Digital twin analog simulation engine construction method fusing GIS engine and game engine

Abstract

The invention discloses a digital twin analog simulation engine construction method fusing a GIS engine and a game engine, and the method achieves the fusion of a GIS rendering pipeline and a game engine rendering pipeline through constructing a multi-source heterogeneous data loading and rendering technology which is weakly coupled with the rendering pipeline. The method not only supports loading and fusion of massive multi-source heterogeneous data, but also supports switching of different rendering pipelines and direct loading of game scenes, solves the problem of multi-source heterogeneous data loading which neither a GIS engine nor a game engine, is also compatible with different rendering pipelines, especially the rendering pipelines of the game engine, and is suitable for large-scale application. And a bottom layer support is provided for high-fidelity rendering. The method also solves the contradictions that the GIS engine supports large-volume image topographic data loading but the rendering quality is poor, and the game engine topographic system is perfect, the rendering quality is high, no geographic information attribute exists, and large-volume topographic data loading cannot be borne.

Description

Technical Field

[0001] The present invention relates to the technical field of digital twin simulation engines, and in particular to a method for constructing a digital twin simulation engine that integrates a GIS engine and a game engine. Background Art

[0002] The development of digital twin projects is usually based on digital twin simulation engines. Currently, there are three types of digital twin engines available 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. These three are applicable in different situations. The GIS engine naturally supports the ellipsoidal coordinate system and has powerful spatial analysis capabilities, but the scene rendering quality is average. The game engine has a high-quality rendering pipeline that can support the construction of high-fidelity three-dimensional scenes, but the GIS-related capabilities are insufficient. The webgl engine is relatively lightweight and easy to integrate, but the rendering quality is average and does not support GIS functions.

[0003] At present, most digital twin project designs in China require certain spatial analysis functions (GIS functions) and the construction and rendering of high-fidelity three-dimensional scenes. To meet the above requirements, the GIS engine and the game engine are usually used together when selecting a digital twin engine to build GIS scenes and high-fidelity game scenes respectively. Although this solution meets the project requirements, it also causes problems such as scene separation, high development costs, and complex integration. Summary of the invention

[0004] The purpose of the present invention is to provide a method for constructing a digital twin simulation engine that integrates a GIS engine and a game engine, aiming to solve the problem of needing to separately construct a GIS scene and a high-fidelity scene in a digital twin project.

[0005] To achieve the above object, the present invention adopts the following technical solutions: The method for constructing a digital twin simulation engine integrating a GIS engine and a game engine according to the present invention comprises the following steps: S1, construct the coordinate fusion system of the ellipsoid coordinate system in the GIS engine and the plane coordinate system in the game engine; S2, build a terrain system including terrain data loading, image data loading, vegetation rendering, and dynamic terrain editing; S3, builds multi-source heterogeneous data loading and rendering technology that is weakly coupled with the rendering pipeline, and realizes the integration of GIS rendering pipeline and game engine rendering pipeline; S4, load the game scene.

[0006] Furthermore, step S1 includes: S1.1, using Cartesian coordinate system, with the unit set to meters, to construct a three-dimensional space plane coordinate system; S1.2, construct an ellipsoid coordinate system based on the ellipsoid parameters of the WGS-84 coordinate system; S1.3, construct the coordinate conversion algorithm between the ellipsoid coordinate system and the plane coordinate system based on the ellipsoid parameters of the WGS-84 coordinate system.

[0007] Furthermore, 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, and modifying the surface grid structure of the corresponding longitude and latitude coordinates in the ellipsoid coordinate system according to the elevation data to achieve a real terrain structure; the image data loading includes mapping the image data as a texture to the surface grid structure of the corresponding longitude and latitude coordinates in the ellipsoid coordinate system to achieve a real terrain appearance.

[0008] Furthermore, the image data loading also includes generating a normal map based on the image data to enhance the details of the terrain appearance.

[0009] Furthermore, the vegetation rendering includes using billboarding technology, utilizing 2D textures to construct quadrilaterals to simulate vegetation, and loading a three-dimensional vegetation model.

[0010] Furthermore, the dynamic terrain editing includes obtaining user input parameters, modifying the surface grid structure corresponding to the longitude and latitude coordinates in the ellipsoidal coordinate system, and calculating the image texture map and vegetation position.

