WebGIS-based Information Service Of Underground Pipeline And Pipeline's Surface Reconstruction

Along with the development of the city, the underground pipeline is more and more complicated. Under this kind of situation, it's inevitable that the underground pipeline would be managed by means of GIS. However, the pipeline belongs to different department, and the information sharing is not expedite, which causes blindfold operation by the department of construction design and the accident of the pipeline. Therefore, it's necessary that a mechanism and platform of WebGIS-based and integrative pipeline information service should be established. At the same time, in consideration of the vertical and horizontal interleaving of underground pipeline, the spatial relation of the pipeline can hardly be expressed by the 2D pipeline information system. In order to show the relation better, the 3D visualization of the pipeline which combines the technology of surface reconstruction and Web3D owns the important research value. In this paper, the key technology of WebGIS-based pipeline information service, modeling and rendering of surface reconstruction is worked over. These technologies are applied in the system of underground pipeline information service of Fuzhou University. The main contents and the innovation points are as follows: 1) By the research of pipeline information service, a mode of WebGIS-based pipeline information service is brought forward and a system of information service combined 2D and 3D is built. 2) The pattern of WebGIS-realization, system structure and the data model of underground pipeline information system are researched. Base on the research, the WebGIS-based three-hierarchy form and the pattern of mixed framework for the underground pipeline information service are put forward. 3) Because the information service requires strong interactive and a small quantity of data on Web, after contrasting surface rendering with direct volume rendering, a conclusion that surface rendering of slice-based is fitter for the surface reconstruction is draw. During the surface modeling of pipeline, a means to get the shape points is introduced. In this means, shape points were calculated by surface outline equation which was got from quadratic surface. By this means, the pipeline and its curve part can be modeled quickly and the rendering of LOD can be controlled agile. Then these shape points were patched by the way of adjoining contour outline synchronous progress. Finally, the models are rendered by Java3D, simple illumination model is adopted and surface vector is calculated. 4) The underground pipeline information service system of Fuzhou University is built up. Besides the conventional function of WebGIS system, aiming at the characteristic of pipeline, the service of accident disposal and pipeline's 3D visualization is discussed in this paper. In addition, under Web3D pattern, the service of picking and attribute querying which referred little in interrelated paper is carried out.