Output details

Implementation of curved shape grammars

This article introduces and illustrates a general method of implementing shape grammars on curved shapes. Shape grammars support the formalisation of design spaces, and the generation of design alternatives. The paper demonstrates how the results presented in the complementary theoretical paper (Earl output 3) are put into practice for a category of parameterised curved shapes, cubic Bezier curves, widely used in CAD and design practice. It details methods based on the intrinsic descriptions of shapes to perform the key generative operations necessary for shape grammar implementation. For a shape grammar to be useful and applicable in design, the implementation is critical, particularly the mechanisms to recognise subshapes wherever they occur. This is a non-trivial problem for which general methods are not available. Methods based on rectilinear shapes rectilinear approximations (for example McCormack and Cagan work from Carnegie Mellon University published in Environment and Planning B: Planning and Design in 2002) are largely superseded by methods in this paper. As such, the presented results broaden the scope of shape grammar research beyond architecture to design fields, such as product design, where non-rectilinear, organic forms are dominant. This is emphasised in the paper, where implementation mechanisms are verified and validated through illustrative examples, including an elegant new way to conceptualise Celtic knotwork designs. Follow on work has explored user effective interfaces for shape generation and design synthesis, particularly the role of vision and visualisation in design. This has been the subject of follow on research on ‘Design Synthesis and Shape Generation’ (AHRC/EPSCR Designing for the 21st Century programme) and ‘Design with Vision’ (Leverhulme).