Method for constructing digital twin simulation engine fusing GIS engine and game engine

Abstract

The application discloses a digital twin simulation engine construction method fusing a GIS engine and a game engine, and realizes fusion of a GIS rendering pipeline and a game engine rendering pipeline through construction of a multi-source heterogeneous data loading and rendering technology weakly coupled with a rendering pipeline, so that massive multi-source heterogeneous data loading fusion is supported, different rendering pipelines can be switched, game scene direct loading is supported, and the multi-source heterogeneous data loading problem that neither the GIS engine nor the game engine has is solved, different rendering pipelines, especially the rendering pipeline of the game engine, are compatible, and bottom support is provided for high-fidelity rendering. The application also solves the contradiction between the GIS engine supporting large-volume image terrain data loading but poor in rendering quality and the game engine terrain system being perfect in rendering quality but without geographical information attributes and being unable to bear large-volume terrain data loading.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of digital twin simulation engine, and in particular to a digital twin simulation engine construction method fusing GIS engine and game engine. BACKGROUND

[0002] The development of a digital twin project is usually based on a digital twin simulation engine. Currently, there are three main types of digital twin engines in the industry: GIS engines represented by Cesium and SuperMap, game engines represented by UE (Unreal) and Unity, and conventional webgl engines represented by three.js. Each of the three engines has different applications. GIS engines naturally support ellipsoidal coordinate systems and have strong spatial analysis capabilities, but the scene rendering quality is generally poor. Game engines have high-quality rendering pipelines and can support high-fidelity three-dimensional scene building, but they lack GIS-related capabilities. Webgl engines are relatively lightweight and easy to integrate, but their rendering quality is generally poor and they do not support GIS functions.

[0003] Most digital twin project designs in China currently require certain spatial analysis functions (GIS functions) and high-fidelity three-dimensional scene building and rendering. To meet these requirements, GIS engines and game engines are usually used together to build GIS scenes and high-fidelity game scenes, respectively. While this solution meets project requirements, it also causes scene separation, high development costs, and complex integration. SUMMARY

[0004] The present application aims to provide a digital twin simulation engine construction method fusing GIS engine and game engine, which aims to solve the problem of needing to build GIS scenes and high-fidelity scenes separately in digital twin projects.

[0005] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0006] The digital twin simulation engine construction method fusing GIS engine and game engine according to the present application comprises the following steps:

[0007] S1, constructing a coordinate fusion system of ellipsoidal coordinate system in GIS engine and plane coordinate system in game engine;

[0008] S2, constructing a terrain system including terrain data loading, image data loading, vegetation rendering, and dynamic terrain editing;

[0009] S3, constructing a multi-source heterogeneous data loading and rendering technology with weak coupling to the rendering pipeline, to realize the fusion of GIS rendering pipeline and game engine rendering pipeline;

[0010] S4, load game scene.

[0011] Further, the S1 step comprises:

[0012] S1.1, construct a three-dimensional space plane coordinate system in Cartesian coordinate system, with unit set as meters;

[0013] S1.2, construct an ellipsoid coordinate system based on the ellipsoid parameters of the WGS-84 coordinate system;

[0014] S1.3, construct a coordinate conversion algorithm between the ellipsoid coordinate system and the plane coordinate system based on the ellipsoid parameters of the WGS-84 coordinate system.

[0015] Further, the terrain data and the image data are scheduled and managed in a tile quadtree structure; the terrain data loading comprises reading elevation data of the terrain data, modifying the surface grid structure of the corresponding latitude and longitude coordinates in the ellipsoid coordinate system according to the elevation data, and realizing the real terrain structure; the image data loading comprises mapping the image data as texture to the surface grid structure of the corresponding latitude and longitude coordinates in the corresponding ellipsoid coordinate system, and realizing the real terrain appearance.

[0016] Further, the image data loading further comprises generating a normal map according to the image data to enhance the details of the terrain appearance.

[0017] Further, the vegetation rendering comprises using the billboarding technology, using 2D texture to construct quadrilaterals to simulate vegetation, and loading three-dimensional vegetation models.

[0018] Further, the state terrain editing comprises obtaining user input parameters, modifying the surface grid structure of the corresponding latitude and longitude coordinates in the ellipsoid coordinate system, and calculating image texture mapping and vegetation position.

[0019] Further, the S3 step comprises vector graphic ground rendering, vector graphic model rendering, and BIM high-fidelity rendering, and the rendering process is divided into a data analysis and preprocessing module, a rendering data construction module, and a rendering pipeline module; the data analysis and preprocessing module converts multi-source heterogeneous data into the required rendering data format; the rendering data construction module constructs rendering data into geometric bodies, textures, and lighting data required by the rendering pipeline according to rendering requirements; and the rendering pipeline module is used to select the rendering pipeline of the digital twin simulation simulation engine according to the rendering data type.

