This provide a basis for further application such as feature editing and so on . unlike traditional method which modifies b - rep or csg to adapt feature - based modeling , the feature - based represent model for the product which based on identifying system is presented . the represent method need not change the b - rep of solid model and can map feature - based model to b - rep - based model 不同于通常的对边界表示法或csg法进行改造的模型表示方法,提出了一种基于标识子系统的特征表示模型,一个零件的特征表示模型和其低层的几何实体模型通过标识子系统进行映射,从而不必修改现有的边界表示模型而能满足特征造型的需要并能充分利用已有的实体造型功能。
From the practical view , this paper summarizes the theory of orthogonal projection based on the first - angle projection , the ways of manual reading drawings and discusses the problems relevant . the mechanism similar with csg is used to reconstruct 3d object with priority to csg and aid by b - rep 本文从实用的角度出发,总结了正投影工程图中的投影理论基础、人工读图方法以及注意的相关问题,采用了以csg方法为主, b ? rep方法为辅,类似于csg建模的机制来实现二维视图的三维重建过程。