Study And Realization Of The 3D Pipe Network Geographical Information System

On the bases of the analysis of GIS and 3D GIS, the 3D pipe network is studied and the 3D Pipe Network Geographical Information System faced to the municipal engineering is constructed. A set of the 3D standard pipe unit templates is constructed, which contains ten types of pipe units of different sizes, for the modeling of the 3D pipe network. From the position of the intelligent design of the realistic construction, this thesis gives a new method of the pipe network geometrical modeling, with which the model constructed is the real description of the pipe network, and has good function of design and analysis. This thesis presents the algorithm of "three steps to choose the pipe unit, two steps to locate it" to construct the frame-ware model of the 3D pipe network, which can choose the proper type of the pipe unit, and orient it to the exact position. For the precision of the measure-tool, the measure-environment, and the measure level etc, deflection always exits so an algorithm is given to remove it. On the analysis of OpenGL operation theory, the visualization of the 3D model is realized, and, at the same time, the 3D rendered graph is given. The 3D model rendered has very fast velocity and good effect, which shows the spatial structure of the objects explicitly. The system gives the graphs in other modes, especially gives the algorithm of the 2D texture mapping of the 3D objects. The system realizes the 3D interactive operation, which is convenient for the visual operation and the informational management of the pipe network. And the system can give the properties of the objects and realize the query, the connection of objects and joint operation.