A New Hybrid Data Structure for 3D GIS

In order to represent 3D GIS spatial entity effectively, a hybrid data structure model called BOT model (block octree tetrahedron model) is presented on the basis of geological block model, which combines octree and tetrahedral network (TEN) structures. With BOT generation algorithm, the block model is redivided with octree as general shape description and TEN as partial precise description, in which different gradations 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. Finally, a 3D simulation system was developed to evaluate the performance of the approach proposed. 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.