摘要
ＶＣＡＤ系统采用作用辅助线的方法即先勾划总体轮廓，然后再作细化处理输入工程图纸。系统把几何约束蕴含于数据结构之中，建立起几何元素之间的约束关系．由于作图过程的每一步骤都是确定的，每一条辅助线都只依赖于至多一个变量，因而所有计算都是局部的，封闭于每条几何定义语句的自身范围内，算法效率高、可靠性好。
VCAD system adopt the method of auxmary line,i.e. draft the overall contour at first,then do the details process to input engineering drawing,The system put the geometric con-straints into the data structure to built the constraints relationships of geometric elements.Because the every step of drawing procedure is determined, every auxiliary line only dependsto one variable at most, so all computes are local and confined to the range of every geomet-ric defination statement itself.The algorithm has a high efficiency and a good reliability.
出处
《工程图学学报》
CSCD
1994年第1期15-21,共7页
Journal of Engineering Graphics
基金
高校博士点基金
关键词
参数化设计
作图
辅助线
VCAD
geometric constraints, parametric design,geometric reasoning
