3D Sketching with Fully Free Form Deformation Features (d-F4) for Aesthetic Design

This paper addresses the designers' activity and in particular the way designers express an object shape in 2D sketches through character lines. The tools currently available in commercial CAS/CAD systems to manipulate the digital models are still not sufficiently suited to support design. In this paper, we introduce the so-called Fully Free Form Deformation Features (?-F4), able to take into account the curve-oriented stylists' way of working. Both the advantages of a free form surfaces deformation method and a feature-based approach are merged to define high level modelling entities allowing for a direct manipulation of surfaces through a restricted number of intuitive parameters. In addition, a ?-F4 classification is proposed to permit a fast access to the desired shape according to its semantics. The proposed approach is illustrated with some examples.