Form Features Recognition in a Multi-Level Representation Context

In this paper we propose a system for the automatic extraction and representation of form features in the framework of solid modeling that can be used in different contexts of application.This system works in two steps. The first step starts from a boundary model of an object and identifies the so-called generic shape features by considering only their geometric and topological aspects. These features are subdivided into two general classes, protrusions and depressions, extracted as solid volumes and arranged in a multi-level structure. This representation, called Attributed Structured Face Adjacency Hypergraph (ASFAH) is able to represent the recursive decomposition of an object in its main shape and the set of its form features (possibly compound). In the second step the identified features are classified according to the functional meaning in the application context. Thus, the hierarchical representation is reorganized by gluing and/or grouping sets of shape features which are functionally related in the considered context.