The Organization And Structure Design Of Vision Information In 3D GIS

How to realize the information visible output in the three-dimensional geographic information system is the important point in this domain research continuously. Many applications domains, like virtual reality, military exercises, network game and so on, all request the three-dimensional scene to dynamic demonstration accordance with the user demand. Along with the development and the innovation of the computer science, the computer graphics as well as the modern data theory, the question is also attracting more and more researchers. But the terrain and the surface features are extremely complex natural view, which involve the spatial geometry data, the texture data and so on. It goes without saying that the data is magnanimous. How organizes these data, makes it advantageous for management, query and visualization output, is the key of the three-dimensional geographic information system at the present research.To resolve the problems of massive data in 3D GIS is focused on how to reduce visible output data as well as how to simplify the massive data. In regard to reducing output data visualization, the thesis leads into establishment scene index mechanism, which helps to determine visible region and simplification degree according to height and location of view. For spatial position data, it mainly adopts the combination of methods with R-tree and LOD principle, which considerable reduces 3D point numbers and triangle numbers. Meanwhile, it realizes the original model and simplified model equal in value. For object texture, it mainly adopts the methods of reducing the redundant texture data so as to reduce the image data. According as reducing of the data quantity, it lets user feel that along with the viewpoint changing, the scene simplification degree is also changed, thus obtain the effect which experiences personally. The organizing management method of the three-dimensional geographic information system (GIS) in this thesis is based on the acquisition tool and the treatment processes of the data which in the system. It includes path information adjustment, the three-dimensional model establishment and simplification, the texture organization and attachment mode as well as the realization of visual effect. According to characteristic and request of the material process, it discusses and introduces the corresponding visual information organization pattern, and also provides data structure of the three-dimensional GIS visual information as well as the corresponding database design.