Loop detection in surface patch intersections

Abstract

A condition is presented for guaranteeing that all branches of the curve of intersection of two parametric surfaces patches contain a point on at least one of the patch boundary curves. This is of value because it eliminates a robustness limitation which arises when computing surface intersections using the marching method, namely, assuring that all branches of the intersection curve have been found. The intersection curve of any two surface patches meeting the prescribed condition can be computed by locating points where patch boundary curves intersect the opposing patch, and then using those points as starting points for the marching algorithm.