A framework for a design tool based on shape grammars is presented
as an effective means for supporting the early stages of design.
The framework uses a shape grammar interpreter to implement
parametric shape grammars, allowing the grammar to be used
interactively by a designer or optimization routine. A shape
grammar to design inner hood panels of vehicles is introduced
as an example of a parametric engineering shape grammar, and
it is used with the framework to create standard and novel designs
made possible by rules that take advantage of shape emergence.