Massive Terrain Real-time Renderin Technology Research Based On The Quad-Tree

The terrain visualization concept is gradually formed in the1960s with theemergence of geographic information systems and it is a subject that study displayand simulation DTM digital terrain model. Its application involving GIS, virtualreality, the flight through the terrain.This paper is mainly study the display and simplify the multi-resolution terrain、aalgorithm that is about the exchange from the external to internal storage and atechnology about the texture mapping. Some mainly results is following:(1) Propose a multi-resolution node evaluation system that is based quad-tree.themethod of the system is according to the distance between the viewpoint and objectand the roughness surface of the object to select to draw the different resolutions node.And then propose some optimization algorithm, such as crack eliminate, view frustumculling, back removed. It is achieve a large-scale terrain fast roaming that is showedby experiments..(2) Research the terrain data organization and scheduling algorithm for massiveterrain. Propose a dynamic scheduling strategy based on terrain data block and use theprefetch method to realize the data exchange scheduling between the out-memory andin-memory. Finally, through the experiments verify the validity and feasibility of thealgorithm.(3) Introduced the terrain texture data structure and commonly used method fortexture mapping. Propose a multi-resolution texture mapping algorithm based onmipmap. And on this basis propose some key optimization technology such asselection the quad-tree of the texture node、multi-resolution texture real-time load、thetexture border processing.