An approach to terrain geometry modeling and visualization in virtual city

The technique of terrain geometry modeling is one of the most important research fields in the simulation of virtual terrain scene and virtual city. Concerned problems include 3D model, 3D data management, 3DGIS, visualization, and so on. This work firstly discusses the advantages and disadvantages of the existing methods for geometry modeling. Based on the requirements of 3D models, general 3D data structure and simplified spatial model, a new way of constructing terrain geometry models for implementing minor data storage and fast visualization is proposed. The integrated algorithm of terrain mode and 3D object is also developed in order to keep the consistency of topological relationship among geometric models. Thus the virtual city structure (terrain + 3D objects) is easily developed to store and manage the geometric and attribute data of digital city, which is the foundation of data management, visualization and spatial analysis.