The implementation of a sketch-based virtual product development

Within the product development process, working in virtual environments is generally applied. Thus, the digital product model in its different stages is an essential prerequisite for the virtual modeling and simulation of manufacturing processes. Product development starts with conceptual design including the concepts for shape and function. The conceptual designers work on fuzzy product data applied to perception modeling and shape creation. For some time now, there has been a strong demand to define creative human problem solving in conceptual design as a task of virtual product development and to assist the process simultaneously through the use of appropriate digital models and virtual methods. This paper reports on R&D results concerned with integration of the process of conceptual design based on traditional aids, such as freehand paper sketches, in virtual environments. Until now, it has not been possible to work iteratively with both freehand sketches and digital product models. This paper describes how to interpret product descriptions in freehand sketches and to transfer them to digital three-dimensional models, e.g. in order to visualize, calculate and evaluate shapes to the development of computer-aided design (CAD) models. The methods combine an image-based modeling strategy with conventional CAD modeling strategies.