中文摘要：

借鉴offset曲线去除自相交的方法提出了一种去除sweep曲面自相交的方法．首先根据sweep曲面上的点到脊线的距离来判断是否产生自相交；然后确定自相交候选区间集，并去除自相交点集．该方法可以推广到一般曲面与sweep曲面的求交，也可以推广到sweep曲面的offset操作中．在北京大学自主开发的几何造型系统PUM2．0中，通过大量的实例验iET该方法的稳定性和有效性．

英文摘要：

The trimming of sweep surfaces, referring to the estimation of points ostensibly on the boundaries that actually lie in the sweep surface interior, is an important problem for geometric modeling. Inspired by the trimming techniques developed for offset surface, efficient methods for both local and global trimming of sweep surfaces are proposed in this paper. The methods can also be used to compute the intersection between a freeform surface and a general sweep surface, or between offset of sweep surfaces. The efficiency and advantages are verified by examples obtained by geometric modeling software PUM 2.0 developed by Peking University.