Drawing standards for early design: where do we stand?

Despite the availability of Computer-Aided Design (CAD) systems, paper-based sketching is still widely used during conceptual design due to its efficiency in externalizing form solutions. The main reason attributed to this is that the user-interface of most CAD systems follows the WIMP (Windows, Icons, Menus and Pointing device) paradigm which does not support freehand form sketching as input on normal paper. Yet CAD systems still offer advantages for early form design such as three-dimensional (3D) model visualization. Thus designers would greatly benefit if the advantages of manual sketching are combined with those of CAD. However, due to various factors, such as the idiosyncratic style of sketching, computer processing of hand-made sketches becomes difficult. At the same time, although drawing standards are available for detail design, standards for early form sketching are unavailable. To address the above issues, this paper reports on-going research aimed at providing a drawing standard to seamlessly link early form sketching on paper with 3D modelling technology. The paper provides an overall picture of the state-of-the-art approaches to early form sketching. A drawing standard has been developed to address the identified deficiencies of current approaches. The developed standard specifies what is required both for the process of drawing and the representation of form in the resulting drawing, i.e. the early form sketch. Besides from providing 3D models directly from paper sketches, such a standard has been found useful for collaborative design. Evaluation results indicate what aspects of the proposed drawing standard require improvements.