椭圆型Offset曲线及其应用

An Ellipse-Liked Offset Curve and Its Application

针对 Sweep曲面中形变控制的需要 ,提出了一种椭圆型 offset曲线 ,并讨论了它的性质 .为了便于造型系统的一致性表示 ,给出了椭圆型 offset曲线的 NURBS逼近表示算法 .最后给出了它的应用实例 ,并在自主开发的几何造型系统 GEMS 5 .0中实现 .

In this paper, on type of general offset curve, an ellipse liked offset is introduced to satisfy the smooth deformation control in the swept surface, and its properties are discussed. Furthermore, considering the compatibility with the data structures and algorithms of the geometric modeling system, this paper presents an offset approximated algorithm with NURBS curve. Finally, the reasonableness and the robustness are verified by many examples, which have been implemented in the commercial geometric modeling software GEMS 5.0 developed by Tsinghua University.