Automatic extraction of quadric surfaces from wire-frame models

The automatic conversion of 3D wire-frame models to boundary representation solids is very important for the one-off conversion of line drawing to sol id modeling system. In this paper, a minimum internal angle (MIA) algorithm that efficiently finds all quadric surfaces in a wire-frame model is propo sed. It requires considerably less searching time than depth-first search t hat could grow exponentially in complexity. In addition, the proposed metho d is advantageous in easy description of the geometry of the traced surface s when compared to other methods. (C) 2001 Published by Elsevier Science Lt d.