Quad-Tree 3D Modeling Technology Oriented to WMS-Based Raster Grid Data

For WMS-based projection plane data this paper puts forward a comprehensive construct method and optimization technology of global 3D modeling by Quad-Tree Model. In that model, tile region is set by its layer index and grid index according WMS data organization characteristic. Followed, based on statistical methods, by setting constant value to coordinate layers index we implement layers optimal matching and keep layers of images tiles, DEM blocks and model nodes consistent with each other. Even more important, for the particularity of WMS-based projection plane data, we analyze tiles distribution characteristics in zonal direction, and find out a technical means to optimize tile mesh modeling based on area change curve segmentation dividing. At last, according to experiment and experience, we propose out dynamic segmentation strategy to optimize mesh size by fixed segments proportion array list and work out its implementation in detail. In order to verify the validity of this approach, this paper also gives the method of calculating the theoretical efficiency lifting and the assessed result value. In fact, in our specific application, efficiency improvements have been far beyond the 5 times since it integrates other optimization methods.