Real-time Visualization Technology Research And Implementation To 3D Riverbed Terrain Based On OpenGL

The visualization of three-dimensional terrain can be used to reveal the information and synthetical character of 3D terrain directly and really. It is widely used in many fields. And it has broad practical foreground. With the fast development of computer technology and broad application of 3D GIS, 3D terrain visualization has become the foreland and focus subject in harbor and waterway engineering to analyze riverbed evolvement and sediment transportation. It is also an important method to reveal 3D information of the riverbed terrain throughly and quickly.Based on lots of advanced results of computer graphics, modern mathematics, computer science, GIS and topography, etc. this thesis discussed the related theory, techniques and arithmetic of three-dimensional riverbed terrain visualization implementation based on OpenGL, detailedly including the basic theory of three-dimensional visualization and three-dimensional terrain visualization, three-dimensional geometry sculpting techniques,the means of curved surface fitting of discrete data, the principle and the related techniques of OpenGL, the main style of DEM, several main difference methods of discrete data gridding, the improved arithmetic of discrete data gridding, three-dimensional terrain modeling techniques, the implementation theory of the third dimension graphics, the query techniques of three-dimensional coordinates and the interaction of person and computer.At last, based on the researched result of the above theory, based on windows2000 system and Visual C++ 6.0, the three-dimensional visualization real time browse system using OpenGL has been established. The system can receive and pretreat the discrete data of TXT format, realize different pattern three-dimensional visualization of line, different color and texture, etc. and has the functions of real time dynamical browse, three-dimensional coordinates query, grid data and three-dimensional figure export etc.It has too the functions of three-dimensiona contrastive figure drawing and contrastive data export of alterant riverbed terrain.This investigation has important theoretic and practical meaning. In theory, the improved arithmetic of discrete gridding , three-dimensional terrain modeling techniques , three-dimensional coordinates query technology about three-dimensional terrain visualization are investigated. In practice, a digital, visible and intelligentized three-dimensional visualization dynamical browse system of riverbed terrain in the water field is builded, providing a scientific ,valid, easy and direct way for riverbed evolvement analysis.