Research And Implementation Of Large-scale 3D Visualization System And Key Technologies

Along with the rapid development of computer graphics,three-dimensional visualization,as an important branch,has been more and more widely used in the fields of virtual scene display,interactive operation system(such as smart city,IOT,virtual battlefield),Geographic Information System(GIS)and Build-ing Information Modeling(BIM).With the continuous development of WebGL technology,the demand for web-based large-scale 3D visualization system is increasing.Based on the research of large-scale 3D visualization system and its key technologies,this paper proposes a 3D visualization solution based on HLOD,and proposes a slicing algorithm to divide large-scale scene models,while managing the chunk by using a tree structure.First of all,this paper through the in-depth study of the main concepts of HLOD,combined with the actual needs of the project,and proposes a large-scale 3D scene visualization solution based on HLOD.Through simplified screen space error(SSE)expressions,it is determined that viewpoint param-eters and object geometric errors are the main factors affecting SSE.Then a dynamic rendering selection algorithm is proposed to dynamically select chunks for rendering.Based on this algorithm,the rendering selection algorithm with prefetch optimization is also proposed,which further improves the operating ef-ficiency and user experience.The real-data experiment proves the effectiveness of the proposed solution.Secondly,large-scale 3D scene models are often bulky and complex in structure,and using a single model file cannot meet efficiency and performance requirements.This topic proposes a large-scale scene model slicing algorithm.The large-scale scene model can be divided into smaller chunk files,and the octree structure is adopted for management and index.Then the chunk data format is designed,including chunk index tree JSON structure and binary chunk file format.The experiments show that the chunk results in this paper perform better at runtime.Finally,a large-scale 3D visualization system is designed and implemented in this paper,and various functions and system performance tests have been completed.The work achievements and actual system of this paper have been effectively verified on enterprise projects and the campus competition project.