[0011] Furthermore, step S3 includes vector graphics ground rendering, vector graphics model rendering, and BIM high-fidelity rendering. The rendering process is decomposed into a data parsing and preprocessing module, a rendering data construction module, and a rendering pipeline module; the data parsing and preprocessing module converts multi-source heterogeneous data into the required rendering data format; the rendering data construction module constructs the rendering data into the geometry, texture, and lighting data required for the rendering pipeline according to the rendering requirements; the rendering pipeline module is used to select the rendering pipeline of the digital twin simulation engine according to the rendering data type.

[0012] Furthermore, step S4 of game scene loading includes deep fusion loading and coordinate compatible loading. The deep fusion loading converts the game engine terrain into a digital twin simulation terrain in an ellipsoidal coordinate system. The coordinate compatible loading is suitable for game scenes that can only be run in a plane coordinate system, and retains the original running mode and rendering effect of the game scene in the digital twin simulation.

[0013] The advantage of the present invention is that by constructing a multi-source heterogeneous data loading and rendering technology that is weakly coupled with the rendering pipeline, the fusion of the GIS rendering pipeline and the game engine rendering pipeline is realized. It not only supports the loading and fusion of massive multi-source heterogeneous data, but also supports switching between different rendering pipelines and supports direct loading of game scenes. It solves the multi-source heterogeneous data loading problem that neither the GIS engine nor the game engine itself has, and is also compatible with different rendering pipelines, especially the rendering pipeline of the game engine, providing underlying support for high-fidelity rendering.

[0014] The present invention also integrates the image terrain loading method of the GIS engine + the vegetation rendering and dynamic terrain editing capabilities of the game engine, and constructs a terrain system that can carry large amounts of data and has high-quality and high-fidelity rendering effects. Combined with the construction of the ellipsoidal coordinate system, it can provide underlying geographic information data support for various high-precision spatial analysis functions, solving the contradictions of "the GIS engine supports the loading of large amounts of image terrain data but the rendering quality is poor" and "the game engine has a complete terrain system with high rendering quality but no geographic information attributes and cannot carry the loading of large amounts of terrain data".

[0015] Therefore, the present invention constructs a digital twin simulation engine with multiple capabilities such as high-fidelity rendering, massive multi-source heterogeneous data fusion, and high-precision spatial analysis, which saves technical and labor costs compared to existing solutions for projects that have both GIS functional requirements and high-fidelity scene construction requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a flow chart of the method for constructing a digital twin simulation engine that integrates a GIS engine and a game engine as described in the present invention. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] The method for constructing a digital twin simulation engine integrating a GIS engine and a game engine described in the present invention is as follows: Figure 1 As shown, the following steps are included: S1, constructing a coordinate fusion system of the ellipsoid coordinate system in the GIS engine and the plane coordinate system in the game engine to achieve accurate matching of the ellipsoid coordinate system in the GIS engine and the plane coordinate system in the game engine. The plane coordinate system in the present invention is a conventional three-dimensional coordinate system of an aspherical surface.

[0019] The specific steps are: S1.1, using Cartesian coordinate system, with the unit set to meters, to construct a three-dimensional space plane coordinate system; S1.2, construct an ellipsoid coordinate system based on the ellipsoid parameters of the WGS-84 coordinate system; S1.3, construct the coordinate conversion algorithm between the ellipsoid coordinate system and the plane coordinate system based on the ellipsoid parameters of the WGS-84 coordinate system.

[0020] S2, builds a terrain system including terrain data loading, image data loading, vegetation rendering, and dynamic terrain editing to achieve functional integration of terrain in GIS engine and terrain in game engine.

[0021] The terrain data and the image data are scheduled and managed using a tile quadtree structure commonly used in GIS engines. The terrain data is loaded in a manner that, after reading the elevation data of the terrain data, the surface grid structure corresponding to the longitude and latitude coordinates in the ellipsoid coordinate system is modified according to the read elevation data to achieve a real terrain structure. The image data is loaded in a manner that the image data is mapped as a texture to the surface grid structure corresponding to the longitude and latitude coordinates in the ellipsoid coordinate system to achieve a real terrain appearance. The loading of the image data also includes generating a normal map based on the image data to enhance the details of the terrain appearance.

[0022] The vegetation rendering includes using billboarding technology, using 2D textures to construct quadrilaterals to simulate vegetation, and directly loading three-dimensional vegetation models. Among them, the vegetation rendering quality of using 2D textures to construct quadrilaterals and facing the camera in real time to simulate vegetation is explained, while the method of directly loading three-dimensional vegetation models has high rendering quality, but high calculation and storage overhead. According to different application scenarios and requirements, a suitable method can be selected for vegetation rendering, and LOD (Level of Detail) technology can also be used in combination to optimize the loading method of three-dimensional vegetation models.

