3d Gis Spatial Data Model And Visualization Techniques

In this paper, we focus our research on spatial data model and visualization techniques on the basis of spatial database in 3D GIS.We analyze in detail the difficulties in integration of field-based model and object-based model, and propose an object-oriented 3D GIS integrated model. We also discuss the architecture of the integrated model.Until now, there is no general representation for 3D topological structure, especially topological relationships between 3D solid objects. Based on a certain space, we define several basic topological relationships. Thus other complex topological relationships can be deduced efficiently independent of geometry embedding. Through formal description of binary topological relations, we propose an optimal method to compute 3D topological relationship.Based on V-Reactive index tree and perspective query, we propose a mechanism of integrating LOD and generalization at multi-scale. According to characteristics of 3D visualization, we analyze some methods for optimal performance and discuss dynamic buffer management technique on 3D object. In this paper, we propose an architecture of 3D Web-GIS on the basis of spatial database and VRML.We design and implement a 3D GIS experimental system. The system implements some basic functions of 3D GIS and many techniques proposed by the paper. Moreover, through creation and conversion of CAD data, a 3D school experiment GIS is implemented.