摘要
圆弧的表示一直是计算机辅助几何设计关心的问题,而圆弧仅是椭圆的特例。现有的方法对于椭圆弧的表示并未进行深入的研究。本文给出的三次NURBS表示大于180度椭圆弧的实用方法,克服了三次有理Bezier曲线只能表示不超过240度的椭圆弧的条件。该方法给出的控制顶点和权因子的计算结果。符合对椭圆弧NURBS表示的要求,为工程应用NURBS表示椭圆弧曲线提供了方便。
Representation of a circular arc plays an important role in CAGD. Circular arc is only the special case of elliptic arc. However, the existing methods do not work in the thorough research to circular arc. This paper presents a method for cubic NURBS representation of elliptic arc whose radian is more than 180 degrees. The method overcomes the restricted condition that the radian of cubic rational Bezier elliptic is less than 240 degrees. The calculated results of control points and weights given by the method meets the demands of elliptic arcs NURBS representation. The method is convenient for elliptic are to be used on NURBS in engineering application.
出处
《陕西理工学院学报（自然科学版）》
2007年第1期49-52,共4页
Journal of Shananxi University of Technology:Natural Science Edition
关键词
固定切向分割
形状不变因子
NURBS
椭圆弧
subdivision of tangent direction of immobility
invariable weights of shape
NURBS
elliptic arc.
