Design And Implementation Of Chengshiguanwang Three-dimensional Model

Urban underground pipeline network is composed of water-supply,drain,gas, heating,electrical,telecommunication,and industry pipelines,which are interlaced underground.They are the important component elements of city's infrastructure,and are considered as the lifeline of the city.As the development of modern construction and management,many cities have already researched and built the urban pipe geometry information system(UPGIS).However,the visualization of the existing UPGIS is mostly two-dimensional display.In order to reflect the real spatial relationship between pipelines clearly,people developed the 3D three-dimensional (3D) visualization,which will provide users the 3D modeling and 3D display service for each type of pipeline network.Building the 3D model for the pipe network is one of the basic tasks of the pipeline network 3D visualization.One the other hand,it is also the foundation to do the 3D spatial analysis for the huge and complicated urban pipe network system.It can provide technical methods for scientific decision,economic dispatch,optimizing configuration,and so on.So it is highly necessary to build the 3D model for the pipeline network.This paper mainly researched the construction of the 3D model for the urban pipeline network.It includes the foundation of the 3D model of the pipeline network system --- pipeline network data model,and the 3D topological structure based on this data model.On the other hand,during the construction period of 3D pipeline network model,in order to increase the efficiency of 3D modeling,we proposed the pipe unit library to provide the 3D modeling element quickly,so that we can increase the modeling efficiency.The 3D pipe unit library allows users to view,edit the 3D pipe unit models visually.It is a foundational work for constructing the 3D pipeline network model,which will release the developers from pipe unit modeling,and pay more attention to the function design for the pipeline information system.In order to display the pipeline network more vividly,this paper also researched related technologies for pipeline visualization,including the 3D texture mapping technology and the mutual technologies such as viewpoint switch and mouse mutual operation to increase the realistic.In the end,to illustrate the usage of the above researching work,we share our experience in implementing the prototype system for 3D pipeline network visualization.This system included both the 2D and 3D visualization.In the 3D visualization,it used the 3D pipeline network data model,3D topology structure,pipe position in the 3D space,error rectification and the 3D pipe unit library.The results reach up to our design goals.