A shape specification system based on fuzzy logic is proposed, which aims to facilitate designers in conceptual design stage by allowing them to specify and work with rough models in a more intuitive fashion. The system uses a 3D object representation called 'parametric geons' which provide both qualitative and quantitative descriptions, in addition to global shape constraints, via eight shape parameters. Geometric descriptors and aesthetic descriptors are introduced and their fuzzy membership functions are constructed. Inference rules are obtained to link these descriptors with shape parameters. The system which models after designers' behaviour, allows designers' own aesthetic terms and interpretation of shapes to be added, and a library of successful designs with appropriate fuzzy descriptions to be constructed for later use.
B. Pham