适应于体绘制技术的三维有限元网格剖分

PARTITIONING 3D FINITE ELEMENT MESHES FOR VOLUME RENDERING

有限元分析结果的体绘制为有限元分析提供了直观、有效的方法，但有限元网格在几何上的复杂性以及拓扑上的非结构化给直接利用传统的绘制技术带来困难．这篇文章首先给出了将三维有限元网格剖分成四面体网格的方法．然后，为了便于体绘制，将网格进一步剖分成不包含空洞的凸网的集合．剖分过程用ＢＳＰ树表示，以便实现任意有限元网格的深度排序．而ＢＳＰ树的结点数不超过网格相邻边界面之间二面角小于１８０°的角的总数．同时给出了实现算法的数据结构．最后显示了实验结果．

This paper first gives a method to subdivide finite element meshes into tetrahedral meshes. For implementation of volume rendering, the generated meshes are further partitioned into sets of convex meshes without void. In order to sort final meshes in depth order, this process is represented by a BSP tree. The number of the BSP tree's nodes does not exceed the number of dihedral angles less than 180 degree's of adjacent boundary faces. Meanwhile, necessary data structures and experimented results are shown.