Ordos Basin, 3d Terrain Visualization And Its Application

The ordos basin has big area and complex physiognomy, 3D visualize it is a defiant task. Presently, due to limited hardware capacity, for the large scope terrain, the real-time modeling and visualization is still a big problem. So using modeling way to solve large data real-time display is only way,Thereinto,multi-resolution display is a good way for creating and real-time rendering virtual terrain scene.In this dissertation, the characteristic of 3D visualization has introduced at first, pointed out that display speed is the key problem of the 3D visualization. Second, it summarized the advantage and disadvantage of the 3D visualization technique and muti-resolution display model which based on TIN and GRID, also introduced texture mapping principle, many mapping method and texture create way, especially Mipmap technique. Based on survey of existing methods, some new algorithms and improvements are presented in detail here. For rendering real and quick speed 3D terrain, dissertation emphasized on how to build LOD of erdos basin which based on quadtree. At last, the dissertation combine 973 science and technology item, applied DEM and many information complex, approved that 3D visualization of terrain is useful in mineral resources explore.When discussed erdos basin real-time display by LOD, the dissertation compared many methods of visual threshold cut, error calculate and crack repair, selected perfect method in order to reduce data. Of course, a little date must be reduced smooth, so we applied Mipmap texture technique to approve it.Experimental results show that quadtree method be satisfied the ordos basin display by 3D, Error calculate method which considered terrain and view distance is reasonable. Additional,quadtree method can clear up crack and achieve muti-resolution at random. In application, people can reduce triangle count by adjust error value. If helped by hi-resolution texture, it can realize 3D display of ordos basin but not reduce the quality of terrain scene even if in PC environment.