复合三角Bézier曲面求交和裁剪的实现

Procedure of Intersection and Trimming for Composite Triangular Bézier Surface

该文利用三角Béier曲面片的可分割性，解决了迭代收敛、初始交点算计问等题；通过近曲面点、边界点跨越等过程，实现了由一个初始交点将跨越许多曲面片的整条交线跟踪出来的设想．将各交点作为型值点插入曲面中，对三角网格进行三角再划分，以交线为界进行三角网格和型值点的分离，最后重新生成两张复合曲面，实现了裁剪的目的．测试结果显示，此方法简单、可靠，能够满足曲面造型的要求．

Using the splitting property of tringular Béier patch, the problemss of iterating and initial intersec-tion point calculating can be solved. By the procedures of near surface point iterating and border points travers-ing, the whole intersection curve traversing many patches can be traced from one initial intersection point.lnserting intersection points as measure points into surface, retriangulating grids, splitting triangular grids andmeasure points along intersection curve, the original surface can be trimmed into two composite triangularBéier surfaces. The experimental results show that this method is simple, robust and applicable for surfacemodeling.