Why CAD tools benefit from a sketching language

Abstract

Despite the fact that Computer-Aided Design (CAD) tools are used during the early design stages to aid external representation with the generation of 3-dimensional (3D) models, paperbased freehand sketching is still the most intuitive method used amongst practicing designers due to its efficiency in externalising conceptual design solutions. Sketch recognition systems are therefore being developed with the aim to bridge the gap between freehand sketching and CAD tools. However, given the intrinsic ambiguity and incompleteness of freehand sketches, it is almost impossible to achieve the complete automatic generation of a 3D model from any hand-made sketch. Thus, one of the key research tasks in the development of sketch recognition systems concerns the exploration of sketching methods which are able to handle the trade-off between the preservation of manual sketching freedom and the ease of computer recognition. Based on this approach and as a step towards integrating 'paper-based' freehand sketching with CAD tools, this paper discloses the development and evaluation of two preliminary 'sketching languages' that support the generation of a virtual component model for further processing by computational product development tools. Furthermore this paper reports the findings of a survey which reveal that future CAD tools benefit from a sketching language.