3D GIS Integrated Model Simulation Algorithm Based on Block Model

In order to organize and manage 3D GIS spatial data effectively, and represent 3D spatial entity integrally, a hybrid data structure model called BOT model (block octree tetrahedron model) is presented on basis of geological block model, which combines octree and tetrahedral network (TEN) structures. Using BOT generation algorithm, the block model is redivided with octree as general shape description and TEN as partial precise description, in which different gradation of grey are used to stand for different attributes of unit blocks. To reduce the memory space a linear BOT coding technology is proposed as well. The results of simulation experiments made with empirical data demonstrate that the BOT model holds merits of both octree and TEN and can represent 3D objects more effectively and precisely. Moreover, the algorithm simplifies modeling process and to a certain extent, reduces computing complexity for visualization.