关键词: 可视化;二阶10节点四面体;等值面抽取;关系矩阵;压缩索引结构

Abstract: In order to solve the problem of isosurface topologies and the cost of triangular patches computing, storage and transmission during the visualization process in second-order 10-node tetrahedrons, the isosurface extraction method based on compressed index is proposed. To reflect the real topology of the isosurface and overcome the ambiguity, the method analyzes and simplifies the parameter interpolation function of second-order 10-node tetrahedron, proposes the matrixes of relationships between vertex, surface and cube, calculates accurate contour points in edge, extracts surface and mesh key points which can performance the geometric topological characteristics of isosurface in mesh grids, designs a key point matching rule; based on the logical relationship among the three types of interpolation critical point, it develops the isosurface triangulation and optimization rules which have accurate and unique topologies，and the split-style compress index structure of triangle to triangulation, image optimization and drawing. The experiments show that the method can describe the isosurface accurately and define an unique geometry topology within second-order tetrahedral mesh grid, the calculation and splitting optimization method based compressed index structure is simple and effective, it has the adaptability to different accuracy requirements, and can reduce the cost of computation, drawing and transmission dramatically.

Key words: visualization;second-order 10-node tetrahedron;isosurface extraction;ralationship matrix;compressed index structure