Abstract
The solution to the self-intersection of a swept volume is the bottleneck to the geometric modeling of a moving object. Self-intersection of a swept volume is the result of an object, which is called a generator here, moving into a space which it previously occupied. A graphical solution is devised in this study. It consists of following steps. First of all, a candidate swept volume is created by warping a series of characteristics curves on the boundary of the generator in a given time domain. The result is the facet model of a swept volume. Secondly, a series of sectioning operations to the candidate swept volume are performed where the sectioning planes are parallel. If self-intersection exists for a given candidate swept volume, some of the resulting polygons (cross-sections) after the sectioning operations are complex polygons. Thirdly, an algorithm is proposed here to convert these polygons into sweep contours, which are simple polygons. A well defined facet model of the swept volume is then obtained by fitting the corresponding sweep contours with a surface.