摘要： 为实现CAD/CAM的集成化,必须改进传统的实体造型方法。本文用特征体素代替形状特征,讨论了利用特征体素进行特征实体造型的方法。在比较二叉树和二层树结构的基础上,认为二层树结构更利于特征实体造型;提出了二层树CSG和 B-Reps的混合数据结构;研究了二层树结构 CSG模型一维布尔运算的快速算法,并给出了在图形显示应用中的实例。

Abstract: Conventional solid model needs to be changed in order to implement integrated CAD/CAM. Feature primitives replace form feature in this paper. Feature solid modelling by means of feature primitives is discussed. On the basis of comparison between binary tree CSG and two-level tree CSG, the former is considered as the one favourable for feature solid model. Hybrid two-level tree CSG/B-Reps data structure is proposed. The one-dimensional boolean evaluation algorithm for two-level CSG model is explored and its application in the shading image processing is implemented.