n k The number of image tile nodes, and the tile data W. i The number of levels is l, and the slice data is W. i The side length of the slice is e.

[0057] Specifically, obtain slice data W i The coordinates of the top left corner are Resolution a k and slice data W i The index in is Thus, slice data W is obtained. i The coordinates of each pixel in the image are: Thus, the coordinate system transformation matrix is ​​determined:

[0058] Projection direction D i Corresponding spatial coordinates .

[0059] Traversing C ij For each vertex P, the projected coordinates of vertex P are obtained according to the coordinate system transformation matrix. Using formula Obtain vertex P in slice data W i The corresponding texture coordinates Ultimately, this will achieve the integration of BIM-designed terrain with GIS real-world texture data.

[0060] S5, Based on the slice data W i Along the projection direction D i The triangular mesh model M i The mesh is divided into sub-triangular meshes, resulting in model C. ij .

[0061] S6, Traversing Subtriangular Mesh Model C ij For each vertex P, the projected coordinates of vertex P are obtained according to the coordinate system transformation matrix. Based on the projected coordinates of vertex P, the position of vertex P in the slice data W is determined. i The corresponding texture coordinates are used to ultimately achieve the fusion of BIM-designed terrain and GIS real-world texture data.

[0062] In one embodiment, the subtriangular mesh model C ij Save as a new triangular mesh model MS i Obtain the sub-triangular mesh model C ij Corresponding slice data W i Texture coordinate results for each layer (UV) ijk ;

[0063] Get slice data W i The file storage path for the sliced ​​data W i File storage path and texture coordinate results UV ijk With sub-triangular mesh model C ij Establish the association, then input the triangular mesh model MS. i In the material and geometric structure data.

[0064] Obtain the triangular mesh model MS i The file storage path is used to determine the triangular mesh model MS. i and slice data W i Are the file storage paths of the two the same? If not, then use the triangular mesh model MS. i Stored to the slice data W i Using the same file directory, construct and generate a triangular mesh model MS. i The JSON index file is used to obtain the final fusion result.

[0065] Obtain the current GIS real-scene texture data and determine whether the current GIS real-scene texture data has changed; if so, return to step S2 to process the current GIS real-scene texture data and obtain the tile data W of the current multi-resolution image. d The slice data W in step S2 i Replace with W d Proceed to step S3.

[0066] The method of the embodiment supports the fusion processing of multi-source GIS real scene textures such as raster images, vector maps and oblique photography; the method applies the slope to the BIM design terrain and GIS real scene texture processing, improves the fusion visualization effect; the method separates and stores the geometry file and the texture file, provides a convenient and effective updating mechanism for GIS real scene texture; the method uses the single-precision triangular mesh model combined with the multi-resolution texture for data organization, improves the loading and rendering efficiency; the method only cuts the BIM design terrain, and the coordinates, positions and geometric modeling do not change, which meets the accurate analysis and application based on the BIM design terrain.

[0067] Embodiment

[0068] The BIM design terrain of a certain project is parsed into a triangular mesh model and output as an OBJ file by secondary development with the Bentley platform MicroStation Connect Edition Update 16 and MicroStation CONNECT Edition SDK, and the geographic coordinate system information is parsed as CGCS2000 / 3-degree Gauss-Kruger CM 108E (EPSG: 4545).

[0069] The angle threshold is set to 0°, the OBJ model is divided into two triangular meshes A and B with the projection directions of Z-axis positive direction and X-axis negative direction respectively by calculating and judging the value range of the included angle between the normal of each triangular facet and the horizontal plane and the X-axis;

[0070] The extraction accuracy of oblique photography is set to 10 cm, the projection ranges of A and B are calculated, and Tiff raster R A and R B are respectively created based on the GDAL library, and each raster cell value is further calculated and stored in combination with oblique photography.

[0071] The image slicing function of CesiumLab software (version 3.1) is used, the service type is set to WMTS, the tile size is set to 256, and R A and R B are respectively processed in the Mercator projection mode to obtain a total of 6 levels of image slicing results and (due to only a single node below 15, the slicing results from 0 to 14 are deleted, and only the slicing data of 6 levels from 15 to 20 are reserved);

[0072] and and The 6th level grid slice result is cut from the Z-axis direction and the X-axis direction based on the CGAL library to obtain new triangular meshes A and B after the coordinate range of a single slice is calculated according to the WMTS encoding rule and the coordinates are converted and ;

[0073] The UV coordinates of each sub-grid in the 6 level image slices in and are calculated and updated, and the relative path information of the slice texture is constructed. The UV coordinates of each sub-grid in the 6 level image slices in are calculated and updated, and the relative path information of the slice texture is constructed.

[0074] The JSON index file containing and is constructed, and the fusion result is organized.

[0075] The above is only the preferred embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent structure or equivalent process transformation using the content of the 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.

