Falcidieno, B.Giannini, F.Porzia, C.Spagnuolo, M.2015-10-052015-10-0519911017-4656https://doi.org/10.2312/egtp.19911010A double description is proposed for the representation of a feature-based model which supports the distinction between form and functionality. This description consists of a primary representation in terms of geometric features ( geometric feature graph) and a set of feature-based representations which are created by transformations that are viewpoint specific and apply to the geometric feature graph.10.2312/egtp.19911010