一种有限环域裁剪多义线的算法及应用

提出了一种有限环域裁剪多义线的算法。文章首先介绍了基本概念和算法设计。该算法通过多义线与诸环求交，在求交过程中利用局部法判别有效交点，从而确定出多义线位于有限环域内的有效部分。该算法对重边和重点情形给出了简单、直观的处理方法，从而可靠地解决了裁剪过程中可能遇到的重边和重点问题。文章还给出了一个由内、外环组成的有限环域裁剪一条多义线的实例。最后，文章还介绍了该算法在两张裁剪曲面的求交算法及过渡算法中的应用。该算法已在微机上实现并测试通过，并已利用该算法实现了裁剪ＮＵＲＢＳ曲面的求交及过渡算法

An Algorithm and Its Application for Polyline Clipping Based on Finite-Loop Domain

Presents an algorithm for polyline clipping based on a multiply connected domain formed by finite loops. Some basic concepts and algorithm are explained first. With local method, the effective intersection points(in points or out points)of the directed polyline intersected with all loops are determined. The major advantage of the algorithm is to give a simple and reliable method for treating the overlap edge and multi point problems. Furthermore, an example of polyline clipping based on a multiply connected domain formed by finite loops is presented. Finally this paper introduces the utilization of the algorithm in surface intersecting and surface filleting. The algorithm has been implemented in computer, and applied to NURBS surface intersecting and surface filleting. Experimental results show that it can be used in all kinds of situations.