Researching And Practicing Of City Scene Modeling Based On Remote Sensing Data

The 3DCM (three dimension city modeling) is hotspot of digital photogrammetry, GIS and other correlation study. On the basis of reviewing the current research status of 3DCM, this paper chooses the 3DCM which is based on remote sensing images as the main topic, and carries through comprehensive and systemic study from theory to practice. The main works are as follows:1.A building modeling method, which is called CSG block analyzed method for ground photographs, is presented in this paper. It uses CSG as the primary representation and describes each building by a combination of one or more basic CSG primitives, then calculates the camera parameter and calculates the size and position of CSG block. The method combines the man intelligence and the efficient of computer, so is more reliable and practicable.2.A semiautomatic approach for the extraction of buildings from large-scale areophoto, which is called the monoscopic and stereoscopic integrating analysis ,is realized in this paper. The approach consists of three stages: preprocessing, monoscopic processing, and stereoscopic processing to solve the problem of regulation buildings extraction from remote sensing images.3.The new TIN construction algorithm, which is based on self-adapt clump organization idea, is provided in this paper. The algorithm takes advantages of the traditional prevalent Delaunay triangulation generation algorithms-divide_conquer and incremental insertion, and is more correct and efficient in the view of time and space.4.On the base of simplicial and CSG hybrid data model, an virtual city scene modeling project is presented and realized. The project consists of the generation city solid model based on hybrid data model, represent of r~ation and feature information, VRML node export etc. The method, which can use 2D GIS data and 3D attribute data to construct 3D model of city directly, and can promulgate 3D city scene through INTERNET.5.The data structure and edit algorithm of constrained Delaunay irregular triangular network are provided and realized. The building and terrain joint method and main step are presented on two different ways.6.Detailed illuminated the construction and basic operation of belt feature object jointing with terrain. The object is expressed by object format and can realized solely control to meet expression and feature management.7.Realized the 3D terrain real-time rendering based on approximate tree organization. Detail discussed the structure of approximate tree, texture LOD represent, terrain rendering process and the crack elimination method between the tree nodes8.Developing a system of CityView on Window NT, which uses the oriented object program idea to analyze, design and software realize, is more advanced and practicable.