| In this paper, considering the actuality of packaging Indus-try, 3-D packaging CAD software system , satisfying the special application in pac kaging industry, has been put forward and des-igned.Studying works are as follows:(1)With the Radial Edge Data Structure, the description of ob-ject in computer memory is provided. The seven forms used to de-pict body in computer memory are analyzed and paralleled. The Bo-rder expression is utilizedas the primary data structure in th-is model system. In addition, the Radial Edge Data Structure is used as central data structure.(2)The Shadow Algorithm for the hidden part in object is com-pleted. T he causation of invisible lines and faces is also anal-yzed. It is reali zed that the invisible part of the object can be shadowed, using the Max imum or Minimum Enveloping Rectangle Method and the Counter of Points of Intersection Method, etc.(3) The Boolean Operation between integrity or unintegrity bodys is supplied. On the basis of set operation on integrity bo-dy, taking advantage of the excellency provided abundant topolo-gical information by the Ra dial Edge Data Structure, applying the Divide and Conquer Method for inha ncing the efficiency of the system, the Boolean Operation on integrity or unintegrity bodys is furnished.
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