3D Undersea Terrain Visualization Based On Computer Graphic Processing Unit

With the development of information technology, terrain visualization technology hasbeen used in various fields. Seafloor terrain visualization is discussed as the hot issues oftoday. Due to the complicated seafloor topography, the seafloor situation is a mysteriousplace for people in the current stage. So the bottom topography is the focus of research inrecent years.This paper based on VC++6.0as a platform, use the quadtree viewpoints related LODtechnology interpolation to construct grid, use OpenGL3D programming interface for thetransformation of coordinates and cutting out the right viewport size, then Cg senior shadinglanguage is applied into the3D graphics program for terrain rendering in order to call thecomputer graphics processor to complete graphic processing. Its powerful parallel processingability meets the purpose to speed up the computation speed.Paper used real terrain data to model DEM. DEM file operations are introduced in detail,including data structure definition, generation and load. Rendering terrain method usingquadtree LOD algorithms for terrain modeling, constructing process of quadtree datastructure and eliminating the cracks are described so as to realize the terrain according to thedifferent viewpoints of distance using different level of detail.Rendering is performed on the graphics processor (GPU), using the Cg advancedshading language to add light, texture rendering and environmental mapping. The result ofusing the GPU and CPU parallel processing is compared with that of only using theperformance of the CPU for processing, which demonstrates the GPU powerful advantages interms of graphics rendering.Finally the terrain visualization system is realized to display the underwater real-timerealistic terrain by human-computer interaction, and the grids can be changed by renderingmode switching and seabed terrain roaming.