An edge matching technique for non-planar face intersections in geometric parametric models

In current feature-based parametric design systems the reusability principle is not as fully supported as it should be. Both unpredictability and ambiguity of models often happen during design modification within one system. This reference deficiency significantly reduces the power of feature-based parametric modeling, where geometry reevaluation generates some unexpected topology, especially when considering edges.We propose in this paper a new edge matching method resulting from the intersection of non-planar faces. This method considers the matching between edges as a geometric transformation which overlays edges of the initial model on edges of the reevaluated model. It finds, among all possible edge mappings, the one which represents the design intent as close as possible. In order to find the right mapping, it quantifies the relevance of each mapping. Moreover, in addition to the edges resulting from the intersection of the same pair of faces, this method uses ldquovirtual edgesrdquo for solving some ambiguous cases.