Research On Massive Special Data Visualization In 3D GIS

3D GIS is a 2D GIS in the expansion of 3D space, to express their reality and the representation of 3D reality of the advantages of being focused upon. And organizations to manage massive spatial data and socio-economic areas such as management and research needs of its growing strongly. However, the 3D GIS theory and technology is not mature enough, the scope and extent of application are limited, compared with the general 3D design, 3D GIS of the huge amounts of data, real-time visualization, spatial analysis and other features, reflect the 3D GIS in a number of basic the problem is far from being well resolved. Massive spatial data visualization is the study of 3D GIS, one of the hot spots.In order to build a massive research environment visualization, spatial data, this paper is based on mass, are discussed in detail and based on the 3D space based on the model surface and the associated vector, raster data structure. Massive spatial data in order to enhance the efficiency of visualization as the goal, to discuss building a spatial index Octree principles, methods and related inquiries, insertion and deletion of spatial objects, such as the index operation. Visualization in 3D mapping is proposed in this paper based on the 3D octree approach blanking. The method is octree spatial index on the basis of the analysis of spatial objects in the octree level position, to determine whether it should be hidden. Finally, the use VC + + 6.0 develop the language, combined with OpenGL graphics API, the realization of a hidden three-dimensional scene to deal with.In this paper, a lot of work to do to build a processing massive spatial data visualization prototype provides a research model visualization issues, algorithms and evaluation of environmental efficiency. Practice has proved that the octree index can take full advantage of storage space, and the orderly structure of the hidden objects to deal with effectively. Octree-based deal with the blanking, blanking algorithm reduces the calculation of the intersection of computing, improving the efficiency of the blanking algorithm.