A Procedural Modeling Grammar for Virtual Urban Environment Creation

The creation of virtual urban environments, corresponding to realworld settings, has become a very frequent subject of content development for Virtual Reality Systems, serving multiple activities such as urban planning, virtual tourism and education, among others. Their extensive and complex nature, however, makes their conception very expensive and time-consuming, which has led many researchers for the look of semi-automatic methods for their creation. This paper describes the PG3D Grammar, a specification for modeling guidelines, which aims to provide a powerful control over the procedural modeling processes based on GIS data. This is achieved by allowing the integration of real-world data source queries and by providing management facilities to handle their large number, dimension, format and level of detail. The grammar can then be integrated into a procedural modeling tool for generating very large virtual real-world urban environments without further need for human intervention.