A Research On The Key Rendering Techniques Of Complex Scene

In recent years, the techniques and applications of complex scene have been given extensive attention. Especially the dynamic Rendering technique of large scale 3D-Scene has been a research hotspot of virtual reality at present. This thesis, which regarding the Ocean Monitoring Integrated Information System as the subject background, directing against the domestic and international current research situation, has discussed three-dimensional maritime affairs GIS several key technologies. There are three following respects mainly:First, a dynamic and consistency keeping simplification method based on the polygon vertex normal is presented in the thesis; the method can cut down data redundancy in large extent with certain vision impression contained.Second, Accorded with the actual projection DEM, a fast drawing method of the complicated scene is proposed. The techniques related terrain LOD is systematically studied based on the quadtree data structure. Combining the data block attemperation idea, we solved the data integrating and preculling problem, presented the boundary constraining solution, and calculated the collision detection for rambling. These techniques greatly scissor the data scale for computer disposal, and make rendering scene more virtually and rapidly than before.Third, a new advanced programme language named Cg is used, which designed for programmable GPU. Certain operations of CPU can be transferred to GPU by Cg, which offer the possibility of more rapidly and finely rendering.Fourth, a 3D Marine GIS is designed and implemented based on the above content, which well validates the rapid rendering techniques effect.