An Oracle8i-based approach is proposed to manage the integrated databases oflarge CyberCity. This approach consists of three schemes: ① a special R+-tree index is designed toaccelerate spatial retrieving, in which the bounding boxes of local regions have no intersection andall leaf nodes of the R+-tree (geometry records ) have no repetition; ② different data compressionalgorithms are adopted to compress the digital elevation models, 3D vector models and images, suchas LZ77 lossless compression algorithm for compression of vector data and JPEG compressionalgorithms for texture images; ③ in order to communicate with Oracle8i database, a CyberCity GIS.spatial database engine (SDE) is designed. On the basis of this SDE prototype a case study is done.
Several different strategies of 3D modeling are a do pted for different kinds of manmade objects. Firstly, for those manmade objects with regular structure, if 2D information is available and elevation information can be obtained conveniently, then 3D modeling of them can be executed directly . Secondly, for those manmade objects with complicated structure comparatively a nd related stereo images pair can be acquired, in the light of topology-based 3 D model we finish 3D modeling of them by integrating automatic and semi-automat ic object extraction. Thirdly, for the most complicated objects whose geometrica l information cannot be got from stereo images pair completely, we turn to topol ogical 3D model based on CAD.
