Extracting Silhouette Curves of NURBS Surfaces by Tracing Silhouette Points  

作　　者：李学军 孙家广 杨长贵 

出　　处：《Tsinghua Science and Technology》1998年第2期59-62,共4页清华大学学报（自然科学版（英文版）

摘　　要：Extracting silhouette curves is a key part of hidden curve removal algorithms. It relates directly to the quality of graphics generated by the algorithm, and to the speed and space efficiency of the algorithm. This paper proposes an algorithm for extracting silhouette curves that numerically determines the starting and ending silhouette points, then traces each starting point to obtain the whole silhouette curve. Silhouette loops are obtained by tracing silhouette points on isoparametric lines. This algorithm is suitable for extracting silhouette curves at any given tolerance without surface subdivision.The algorithm is fast and requires minimal storage space.Extracting silhouette curves is a key part of hidden curve removal algorithms. It relates directly to the quality of graphics generated by the algorithm, and to the speed and space efficiency of the algorithm. This paper proposes an algorithm for extracting silhouette curves that numerically determines the starting and ending silhouette points, then traces each starting point to obtain the whole silhouette curve. Silhouette loops are obtained by tracing silhouette points on isoparametric lines. This algorithm is suitable for extracting silhouette curves at any given tolerance without surface subdivision.The algorithm is fast and requires minimal storage space.

关 键 词：hidden curve removal NURBS surfaces silhouette points silhouette curves 

分 类 号：TH765.2[机械工程—仪器科学与技术]