摘要
NURBS曲线曲面形状修改一直是CAGD中的关键技术之一。本文针对NURBS曲面的几何特征修改,提出了基于约束优化的修改方法。通过对NURBS曲面的控制顶点进行扰动,以曲面控制网格变化量为目标函数并使之最小化,实现了NURBS曲面上给定一点处的位置、一阶偏导矢、二阶偏导矢和法矢等几何特征的修改。数值实例表明该方法用于微调时,可实现对曲面局部形状的多种修改效果,便于交互设计。
Shape modification of NURBS curves and surfaces is one of the most crucial techniques in CAGD. In this paper, a method via constrained optimization is given to modify the geometric features such as position, partial derivative or normal vector of the selected parametric point on the given NURBS surface by minimizing the changes of control net. The numerical examples show that this method can realize miscellaneous modification effects and is convenient for interactive design.
出处
《西安邮电学院学报》
2008年第3期133-135,157,共4页
Journal of Xi'an Institute of Posts and Telecommunications
关键词
NURBS曲面
约束优化
几何特征
形状修改
NURBS surfaces
constrained optimization
geometric features
shape modification
