Paper-based computer-aided form sketching : a prescribed sketching language-based approach

Abstract

Due to its efficacy in rapidly externalizing form concepts, paper-based sketching is still extensively used by practising designers. It is a common practice that form concepts are sketched on paper prior to being translated into three-dimensional (3D) virtual models for further development. A critical literature review reveals that presently designers do not have adequate support in this translation process. In view of the above, this thesis proposes and develops a framework for a computer based tool aimed at integrating paper-based form sketching with Computer-Aided Design (CAD). The core of this framework is a prescribed sketching language (PSL), required to create a dialogue between the designer and the computer. PSL is based upon modelling principles commonly employed in CAD systems. It is composed of user- and pre- defined graphical elements and a set of pre-defined rules for drawing them on paper. Computer-related frames making up the framework have been implemented in a prototype tool, mX-Sketch. An evaluation of the framework from the user's and computer's perspectives has been carried out. Evaluation results revealed a positive feedback by practising designers towards the notion of using PSL to integrate traditional sketching with CAD. The evaluation also showed that PSL contributes towards the automatic translation of paper-based form sketches into 3D virtual models. At the same time, the results obtained collectively suggest that further work is required before PSL and the supporting tool can be used in design practice.