Research into parametric or associative modelling goes back at least as far as Sutherland’s Sketchpad (1963). Research about shape grammars is only slightly younger1, but does not yet enjoy the same success. A persistent challenge to the more widespread use of shape grammars (and generally, rule-based approaches to design) in architectural and urban planning research is the creation of rules and rule sets for application in design contexts, while leaving space for creativity despite the limitations of a rule-based system. A hybrid of associative and rule-based approaches may alleviate this.

While at NUS Architecture, I developed an API and a Grasshopper shape grammar interpreter plug-in (or the "SGI plug-in") using Python and RhinoCommon. The SGI plug-in embedded a rule-based approach within a parametric modelling environment. It built on previous research about shape grammar interpreters 2 3 4 and relied on the SortalGI engine, a computational shape grammar interpreter which takes in geometry and descriptions to generate rules and implement grammars through a graph-based approach.