三角网格上细分曲面的尖锐特征造型

尽管光滑性是我们在自由曲面造型时的最主要的目标，在某些特定情况下却需要产生非光滑的特殊效果，如折痕、角、尖刺、锥等尖锐特征。本文主要研究基于Loop格式的尖锐特征的生成。一种基于网格拓扑结构的修改的方法把诸如折痕、角、尖刺、锥和交点的生成统一了起来，同时第一次由本文生成了多条折痕交点的特殊效果。实例表明由本文中方法生成的尖锐特征效果非常好。

Sharp Features of Subdivision Surfaces over Triangular Meshes

Though the smoothness of surfaces is one of the main requirments in free form surface modeling, non-smooth effects such as sharp features are required in some occasions. Generation of such sharp features based on Loop's subdivision scheme is investigated in this paper. A method based on the construction of mesh topology is presented to unify the generation of the sharp features such as crease, corner, dart, cone and cross into boundary processing. Especially, we create cross effects for the first time. Examples are provided to illustrate the effects of the sharp features generated by the method.