Extension of the Fully free-Form deformation Features to planar functional Areas

Classical CAID (Computer Aided Industrial Design) tools are lacking methods to manipulate/modify high-level shape entities, associated to semantics. Feature-based modeling answers to these needs and the Fully Free-Form Deformation Features apply this approach to shapes defined by free-form surfaces. In this paper we propose to extend their capabilities to deal with both free form and functional surfaces (like plane, cylinder, sphere...), which are extensively used and mixed in aesthetic and engineering designs. A method for the insertion of planar surfaces, suitable to handle the uncertainty in the first draft of the product, is here proposed. The approach does not provide effective precise functional surfaces, but is able to introduce region resembling such behaviour in a free form surface, avoiding the need of trimming operations, thus allowing more efficient shape alternative generation and evaluation.