Procedural Design of Urban Open Spaces

This paper presents a novel approach for the automatic creation of vegetation scenarios in real or virtual 3D cities in order to simplify the complex design process and time consuming modeling tasks in urban landscape planning. We introduce shape grammars as a practical tool for the rule-based generation of urban open spaces. The automatically generated designs can be used for pre-visualization, master planning, guided design variation and digital content creation in general (e.g. for the entertainment industry). In a first step, we extend the CGA shape grammar by Muller et al. (2006) with urban planning operations. In a second step, we employ the possibilities of shape grammars to encode design patterns (Alexander et al., 1977). Therefore, we propose several examples of design patterns allowing for an intuitive high-level placement of objects common in urban open spaces (e.g. plants). Furthermore, arbitrary interactions between distinct instances of the vegetation and the urban environment can be encoded. With the resulting system, the designer can efficiently vegetate landscape and city parks, alleys, gardens, patios and even single buildings by applying the corresponding shape grammar rules. Our results demonstrate the procedural design process on two practical example scenarios, each one covering a different scale and different contexts of planning. The first example illustrates a derivation of the Garden of Versailles and the second example describes the usage of high-level rule sets to generate a suburbia model.