A New Integrated Data Structure for 3D GIS

In order to organize and manage 3D GIS spatial data effectively, and represent 3D spatial entity integrally, a new simulation modeling algorithm is put forward, which combines data structures of constrained TIN and CSG. In this algorithm, TIN model is used to represent terrain and CSG model is used to represent buildings. The two simulation models are integrated by extracting ground contour lines of buildings as constrained conditions when carrying out triangulating terrains. And the visualization for all parts of the integrated model can be processed synchronously. The results of simulation experiments made with empirical data demonstrate that the algorithm simplifies modeling process and to a certain extent, reduces computing complexity for visualization