Research on 3D Model Construction Method Based on Geographic Information System

How to establish large-scale 3D GIS efficiently and accurately has become a key issue restricting the development of urban 3D GIS. A large-scale 3D modeling algorithm for abstract objects such as abstract points, lines and surfaces is studied based on the analysis of the principle of terrain modeling in 3D GIS. The software can create various types of 3D models, display and browse, query spatial properties, interoperate, measure and analyze them. The software can not only conduct 3D modeling under the ground, but also overcome the problems that the existing 3D modeling methods can only display but cannot query, measure and edit. The model has the advantages of simple operation, fast operation and automation. It is of great significance in the modeling of terrain, such as ground, river, road, green space, regular building, underground pipeline, etc. Taking the rapid modeling technique described above as an example, the effectiveness of the proposed algorithm is proved.