基于活动约束系统的变量化设计

在变量化设计过程中设计对象可以看作是一个几何约束系统，这个系统由几何元素以及作用于几何元素之间的各种约束关系构成。一个复杂的设计对象所对应的几何约束系统往往包含大量几何元素和约束关系，如果不加区别地把所有的几何元素和约束关系纳入变量化求解的范围，则很难满足交互设计的需要。而另一方面几何约束系统又往往是稀疏系统：（1）作用于任一几何元素的约束很少；（2）与任一约束相关的几何元素很少。基于这一事实给出了一种预处理策略从原始几何约束系统中搜索得到一个规模较小的活动约束系统，变量化求解在活动约束系统上进行。该方法已在自行研制的参数化造型系统GEMS5．0中实现。

Variational Design Based on Active Constraint System

A design object can be described as a geometric constraint system in variational design, which is composed of a set of geometric elements and a set of constraints. A complex geometric constraint system usually includes a lot of geometric elements and constraints. If all of the geometric elements and constraints are considered in the variational solving, it is difficult to meet the requirement of interactive design. Fortunately most of geometric constraint system are sparse: (1) few constraints on one geometric element; (2) few geometric elements in one constraint. Based on this fact,a pre-process strategy is proposed. Construct an active constraint system from the original geometric constraint system and the variational solving is performed on the small active constraint system. This pre-process method is already applied to the parametric modeling system GEMSS.0.