Trimmed NURBS曲面参数域的快速三角化算法

本文介绍对裁剪后的ＮＵＲＢＳ曲面参数域的一个简单、快速的三角划分算法．该算法首先对参数域进行初始划分，然后对初始划分中的每个三角形进行取舍判断或裁剪，保留参数域内的部分，丢弃参数域外的部分．为了提高速度，本算法采用了近似参数域边界线、避免无效计算及避免重复计算等措施．测试所得的数据表明，三角划分的时间与划分数成线性关系．

A FAST ALGORITHM FOR TRIANGULATING THE PARAMETRIC SPACE OF TRIMMED NURBS SURFACES

A high-speed and practical algorithm for triangulating the trimmed NURBS surfaces is introduced. In this algorithm, an initial division is done first to the parametric space, then each triangle in the initial division is judged and decided to be accepted, rejected or trimmed so that the parts inside the parametric space are reserved and the others are discarded. To speed up the triangulation, some effective measures are adopted, such as to approximate the border of parametric space and to avoid unnecessary or repeated calculations. The test data shows that the time of the triangulation is linearly relevent to the number of division.