基于光顺准则的软组织模型切割

软组织模型的切割是虚拟手术中的一个重要组成部分，传统切割方法的重点在于用较短的时间将网格进行分裂，这样往往忽略了切割后网格单元的质量，为后续的变形计算埋下了隐患。本文提出了改进切割方法，按照切割交点与其周围四面体单元的拓扑关系，采用光顺性规则对切割交点和相邻单元进行调整，提高了网格的质量。基于肝脏四面体模型的切割结果表明，与传统的最少单元法相比，改进后的切割方法在满足虚拟手术实时性要求的同时，能够有效地提高切割后网格单元的质量。

Soft Tissue Cutting based on Smoothing Rule

The soft-tissue-cutting plays an important role in the virtual surgery.The traditional cutting methods are fo-cused on dividing the mesh with a relatively short time,and in most cases the element quality of the resulting mesh is ig-nored which could bury some hidden troubles to subsequent deformation computations.In this paper,an improved element subdividing method is proposed.The mesh quality is modified by adj usting the positions of the cutting intersections and ad-jacent tetrahedral elements,based on the smoothing rules.Compared to the traditional minimal new element creation meth-od,our improved method demonstrates the better quality of the resulting meshes through several examples,while meeting the real-time demand.