Application And Research On Visualization Technology Of Digital River

Water is human indispensable and important resource, With 'Digital River' concept advanced, people want to build a digital river visualization system, which is not only necessary but also possible. Becouse that complicated characteristic of the fidelity and real time is a pair of the mutual restraint contradiction, this paper researches real-time rendering speeding technology, which works on the the changsha part of xiangjiang river environment. Because the contradiction of graphics simulation and real-time, The peper's major work is such as complex visual 3D modeling, LOD model simplification and visual interaction, and 3D visualization of water polution proliferation.Frist, We established digital levation model DEM (Digital Elevation Model) basin on the ArcGIS and through the direction of flow and convergence capacity to generate the river network, and then use a distance weighted interpolation mathod to get the basin river network.In order to resolve the three-dimensional visualization of realism in real-time, the paper proposed a Quadtree of multi-resolution hybrid algorithm. the method of ROAM algorithm (Real-time Optimal AdaptiveMeshes) and the block thinking, ROAM algorithm for each priority queues ,which ensure that the quality of the image and the real-time roaming requirements.Next, Point to the need of realistic simulation of the waterdhed, the paper proposed a dynamic model to generate a texture of the water and made an improved image Tiling texture mapping algorithm. the algorithm will Quadtree texture and response the geometry of the terrain well. thereby reducing the amount of computation texture coordinates, simplifies the process of generating texture greatly, depending on the algorithm within that region mapping, it saves storage space for the use of texture. At the same time, we use the texture and color-order model on water pollution to predict changes in water quality to provide a scientific basis.Finally,In addition, we design and development of a virtual watershed flythrough prototype system, which uses the real-time continuous algorithm above as the core. And proof the effectiveness of the aforementioned key technology.