Discussion On The Topic Of 3D Terrain Data Storage And Scheduling

It is the basic demand in the large-scale 3D terrain walkthrough system that the large-scale 3D terrain can be displayed dynamically with high frame rates, according to users' interactive instructions. It is impossible that all the DEM and texture data of the scene are loaded into memory to be rendered, because of the complexity. So one of the key technologies of the large-scale walkthrough system is how the massive data of DEM and texture should be organized and stored, and which reasonable and effective dynamical schedule strategy of scene data should be used.Two aspects are concerned, when rendering 3D terrain: one way is that it is realized in the stage of data being loaded from storage to memory, by the technology of effective organization of data, LOD previously processed, dynamically loading data to memory through visibility culling and effective management in memory; the other is that in the stage of data being rendered in memory, the rendering triangles' number is reduced before scene being rendered, by the ways of reasonable simplification of the data in memory using the technology of polygon simplification and multi-resolution model . At present, optimizing algorithms are concerned with the above two aspects. The first aspect is mainly discussed in my essay.Rendering technology of large-scale scene at present, are introduced in my essay. Typical storage ways are summarized and analyzed, concerned with large-scale massive scene data. Combined to the project of Qingjiang River walkthrough system, a reasonable division method is described. Based on the data structure and the idea of dynamical pre-schedule, a feasible dynamical pre-schedule algorithm is designed, with the multi-thread technology, which enhances the frame rate and realizes the display smoothness and continuity of the large-scale scene walkthrough system, compared to walkthrough system, which does not divide the scene and use the pre-schedule strategy.