Bezier surface/surface intersection

The computational requirements and accuracy of two methods for finding the intersection of Bezier surfaces are examined. In both methods, the existence of an intersection curve is confirmed by using the convex hull property of such surfaces. The first method evaluates the intersection by recursive subdivision of two patches with overlapping hulls. The second method detects a point on the intersection curve and then incrementally traces the intersection in the parametric spaces of the two surfaces. With both methods, the intersection of a pair of first-order planar patches must be solved analytically. The intersection is approximated by first-order Bezier patches in the first case and by planar triangles in the second. Overall, the method of incremental tracing is shown to give more accurate results than the method of recursive subdivision