Declarative user-defined feature classes

Designing mechanical parts using a feature vocabulary is a very effective and rich paradigm. Its expressive power, however, is severely limited if the set of feature types available in a feature library is fixed. It is, therefore, desirable to be able to extend and configure a feature library according to particular requirements, either of an end-user of a CAD system or of an application area. These requirements are not limited to topologic and parametric aspects of a generic feature definition, but include also validity conditions to be verified for each feature instance in a model. This paper proposes a new declarative scheme for the definition of feature classes . This scheme provides a unified description of the shape and validity issues of a feature class, as well as a flexible configuration of the feature class interface. In the definition process, the various constraint classes available play a central role, whereas an inheritance mechanism structures the feature library hierarchy. At the end of the process, validation of the class is performed, in order to avoid over- and underconstrained specifications. A graphical user interface supports the whole feature class definition process. Once defined, a feature class is automatically made available for use in a feature library of the modeling system.

@InProceedings { BINB98a,
  author       = "Bidarra, Rafael and Idri, A. and Noort, Alex and Bronsvoort, Willem F.",
  title        = "Declarative user-defined feature classes",
  booktitle    = "CD-ROM Proceedings of the 1998 ASME Design Engineering Technical Conferences",
  month        = "sep",
  year         = "1998",
  publisher    = "ASME, NY",
  address      = "Atlanta, GA",
  url          = "http://graphics.tudelft.nl/Publications-new/1998/BINB98a"
}