Approximation of Catmull-Clark subdivision surfaces by Bezier patches

摘要

A method for converting a subdivision surface, such as a Catmull-Clark subdivision surface, into a cubic Bezier surface defined by sixteen control points. The method includes (a) converting a subdivision face to Bezier control points using a conversion matrix using fifteen points and a dummy value for an unavailable sixteenth point; and (b) replacing one of the Bezier control points which corresponds to an extraordinary point on the subdivision face with the extraordinary point's limit point.