基于STL的约束不完全Delaunay四面体剖分

Partianlly-constrained delaunay tedrahedrizations using STL file

基于STL(STereo Lithography)文件描述的实体造型,应用插入多边形操作技术对实体表面进行二维Delaunay三角网格剖分,形成空间离散点集和新的约束边界;采用换面操作方法实现离散点集的Delaunay四面体构型;采用四面体外接球心和内切球心加权平均的坐标点加密四面体网格;在边界恢复操作中,采用2D-3D联动优化的方法实现边界一致性恢复,对难以恢复的局部区域,放弃Delaunay空球准则,进行特殊处理,从而实现表面约束的不完全Delaunay四面体剖分.实例表明所提出的算法具有很好的适应性.

The surface of a 3D solid modeling described by STL （STereo Lithography） file was dissected as 2D Delaunay triangles by inserting polygon procedure to form new imposed constrained boundary and initial 3D point sets. Then, exchanging face operation is employed to construct tetrahedral configuration based on the 3D point sets. Finally, the 2D-3D associated optimizing method is used to restore the boundary. And, a special approach that throws away the 3D Delaunay triangulation criterion is presented to deal with the local domains that are difficult or impossible to be restored. The example shows a good flexibility of the presented method.