一种特征造型的拓扑元素命名机制

特征造型是CAD系统的关键技术,而拓扑元素命名机制是特征造型最根本的问题之一.提出一种以特征为基础,对特征实体的面进行统一命名的方法,并在此基础上对特征实体的边和点进行命名.特征名在建模过程中保持不变,从而实现在模型编辑过程中对拓扑元素的正确记录与维护.针对拓扑边的分裂及曲面相交产生多条交线的问题,给出了参考线的概念及定义原则,有效解决了对分裂边及多交线的区分与引用问题.

Mechanism of Naming Topological Entities in Semantic Feature Modeling

Feature modeling is the key technique in CAl)system, and topological entity naming is one of the essential issues of feature modeling. A feature-based method was proposed to name the surfaces of feature entities, then name edges and vertices of feature entities. Because of invariance of feature name in process of modeling, topological entities can be correctly recorded and maintained in model editing. The conception of reference line and its definition principle were proposed to solve topological edge splitting and multiple intersecting curves generated by two surfaces, which can identify and refer the splitting edges and multi-intersections efficiently.