关键词: 横截面, 蒙皮, 裁剪, 分支曲面, 算法, 非均匀有理B样条, 曲面重构

Abstract: Surface reconstruction is significant in Computer Aided Design (CAD) and reverse engineering. A new approach of constructing solid branching surface model using Non-Uniform Rational B-Spline(NURBS) theory based on parallel contours was proposed. According to different relationships among adjacent contours, it could be divided into three cases, such as “one to one”, “one to many” and “many to many”. In the case of “one to one”, a surface patch could be constructed by skinning method. To construct surfaces from “one to many” contours, the more “one to one” relations were exchanged from “one to many” case, from which envelope planes were constructed accordingly. After surface trimming, 4-sides Coons filling, one branching surface was reconstructed. In the case of “many to many”, two “one to many” relations were converted from it to construct surface. By skinning multi-adjacent “one to one” relationship, the smoothness of the reconstructed surface was improved. And the extra-time of optimization was avoided by adding direction traverse. Complexity of constructing surface was reduced after translation from “many-to-many” case into two “one-to-many” case. Through adjusting the parameter, controlling of the position and width of the mid rip were realized. It provided controlability for shape of the reconstructed branch surface.

Key words: cross sections, skin, trimming, branching surfaces, algorithm, non-uniform rational B spline, surface reconstruction