A 3D TOPOLOGICAL ER MODEL BASED ON SPACE PARTITIONING
Chen Jun ①② , Guo Wei ② (①National Geomatics Center, 1 Baisheng Village, Zizhuyuan, Beijing,China, 100044) (②LIESMARS,WTUSM,39 Luoyu Road, Wuhan, China,430070)
Three dimensional topological data model is one of the key issues in the development of 3D GIS. Pigot et. al.(1992) proposed to develop such a topological data model, but his work was limited mainly to the definition of k d spatial objects (0≤ k ≤3) with k cell complexes embeded in the open euclidean 3 manifold. Molenaar and the others extended the 2d topological data structures by adding some 3D relations between data types, such as is in,is on, vertical and relief. The purpose of this paper is to define a 3D topological data model by partitioning 3D spatial objects into k simplex. The Entity Relation (ER) diagrams between 3D objects (point, line, surface and solid) and k simplex were analyzed firstly. Then was proposed a 3D topological data model represented with ER diagram. The methodologies for data organization and space partitioning of 3D objects were further discussed.