计算机辅助几何设计中体的一种描述方法

Description of Solid Elements in Computer Aided Geometric Design

本文对体的基本元素的参数表示法,即体元的参数表示法,三三次曲面体元以及切矢、扭失、三次混合偏导矢的几何意义作了较详细的讨论。1985年美国专家R.SGallager曾协助我们完成了包括体在内的“几何造型软件包”。

Geometric modeling is an important subject on CAGD.Because it is necessary to describegeometric solid clements in Computer Aided Design so that the problems about mechanics andengincering,especially three dimension,can be solved.But the papers or books about solid ele-ments of geometric modeling have seldom published yet in our country until now.This paper will discuss parametric expression of solid elements,tricubic solid elements ofsurfaces,tangent vectors,twist vectors,triple mixed partial,and their influence on the shape.In1985,R.S.Gallager,expcrt of Boeing Company,helped us to have designed softwares of com-puter according to above methods.