Similarity Test for Free-form Surfaces in Product Design: AnIntegrated Approach

摘要

Three dimensional free-form surfaces, widely used in CAD/CAM systems, allow users to design andrnmanufacture 3D objects of greater complexity. An integrated approach is proposed to find the level ofrnsimilarity given two free-form surfaces with substructures. First, the Gaussian curvature values of eachrnsurface are mapped into the two-dimensional space, and a shape-based measure is obtained using statisticalrnmethods to represent the level of similarity. Second, the comparison of substructures provides additionalrninformation about shape and topology, and assists in improving the shape-based measure iteratively. Thisrnapproach can be applied to surfaces under various transformations, and shows potential associations amongrnsurfaces belonging to a single product design, or from different ones. The proposed method can be used torndevelop data mining techniques for large product databases, and tools for copyright protection of CADrnmodels are expected to evolve.