Shape Grammars for Architectural Heritage

Shape grammars have been introduced in architectural theory some decades ago. They have been applied to architectural construction methods (e.g. Chinese traditional wooden buildings) or for analyzing the design patterns of well-known architects (e.g. Palladio, Frank Lloyd-Wright). These examples demonstrated that complex geometrical shapes could be generated by a set of replacement rules out of a start symbol, usually a simple geometric shape. With the advent of powerful tools like the CityEngine an interesting field for practical applications of these grammars arose opening a whole range of new possibilities for architectural heritage. On the one hand, a description of ancient building principles in the formalized way of a shape grammar can aid the understanding and preservation of cultural heritage. With the possibility to actually construct digital 3D models out of shape grammars, they became even more interesting. Furthermore, this approach allows for a large scale creation of 3D models of entire settlements and cities. On the other hand, shape grammars allow for structured approaches to virtual 3D reconstruction as has been demonstrated for e.g. Mayan or Roman architecture. Besides that, the possibility to specify parameterized variations of the models proves to be an extremely helpful feature. In this paper we reconsider shape grammars in architecture and examine influences onto procedural modelling. Then we argue for state-of-the-art tools like the CityEngine that apply shape grammars and procedural modelling in architectural contexts and exemplify their power and potential by reconstructing traditional Balinese settlements.