用二次非均匀有理B样条表示圆锥曲线和二次曲面  

Representing Conic Curves and Quadric Surfaces With Quadratic Nonuniform Rational B-Splines

作　　者：张申生[1] 

机构地区：[1]上海交通大学南方CAD中心

出　　处：《计算机辅助设计与图形学学报》1989年第2期28-35,共8页Journal of Computer-Aided Design & Computer Graphics

摘　　要：本论文介绍并推导了用二次非均匀有理B样条来精确表示几何造型及CAD/CAM系统中常用的二次曲面和圆锥曲线。在这第一部分里,我们将证明二次有理B样条和圆锥曲线的等价性并用具体实例来说明权因子的确定和表达式的推导方法。Conic curves and quadric surfaces are widely used in CAD/CAM applications. Two parts paper present a way to represent these items using quadratic aonuniform rational B-splines ( NU RB). In the first part, we prove the identity between quadratic non-uniform rational B-splines and co nic curves and shov how to determine a specified NURB representation as well as its weighting fac tors hi by detailed examples.

关 键 词：B样条 圆锥曲线 CAD CAM 几何造型 

分 类 号：TP391.7[自动化与计算机技术—计算机应用技术]