3D spatial modeling for urban surface and subsurface seamless integration

3D urban geological modeling is an important research issue with the studying of the digital city in China. In view of the deficiencies of present modeling methods, an integrated model based on GTP data model is presented. It applies ground engineering, terrain, geological body, underground engineering model and be comprised of the following geometric primitives, Node, Edge, Arc, Triangle, GTP. Triangle is the most basal geometric primitive in this model. The seamless integrated model of urban surface and subsurface can be created based on above data model. The principle of the seamless integration modeling of aground and underground objects, the implement method for the seamless integration modeling is introduced. A real-3D geosciences modeling system, GeoMo3D, developed with VC++, OpenGL and SQL sever, an actual 3D geological model of an exploring district, is shown as a case.