A Seamless Visualizaton Model of the Global Terrain Based on the QTM

摘要

A seamless & adaptive visualization model of global DEM based on the QTM (Quaternary Triangular Mesh) is made to approximate to the Earth terrain in this paper. The approaches start with an Octahedron QTM partition based on the spherical surface. In order to improve the operation efficiency, the global DEM array points are organized as a hierarchy of Diamonds and the corresponding algorithms on indexing mechanism, coding scheme, and neighbor finding based on linear quadtree are given in details. Then, a dynamic operation method of the multi-resolution Diamond datasets in visualization is approached. Furthermore, an adaptive simplification rule of hierarchical triangles in Diamond data blocks is presented, in which an idea of the Binary Triangle Tree is introduced to form a continuous DEM mesh on the edges between different resolutions. In the end, the experiment and analysis are done with the GTOPO30 dada. The results is smoothly and receivable.