Doo-Sabin细分模式的尖锐特征造型

Sharp Feature Modeling of Doo-Sabin Subdivision Scheme

通过推广准均匀二次B样条的节点插入算法,对边界面、折痕面、角点面等特征面给出新的细分规则,从而使Doo-Sabin细分模式可以表示边界、折痕、角点、刺点等尖锐特征,且特征处不受拓扑结构的限制·在特征附近进行了连续性分析,所得到的极限曲面具有分片G1连续性·该算法既可以设计有特征的、任意拓扑的复杂曲面,又可以精确地表示球面、柱面、锥面等工程技术中常用的二次曲面,在CAD/CAM领域具有广泛的应用前景·

By generalizing knot-inserting algorithm of quasi-uniform quadratic B-splines, subdivision rules for Doo-Sabin scheme in feature faces, such as boundary faces, crease faces and corner faces etc, are presented and sharp features, such as boundaries, creases, darts and corners can be generated without any topology constrains. Continuity analysis near these features shows that the resulting limit surfaces are of piecewise G^1 smoothness. Complicated surfaces of arbitrary topology with sharp features and quadratic surfaces frequently used in engineering, such as spheres, cylinders and cones, can also be accurately represented, which indicates the broad applicability of our method in CAD/CAM fields.