Recognizing shape features in solid models

A procedure for defining and recognizing shape features 3-D solid models is presented in which a shape feature is defined as a single face or a set of continuous faces possessing certain characteristic facts in topology and geometry. The system automatically extracts these facts from an example shape feature interactively indicated by the user. The resulting representation of the shape feature can be interactively edited and parameterized. Graph matching accomplishes feature recognition. The system searches the solid model for B-rep subgraphs with the same characteristic facts as the shape feature to be recognized. When the system recognizes a shape feature, it removes the geometry associated with the feature from the original solid model to produce a simpler solid model. It then examines the simpler solid model to determine whether additional features have been revealed. The process repeats until no additional features are found.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>