Research On 3D Scene Simulation Optimization Theory And Arithmetic

Massive data scene real-time simulation is not only the one of main researches for digital earth application techniques, but also the important problem to be resolved for geographical information system developing towards the 3D analysis phase. With the quantity of 3D scene data increasing and popularization of graphics processing unit specially designed for graph rendering, if not obviously decreasing the graph quantity and complex of 3D scene, the research that some effective data processing and graph rendering methods can be applied on general computers to speed up rendering and solve the conflict among the speed, quality and complex of massive data scene is becoming an important direction.Supported by National Key Technologies R&D Program Olympic Games Dedicated Projects "Research of dynamic monitor for Beijing Olympic Green Environment" and the Chinese Academy of Sciences Knowledge Innovation Program Science and Technology for Olympic item - research of high-resolution remote sensing monitoring and 3D simulation for the Beijing Olympic area, the related theory and methods are discussed and applied in this dissertation including the automatic simplification for models in massive data 3D scene, the viewpoint relevant selective real-time refinement and optimally processing assisted by GPU. The design and development for internet release and web browsing of virtual Beijing Olympic Park system are accomplished. The functions such as the display of 3D scene, operating models and attribute information query are realized at last.The main works and innovations of this dissertation are as follows:a) The preprocessing module of automatic simplification for 3D models is accomplished. Based on the primary quadric error metric arithmetic, combined with boundary constrained condition and normal restriction, the primary arithmetic is modified and the application scope is extended. The new arithmetic can preserve the appearance of original model and decrease the quantity of triangles of models to build the level of detail for 3D scene, and keep down the file size to an appropriate one for internet release of 3D scene. From the point of 3D scene imaging, comparing to the primary arithmetic, the result obtained from the improved arithmetic can preserve higher similarity with original models and has better display quality.b) The viewpoint relevant selective real-time refinement arithmetic is realized. The progressive mesh method is applied to effectively storage the mesh information and support the automatic building of multi LOD and smooth transition and the quick visualization effect can be obtained. In order to speed up the graph rendering, the viewpoint relevant selective mesh is implemented, which can obviously enhance the detail of target area and reduce the detail of some areas for less or no contribution to the ultimate imaging and effectively lessen the rendering burden of graph pipeline. The boundary piece concept is used to provide the theory base for the progressive mesh selective refinement scheme. All possible selective mesh sets are listed and visualized, which result in not introducing additional vertex split and edge collapse...