基于有向超图的参数代表示模型及其实现

A NEW PARAMETRIC GEOMETRY MODELING AND ITS IMPLEMENTATION

本文提出了一种基于有向超图的参数化图形表示模型．它不仅能够表示图形的尺寸约束和几何约束，而且能够支持图形拓扑结构变化和工程设计约束的表示．在交互绘制图形对象的同时直接建立参数化图形约束模型．由于在图形构造的每一步都保证约束的一致性，因此，不会出现过约束或欠约束的情况．经实践表明，该模型具有实用方便、高效可行的特点，适合于系列化产品的参数化ＣＡＤ系统建模和绘图．

A new parametric geometry modeling based on directed hypergraph is described in this paper. It can support the representation of dimensional constraints and geometric constraints. Moreover, the geometric structure changes and design constraints can also be solved. The parametric geometry modeling is finished while interactively constructing geometric objects. The constraint consistency is insured by construction steps. Overconstrained or underconstrained sketches can not take place. The implementation suggests that the modeling is practicable and convenient for parametric designs. It can be used to realize products oriented parametric designs and drafting.