Object contours in virtual conceptual sketches - modelling of perception

The virtual product model in its different stages is an essential pre-requisite for the virtual modelling of processes and their virtual simulation. Product design starts with conceptual design including the concepts for shape and function - the gestalt. In this stage, the conceptual designers work on fuzzy product data applied to perception modelling and shape creating. Fuzziness means different aspects: the shape of the product is interpreted in scribbles which define the appearance and the function of the product representing a "frozen movement" more than the object contour itself. In this paper we will suppose a method to create virtual object contour models out of scribbles that construe the perception of the subject. The mathematical basis for the later virtual sketches is given by interval fuzzy-splines. The method combines an image-based modelling system with usual Computer-Aided Design (CAD) modelling strategies.