Designers usually start their design process by exploring and evolving their ideas rapidly through sketching since this helps them to make numerous attempts at creating, practicing, simulating, and representing ideas. Creativity inherent in solving the ill-defined problems (Eastman, 1969) often emerges when designers explore potential solutions while sketching in the design process (Schön, 1992). When using computer programs such as CAD or Building Information Modeling (BIM) tools, designers often preplan the tasks prior to executing commands instead of engaging in the process of designing. Researchers argue that these programs force designers to focus on how to use a tool (i.e. how to execute series of commands) rather than how to explore a design, and thus hinder creativity in the early stages of the design process (Goel, 1995; Dorta, 2007). Since recent design and documentation works have been computer-generated using BIM software, transitions between ideas in sketches and those in digital CAD systems have become necessary. By employing sketch interactions, we argue that a computer system can provide a rapid, flexible, and iterative method to create 3D models with sufficient data for facilitating smooth transitions between designers’ early sketches and BIM programs.
This dissertation begins by describing the modern design workflows and discussing the necessary data to be exchanged in the early stage of design. It then briefly introduces the modern cognitive theories, including embodiment (Varela, Rosch, & Thompson, 1992), situated action (Suchman, 1986), and distributed cognition (Hutchins, 1995). It continues by identifying problems in current CAD programs used in the early stage of the design process, using these theories as lenses. After reviewing modern attempts, including sketch tools and design automation tools, we describe the design and implementation of a sketch and multi-touch program, SolidSketch, to facilitate and augment our abilities to work on ill-defined problems in the early stage of design. SolidSketch is a parametric modeling program that enables users to construct 3D parametric models rapidly through sketch and multi-touch interactions. It combines the benefits of traditional design tools, such as physical models and pencil sketches (i.e. rapid, low-cost, and flexible methods), with the computational power offered by digital modeling tools, such as CAD. To close the gap between modern BIM and traditional sketch tools, the models created with SolidSketch can be read by other BIM programs. We then evaluate the programs with comparisons to the commercial CAD programs and other sketch programs. We also report a case study in which participants used the system for their design explorations. Finally, we conclude with the potential impacts of this new technology and the next steps for ultimately bringing greater computational power to the early stages of design.Ph.D