[0023] The dynamic terrain editing is implemented based on the dynamic terrain editing algorithm, that is, by obtaining user operations as input parameters, the surface grid structure corresponding to the longitude and latitude coordinates in the ellipsoid coordinate system is modified accordingly, such as height adjustment, terrain shaping based on brush shapes, etc. When the terrain is modified, the image texture map and vegetation position are automatically recalculated.

[0024] S3, constructs multi-source heterogeneous data loading and rendering technology that is weakly coupled with the rendering pipeline, and realizes the integration of GIS rendering pipeline and game engine rendering pipeline, including vector graphics ground rendering, vector graphics model rendering, and BIM high-fidelity rendering. The specific rendering process is decomposed into data parsing and preprocessing module, rendering data construction module, and rendering pipeline module. The data parsing and preprocessing module converts multi-source heterogeneous data (including vector data, terrain & image data, oblique photography, point cloud data, BIM data, and conventional three-dimensional model data in FBX, OBJ and other formats) 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, buildings, city models, etc.); the rendering pipeline module selects the appropriate rendering pipeline to complete the rendering according to different rendering data formats, ensuring high efficiency and accuracy in the rendering process, thereby realizing data loading, rendering and coupling with the rendering pipeline. At the same time, the efficient coding compression technology of triangular meshes and the scheduling algorithm of CPU-GPU heterogeneous parallel computing are combined to improve the loading and rendering efficiency.

[0025] S4, loading the game scene includes deep fusion loading and coordinate compatible loading. The deep fusion loading converts the game engine terrain into a digital twin simulation terrain in the ellipsoidal coordinate system; the coordinate compatible loading is suitable for game scenes that can only be run in a plane coordinate system, and retains the original operation mode and rendering effect of the game scene in the digital twin simulation.

Claims

1. A method for constructing a digital twin simulation engine integrating a GIS engine and a game engine, characterized in that: The following steps are involved: S1, construct the coordinate fusion system of the ellipsoid coordinate system in the GIS engine and the plane coordinate system in the game engine; S2, build a terrain system including terrain data loading, image data loading, vegetation rendering, and dynamic terrain editing; S3, builds multi-source heterogeneous data loading and rendering technology that is weakly coupled with the rendering pipeline, and realizes the integration of GIS rendering pipeline and game engine rendering pipeline; S4, load the game scene.

2. According to claim 1, a method for constructing a digital twin simulation engine integrating a GIS engine and a game engine is characterized in that: Step S1 includes: S1.1, using Cartesian coordinate system, with the unit set to meters, to construct a three-dimensional space plane coordinate system; S1.2, construct an ellipsoid coordinate system based on the ellipsoid parameters of the WGS-84 coordinate system; S1.3, construct the coordinate conversion algorithm between the ellipsoid coordinate system and the plane coordinate system based on the ellipsoid parameters of the WGS-84 coordinate system.

3. According to claim 1, a method for constructing a digital twin simulation engine integrating a GIS engine and a game engine 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, and modifying the surface grid structure corresponding to the longitude and latitude coordinates in the ellipsoid coordinate system according to the elevation data to achieve a real terrain structure; the image data loading includes mapping the image data as a texture to the surface grid structure corresponding to the longitude and latitude coordinates in the ellipsoid coordinate system to achieve a real terrain appearance.

4. According to claim 3, a method for constructing a digital twin simulation engine integrating a GIS engine and a game engine is characterized in that: The image data loading also includes generating a normal map based on the image data to enhance the details of the terrain appearance.

5. The method for constructing a digital twin simulation engine integrating a GIS engine and a game engine according to claim 1, characterized in that: The vegetation rendering includes using billboarding technology, using 2D textures to construct quadrilaterals to simulate vegetation, and loading a three-dimensional vegetation model.

6. The method for constructing a digital twin simulation engine integrating a GIS engine and a game engine according to claim 1, characterized in that: The dynamic terrain editing includes obtaining user input parameters, modifying the surface grid structure corresponding to the longitude and latitude coordinates in the ellipsoid coordinate system, and calculating the image texture map and the vegetation position.

7. The method for constructing a digital twin simulation engine integrating a GIS engine and a game engine according to claim 1, characterized in that: Step S3 includes vector graphics ground rendering, vector graphics model rendering, and BIM high-fidelity rendering; the rendering process is decomposed into a data parsing and preprocessing module, a rendering data construction module, and a rendering pipeline module; the data parsing and preprocessing module converts multi-source heterogeneous 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; the rendering pipeline module is used to select a suitable rendering pipeline according to the rendering data format.

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

Images