DECOMPOSING SOLID MODELS INTO DEPRESSION AND PROTRUSION FEATURES

In this research, an efficient and robust algorithm is proposed to decompose a boundary-represented solid into depression and protrusion features. Those extracted features may provide useful and direct information for applications, such as sheet metal flattening and surface machining. At the beginning, the boundary of a solid is decomposed into depressions by removing convex edges. Since those depressions may include local protrusions, the protrusions are extracted by further decomposition of the decomposed depressions by removing concave edges. In addition to the above procedures, depressions can also be composed into global depressions according to their connections to give higher-level depression features. Using a solid modelling system with the half-edge data structure, this algorithm is implemented on a feature decomposition system.