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Since the 20th century 90’s, with the rapid development of computer graphics technology, researches in the fields of visualization, 3D-GIS and so on rapid progress both at home and abroad. Cross-disciplinary research based on three-dimensional (3D) geometric modeling, virtual reality, 3D geographical modeling and so on has become the research hot spots. Many scholars, research institutions and software companies are actively exploring the theoretical research and software development of 3D modeling and visualization.Firstly, the paper sum up background knowledge of visualization, 3D model, and sum up correlative software’s development research at home and abroad, and make out the content and significance of the paper’s research.The paper studies detail on the basic theory, digital terrain modeling, and 3D visualization of model. In the part of basic theory, the paper sums up the geometry transformation and OpenGL visualization technology. Then, the paper research on conforming Delaunay triangulation, including the incremental insertion algorithm, the boundary segmentation algorithm, natural neighbor interpolation, the quality control and size control of triangulation, expatiate the algorithm process, the definition of data structure and compile program apply the corresponding function.Then, the paper studies on the visualization of 3D models. Carrying out 3D visualization of terrain based on the triangulation algorithm, including effect of the wire-frame map, the gradient colors, texture mapping, etc. And the paper researches on the contour tracking, tagging and visualization. Other, the paper achieve 3D visualization of the landscape, including buildings, sky, trees and street lamps; achieve operation of roaming and inquiries. Building models come from of the external 3D model file such as 3DS and DXF files. The paper analysis the files and given data acquisition process.Finally, the paper shows the system design framework and function modules. The system is development with OpenGL and the VS2005, and is designed by modular to do a good expansion and transplantation.
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