Claims

1. A method for fusing BIM design terrain with GIS real scene texture, characterized in that, The method comprises the following steps: S1. Obtain the triangular mesh model M and angle threshold of the BIM-designed terrain. According to the angle threshold The triangular mesh model M is divided into n projection directions D. i The triangular mesh model M i Where 0 ≤ i < n, and i is a positive integer; S2, acquire GIS real scene texture data and WMTS standard, slice the GIS real scene texture data according to the WMTS standard, and obtain slice data W of multi-resolution image i ; S3, judging whether the triangular mesh model M i is empty or not, and judging whether the slice data W i is empty or not; if the triangular mesh model M i and the slice data W i are both not empty, then entering step S4; S4, obtaining a coordinate system transformation matrix and slice data W i of the image slice node W ijk , according to the projection direction D i , converting the coordinates of the image slice node W ijk to coordinates in the coordinate system of the triangular mesh model M i through the coordinate system transformation matrix; wherein 0≤j≤n k , k is the level where the image slice node is located, n k is the number of image slice nodes; S5、according to the slice data W i along the projection direction D i the triangular mesh model M i is divided to obtain a divided sub-triangular mesh model C ij ; S6, traversing the sub-triangle mesh model C ij For each vertex P, a projection coordinate of the vertex P is obtained according to the coordinate system transformation matrix, and a corresponding texture coordinate of the vertex P on the slice data W i is determined according to the projection coordinate of the vertex P, so as to realize the fusion of the BIM design terrain and the GIS real scene texture data. Wherein, the step S1 according to the angle threshold The triangular mesh model M is divided into n projection directions D i The triangular mesh model M i , specifically comprising the following steps: traverse all the triangular facets of the triangular mesh model M, get the included angle between the normal of each triangular facet and the horizontal direction , and the included angle between the normal and the positive direction of the X axis ; according to the angle threshold , the included angle , and the included angle , the triangular mesh model M is divided into n triangular mesh models M i with projection direction D i ; Extract all > The triangular facets form a triangular mesh model M0; extract and or The triangular facets form a triangular mesh model M1; extract and The triangular facets form a triangular mesh model M2; extract and The triangular facets form a triangular mesh model M3; extract and The triangular facets form a triangular mesh model M4; wherein, the projection direction D0 of the triangular mesh model M0 is the positive Z-axis, the projection direction D1 of the triangular mesh model M1 is the positive X-axis, the projection direction D2 of the triangular mesh model M2 is the positive Y-axis, the projection direction D3 of the triangular mesh model M3 is the negative X-axis, and the projection direction D4 of the triangular mesh model M4 is the negative Y-axis.

2. The method of claim 1, wherein, The step S1 of obtaining the triangular mesh model M of the BIM design terrain specifically comprises the following steps: Obtaining the BIM design terrain, judging whether the geographic coordinate system information contained in the BIM design terrain is correct; if yes, the BIM design terrain is parsed into the triangular mesh model M; if not, the geographic coordinate system information is first corrected, and then the BIM design terrain is parsed into the triangular mesh model M.

3. The method of claim 1, wherein, In the step S2, for the GIS real scene texture data in the form of oblique photography, the following steps are further included: For GIS real scene texture data in the form of oblique photography: obtaining an oblique photography model, extracting precision a and a triangular mesh model M i The plane coordinates perpendicular to the projection direction D i are in the value range, so as to construct the grid data; obtaining a center point of each grid unit in the grid data, constructing a ray parallel to the projection direction D i with the center point, obtaining the lowest intersection point of the ray and the oblique photography model; Obtaining the RGB value of the lowest intersection point, and assigning the RGB value of the lowest intersection point to the grid unit corresponding to the ray, so as to obtain the GIS real scene texture data in the form of a grid image.

4. The method of claim 1, wherein, The step S4 of obtaining the coordinate system transformation matrix specifically comprises the following steps: Obtaining slice data W i The upper-left corner coordinate of slice data W , resolution a k and the index in slice data W i is , so as to obtain the coordinate of each pixel point in slice data W i is , so as to determine the coordinate system transformation matrix: Projection direction D i Corresponding spatial coordinates .

5. The method of claim 1, wherein, The step S6 specifically comprises the following steps: Get slice data W i top left corner coordinates traversing C ij For each vertex P, the projected coordinates of vertex P are obtained according to the coordinate system transformation matrix. Using formula Obtain vertex P in slice data W i The corresponding texture coordinates Ultimately, this achieves the fusion of BIM-designed terrain and GIS real-world texture data; among which, the tile data W i The side length of the slice is e.

6. The method of claim 5, wherein, The step S6 further comprises the following steps: Sub-triangle mesh model C is obtained ij stored as new triangle mesh model MS i Sub-triangle mesh model C is obtained ij corresponding slice data W i texture coordinate results UV of each level ijk ; Acquire slice data W i , and store the file storage path of slice data W i , and store the file storage path of slice data W ijk and texture coordinate result UV ij , and associate with sub-triangle mesh model C i , and input the material and geometry data of triangle mesh model MS 7. The method of claim 6, wherein, The step S6 further comprises the following steps: Obtaining a file storage path of the triangular mesh model MS i , judging whether the file storage paths of the triangular mesh model MS i and the slice data W i are same; if not, storing the triangular mesh model MS i to the same file directory as the slice data W i , constructing a JSON index file of the triangular mesh model MS i to obtain a final fusion result.

8. The method of claim 1, wherein, The step S6 further comprises the following steps: The step S6 further comprises the following steps: Obtaining current GIS real scene texture data, judging whether the current GIS real scene texture data has change; if yes, returning to step S2, processing the current GIS real scene texture data to obtain slice data W of current multi-resolution image d , of step S2 i is replaced by W d , and entering step S3.

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