: Ovtcharova, J.

Abstract
This paper proposes a data scheme for feature-based design consisting from four hierarchical levels. The top level reflects the designer's view on the application of a product part and consists of specifications of application features. At the second level, form features are usually defined as generic shape configurations which have no application-specific meaning and no presumptions to the kind of representation. The third level is concerned with the internal representation of form features in different ways and the fourth level - with their geometric evaluation using conventional geometric modeling techniques. The data relationships occurring in the scheme are performed by mappings in top-down and bottom-up fashion. (IGD)