[0020] Further, the S4 step of loading the game scene comprises depth fusion loading and coordinate compatible loading; the depth fusion loading converts the game engine terrain into a digital twin simulation simulation terrain under the ellipsoid coordinate system; and the coordinate compatible loading is suitable for game scenes that can only run under the plane coordinate system, and retains the original running mode and rendering effect of the game scene in the digital twin simulation simulation.

[0021] The advantage of the present application is that by constructing a multi-source heterogeneous data loading and rendering technology weakly coupled with a rendering pipeline, the fusion of the GIS rendering pipeline and the game engine rendering pipeline is realized, which not only supports the loading and fusion of massive multi-source heterogeneous data, but also supports switching different rendering pipelines and directly loading game scenes, solves the multi-source heterogeneous data loading problem that neither the GIS engine nor the game engine has, and is compatible with different rendering pipelines, especially the rendering pipeline of the game engine, which provides bottom support for high-fidelity rendering.

[0022] The present application also fuses the image terrain loading method of the GIS engine + the vegetation rendering and dynamic terrain editing capability of the game engine, constructs a terrain system that can carry large amount of data and has high-quality and high-fidelity rendering effect, and in combination with the construction of the ellipsoidal coordinate system, can provide bottom geographic information data support for various high-precision spatial analysis functions, and solve the contradiction between the GIS engine supporting large amount of image terrain data loading but having poor rendering quality and the game engine terrain system being perfect and having high rendering quality but having no geographic information attribute and being unable to carry large amount of terrain data loading.

[0023] Therefore, the present application constructs a digital twin simulation simulation engine with high-fidelity rendering, massive multi-source heterogeneous data fusion, high-precision spatial analysis and other capabilities, so that projects that have both GIS function requirements and high-fidelity scene building requirements save technical cost and labor cost compared with existing solutions. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The present application is described as a fusion GIS engine and game engine digital twin simulation simulation engine construction method flow chart. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present application will be described below in a clear and complete manner. Obviously, the described embodiments are only a part 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 fall within the scope of the present application.

[0026] The fusion GIS engine and game engine digital twin simulation simulation engine construction method described in the present application, as shown in Figure 1 includes the following steps:

[0027] S1, construct a coordinate fusion system of the ellipsoidal coordinate system in the GIS engine and the plane coordinate system in the game engine, to realize accurate matching of the ellipsoidal coordinate system in the GIS engine and the plane coordinate system in the game engine. The plane coordinate system described in the present application is a conventional three-dimensional coordinate system that is not spherical.

[0028] The specific steps are:

[0029] S1.1, using a Cartesian coordinate system, the unit is set to meters, a three-dimensional space plane coordinate system is constructed;

[0030] S1.2, based on the ellipsoid parameters of the WGS-84 coordinate system, an ellipsoid coordinate system is constructed;

[0031] S1.3, based on the ellipsoid parameters of the WGS-84 coordinate system, the coordinate conversion algorithm of the ellipsoid coordinate system and the plane coordinate system is constructed.

[0032] S2, a terrain system including terrain data loading, image data loading, vegetation rendering, and dynamic terrain editing is constructed to realize the functional integration of the terrain in the GIS engine and the terrain in the game engine.

[0033] The terrain data and the image data are scheduled and managed in the tile quadtree structure commonly used in the GIS engine. The loading method of the terrain data is to read the elevation data of the terrain data, modify the surface grid structure of the corresponding latitude and longitude coordinates in the ellipsoid coordinate system according to the read elevation data, and realize the real terrain structure. The loading method of the image data is to map the image data as a texture to the surface grid structure corresponding to the latitude and longitude coordinates in the corresponding ellipsoid coordinate system, and realize the real appearance of the terrain. The loading of the image data also includes generating a normal map to enhance the details of the terrain appearance according to the image data.

[0034] The vegetation rendering includes using the billboarding technology to construct quadrilaterals using 2D textures to simulate vegetation and directly loading three-dimensional vegetation models. Among them, the vegetation rendering quality of using 2D textures to construct quadrilaterals and real-time orientation to the camera to simulate vegetation is detailed, while the direct loading of three-dimensional vegetation models has high rendering quality, but the calculation and storage overhead is high. According to different application scenarios and needs, appropriate ways can be selected for vegetation rendering, and at the same time, the LOD (Level of Detail) technology can be combined to optimize the loading method of the three-dimensional vegetation model.

[0035] The dynamic terrain editing is realized based on the dynamic terrain editing algorithm, that is, by obtaining user operations as input parameters, the surface grid structure corresponding to the latitude and longitude coordinates in the ellipsoid coordinate system is modified, such as height adjustment, terrain shaping based on brush shape, etc. When the terrain is modified, the image texture map and the vegetation position are automatically recalculated.

