Aligning Shape Rule Creation With Modular Design: Minimizing the Cost of Using Shape Grammars

Shape grammars provide the means to represent the physical embodiment of a class of products in a set of generative rules. Once developed, the shape grammar can be used to generate new forms through automated synthesis or interaction by one or more designers. However, a fundamental shortcoming of this rule-based system is that creating the shape rules is time consuming and imprecise. The traditional approach to create a set of rules from an existing set of products was an ad hoc process of generalizing form, identifying feature options, and classifying logical subdivisions of the complete product geometry. This paper proposes a formal method of shape grammar creation that is aligned with well-known design methodologies and tools in order to enable the creation of a shape grammar during the product development process. The established methodologies for creating functional models and modular products provide many of the requisite steps for creating a shape grammar and provide a skeleton onto which a rule creation approach can be mapped.