Study On Three-dimensional Visualization And Spatial Data Management Method

In this paper, study on organization,storage and visualization of the massive terrain dataset.By building mass DEM terrain multi resolution model to organization the data,using data engine to store and dispatch the large-scale terrain data. Design the visualization system of the South Mountains and North Mountains in LanZhou city on these rationale.The system haves the functions of spatial information inquiry, spatial analysis, the three-dimensional scene flight simulation, calculated from the quantity, different viewpoint scene browsing, data dynamic demonstration and so on.Interpolation and simplifying methods of Digital Elevation Data is introducted here. These paper dose a research on the simplifying method of RSG model and TIN model. In view of the importance and difficulty of building a TIN terrain model, we discuss it specially in a single chapter , explaining in detail data structures and key algorithms.Design a Pyramid Model for multi-resolution virtual terrain environment, and then implement this model by way of LOD. Related to the model designing, is how to divide the mass terrain data into different levels and blocks in terms of latitude and longitude. As for the structure of each terrain block, we introduce TIN model into the Pyramid Model, and magnifying and to speed up texture creation during real-time rendering, we adopt Mipmap texture method, which includes how to create Mipmap textures foe each terrain block, how to compress these textures, and how to organize them in the Pyramid Model. Introduce the concept of Rendering Engine into the system, and explain how close it is to the above Engine, Data Engine.Design and implement a virtual terrain environment system of the South Mountains and North Mountains in LanZhou city. This system, developed by Visual C++, OpenGL, COM/ATL, etc, is the result of above researches, and needs to be improved in the future.