Research On3D Geospatial Environment Modeling And Rendering

Geospatial Environment Visualization can realize graphic image communication between people and dataand among people, which can make people perceive information hidden in data sufficiently, supplies apowerful tool to discover and understand geospatial intelligence, and realize inference and early warningthrough changing dependencies by interactive methods. This paper researches on theory and algorithm of3Dgeospatial environment visualization based on high-resolution satellite images and focuses on effectiveorganization and management of massive terrain data, LOD algorithm of large area terrain and modeling andvisualization simulation of virtual battlefield environment. In the end, a visualization prototype system ofvirtual geographic space environment is achieved using high-resolution remote sensing images and DEM ofborder area. The main contents in this thesis can be summarized as follows:1. Organization and management of3D terrain visualization data are researched in this paper. Global imagesand DEM data is delaminated and blocked on condition of some constraints, and pyramid hierarchy model ofglobal high-resolution terrain images is constructed in this paper which also introduces the process of datatiling and scheduling.2. Based on the need of real-time rendering of extensive vector data, this paper focus on the organizationand management of multi-resolution vector data on basis of quadtree structure. Pyramid hierarchy model ofspace scene based on loose quadtree structure is constructed. Unified organization and scheduling of terrain,images, vector data and solid models are realized in this paper.3. This paper analyses problems and solution methods of extensive terrain real-time rendering andresearches on some key technology such as grid simplification standard, hierarchy selection and crackselimination of LOD algorithm of large scale terrain. It realizes real-time rendering of large scale terrain andefficient and precise rendering of vector data by using of stencil shadow volume algorithm.4. Key technology process of modeling and visualization simulation of virtual geospatial environment isdiscussed and some algorithms such as particle system, multi-layer sky model, dynamic cloud model and seawave equation are researched. By using of the algorithms above, this paper realizes simulation andvisualization of environment elements including sky, dynamic cloud, rain, snow, and dynamic water.5. Combining theories research result above and using3D graphic programming interface of OpenGL, thispaper develops a3D virtual geospatial visualization prototype system and realizes dynamic3D visualization oflarge scale terrain data of western border area. Some experiment results are given at last.