摘要
超二维环境的最大特点在于使用了二维数据表示三维模型，实现了不建立三维模型直接对三维模型的各向投影进行参数设计，直接修改复杂工程图。由于相对三维工程实体，纯二维数据信息量不足，而按以往方法用多视图来弥补，又因视图间缺乏必要联系，无法建立和描述三维信息，因而，超二维模型引入视图投影信息，使之具有一定的三维信息。通过结合当前尺寸驱动和参数设计的现状，在超二维环境下，引入高等画法几何学多视图间的投影原理，借鉴特征造型的思想，从数学原理、几何建模方式、约束传播机制等关键点上，提出了一套基于视图投影和画法几何推理的参数设计方法，并在奇特超二维参数绘图（ＣＩＴ－Ｓｄｒａｆｔ）系统得以应用。
The merit of Super 2D is using 2D data to establish 3D model.Therefore parametric design can be realized without the 3D model,and a complex multi view engineering drawing can be generated and maintained with minimum efforts.In traditional 2D CAD systems,the data and geometric models are purely two dimensional,they have not enough information to understand the meaning of their 3D data model.If using multi view,they can not support the dimension driven parametric design functionality because there are no necessary relations between views.So in the Super 2D environment,we use the engineering graphics standards and the projection rules of descriptive geometry to make 2D data having certain 3D information and to establish relations between different views.This paper presents a whole set of methods to support dimension driven parametric design based on the advanced descriptive geometry theory,and makes deep research on the mathematical thoery,geometrical modeling and constraint transformation.We try to provide a new thought in the CAD field.
出处
《计算机辅助设计与图形学学报》
EI
CSCD
北大核心
1997年第4期349-355,共7页
Journal of Computer-Aided Design & Computer Graphics
关键词
参数设计
超二维环境
工程设计
super 2D,parametric design,transformation matrices,viewports information,constraint.
