CAD系统中产品设计三维实体建模方法的研究

三维建模是应用CAD系统进行产品设计的重要步骤。现在市场上已有不少的CAD系统，但是不同系统中的三维建模方法却是基本相同的。在这些三维建模的方法中，往往对用户施加了许多的限制，使得用户无法建立复杂的三维实体。笔者提出了一种新的三维建模方法－折叠法，应用这种方法的概念和原理，可以开发出先进的三维建模CAD系统。折叠二维平面图形构成三维实体是作者提出的一种新概念。

The Research on 3D Modeling Methods for Products Design by CAD Systems

3D modeling method is one of the most important techniques in product design with computer-aided design systems. The methods for 3D modeling which are used in different kinds of CAD systems are nearly the same in principle. Due to the constraints that are often exerted to the users we can hardly construct complicated 3D objects. A new concept for 3D modeling called folding is proposed in this paper. With the principle of the new concept we could develop advanced 3D modeling method in CAD systems. It is a key point of this paper that a 2D graphics is folded into a 3D solid.