SAGE: A tool for intuitive design of shape grammars

Abstract

Shape Grammars are rule-based systems for generating spatial compositions, offering a formal and flexible approach to design generation. However, existing tools often require advanced knowledge of formal systems and programming, limiting their accessibility to a broader audience. This paper presents the tool SAGE, which stands for ShApe Grammar assisted Environment, designed to make Shape Grammars more intuitive and approachable to users of all backgrounds. SAGE enables users to create shapes, define transformation rules, and assemble procedural grammars through an integrated visual programming interface. Developed with an iterative prototyping approach, it bridges the gap between formal generative systems and user-friendly interaction models. An evaluation based on user testing and user feedback revealed key usability challenges and informed successive interface refinements. The results suggest that the proposed tool successfully lowers the entry barrier to Shape Grammars and offers a promising foundation for future educational and professional applications.