[0036] S3, a multi-source heterogeneous data loading and rendering technology weakly coupled with the rendering pipeline, realizes the fusion of GIS rendering pipeline and game engine rendering pipeline, including vector graphics ground rendering, vector graphics model rendering, BIM high-fidelity rendering. The specific rendering process is divided into data analysis and preprocessing module, rendering data construction module, rendering pipeline module. The data analysis and preprocessing module converts multi-source heterogeneous data (including vector data, terrain & image data, oblique photography, point cloud data, BIM data and FBX, OBJ and other formats of conventional three-dimensional model data) into the required rendering data format; the rendering data construction module constructs the rendering data into the geometry, texture and lighting data required by the rendering pipeline according to the rendering requirements (such as terrain, building, city model, etc.); the rendering pipeline module selects the appropriate rendering pipeline to complete the rendering according to different rendering data formats, ensures the efficiency and accuracy in the rendering process, so as to realize the weak coupling of data loading, rendering and rendering pipeline. At the same time, combined with the efficient encoding compression technology of triangular mesh and the scheduling algorithm of CPU-GPU heterogeneous parallel computing to improve the loading and rendering efficiency.

[0037] S4, the loading of game scene includes depth fusion loading and coordinate compatible loading. The depth fusion loading converts the terrain of game engine into digital twin simulation terrain under the ellipsoid coordinate system. The coordinate compatible loading is suitable for game scenes that can only run in the plane coordinate system, and retains the original running mode and rendering effect of the game scene in the digital twin simulation.

Claims

1. A method for constructing a digital twin simulation engine that fuses a GIS engine and a game engine, the method comprising: receiving a digital twin simulation engine request; determining a digital twin simulation engine based on the digital twin simulation engine request; and providing the digital twin simulation engine to a user. It comprises the following steps: S1, constructing a coordinate fusion system of the ellipsoidal coordinate system in the GIS engine and the plane coordinate system in the game engine; Specifically comprising: S1.1, using the Cartesian coordinate system, setting the unit as meters, and constructing a three-dimensional space plane coordinate system; S1.2, constructing an ellipsoidal coordinate system based on the ellipsoidal parameters of the WGS-84 coordinate system; S1.3, constructing a coordinate conversion algorithm of the ellipsoidal coordinate system and the plane coordinate system based on the ellipsoidal parameters of the WGS-84 coordinate system; S2, constructing a terrain system including terrain data loading, image data loading, vegetation rendering, and dynamic terrain editing; S3, constructing a multi-source heterogeneous data loading and rendering technology weakly coupled with the rendering pipeline, realizing the fusion of the GIS rendering pipeline and the game engine rendering pipeline; Specifically including vector graphic ground rendering, vector graphic model rendering, BIM high-fidelity rendering; The rendering process is divided into a data analysis and preprocessing module, a rendering data construction module, and a rendering pipeline module; The data analysis and preprocessing module converts multi-source heterogeneous data into the required rendering data format; The rendering data construction module constructs the rendering data into geometric bodies, textures, and lighting data required by the rendering pipeline according to the rendering requirements; The rendering pipeline module is used to select the appropriate rendering pipeline according to the rendering data format; S4, loading the game scene.

2. The method according to claim 1, wherein the method is characterized in that: The terrain data and the image data are scheduled and managed in a tile quadtree structure; The terrain data loading includes reading the elevation data of the terrain data, modifying the surface grid structure of the corresponding latitude and longitude coordinates in the ellipsoidal coordinate system according to the elevation data, and realizing the real terrain structure; The image data loading includes mapping the image data as a texture to the surface grid structure corresponding to the latitude and longitude coordinates in the corresponding ellipsoidal coordinate system, realizing the real terrain appearance.

3. The method of claim 2, wherein the method further comprises: receiving a request to create a digital twin simulation of a game; and creating the digital twin simulation of the game. The image data loading also includes generating a normal map to enhance the details of the terrain appearance according to the image data.

4. The method of claim 1, wherein the method further comprises: The vegetation rendering includes using the billboarding technology to construct quadrilaterals to simulate vegetation and load three-dimensional vegetation models using 2D textures.

5. The method of claim 1, wherein the method further comprises: The dynamic terrain editing includes obtaining user input parameters, modifying the surface grid structure of the corresponding latitude and longitude coordinates in the ellipsoidal coordinate system, and calculating the image texture mapping and vegetation position.

6. The method according to claim 1, wherein the method is characterized in that: The game scene loading in S4 includes deep fusion loading and coordinate compatible loading; The deep fusion loading converts the game engine terrain into a digital twin simulation terrain under the ellipsoidal coordinate system; The coordinate compatible loading is suitable for game scenes that can only run under the plane coordinate system, and retains the original running mode and rendering effect of the game scene in the digital twin simulation.

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