Non-regularlized Boolean set operations on non-manifold b-rep objects

For Boolean operations on geometric models, we have developed an intersection algorithm for non-manifold boundary models with vertices, linear edges, planar faces, and volumetric regions. The algorithm operates by intersecting entities in an ordered manner, from vertex to edge, then to face elements, in contrast to intersecting pairs of faces as in two-manifold boundaries. Singular intersections are systematically handled by determining if an entity in one object is within a tolerance region of the entity in the other object. Two-manifold objects, i.e. solids, and nonmanifold objects represented with the vertex-based data structure, which is designed for nonmanifold representation, are handled by the same intersection algorithm. An implementation of the proposed algorithm and the experimental results are also discussed. This research was supported in part by the Engineering Design Research Center, an NSF Engineering Research Center at Carnegie Mellon University UNIVERSITY LIBRARIES CARNEGIE MELLON UNIVERSITY PITTSBURGH, PA 15213-3890