Three-dimensional Realization Of The Digital City Buildings

Digital city is the important node which constitutes digital earth and will take a great role in building digital earth. With the level of computer quickly developing , it is the trend toward 3D digital city in building digital city. Firstly this paper ananlyzed the way and problem of digital city in 3D visualization .then generalizing the development in 3D CIS .especially in 3d spatial data model. Based on the existing 3D data model, digital city is composed of piont, wire, surface> soild , we can use 3D vector data model in building 3D city model. On the other hand the paper emphasizes 3D reconstruction and 3D interactive of city building model. Finally, the paper discussed the integration of 3D city model and Virtual Reality in theory,it may be realized to manage and analyze 3D information by internet.Based on the theory of 3D data model,the paper explored a desktop 3D city building model, developed with Delphi and OpenGL. Many fuctions are implemented in this system, such as 3D reconstruction, 3D edit operation, 3D data management, special analysis and so on. The city model can be served as city programming and sight analysising.