Expeditious Modelling of Virtual Urban Environments with Geospatial L‐systems

Abstract

Abstract L‐systems have been used in Computer Graphics, namely for modelling plants, as well as in a few experiments to model urban environments. However, the lack of geospatial awareness is a limitation and in spite of some developments like open L‐systems, that introduced the ability to communicate with the environment, there was a need for more flexibility. This paper presents Geospatial L‐systems, a new extension of L‐systems that incorporates geospatial awareness, and shows an application in the area of expeditious modelling of urban environments. A modelling system, named XL3D, generates virtual urban environments automatically from a XML based document that contains a modelling specification and accesses data sources in an interoperable way. The integration of geospatial L‐systems in this modelling system has increased the potential for automation and the potential to generate virtual urban environments with a higher level of detail and visual fidelity, with a lower level of complexity of the modelling processes. These facts are shown in a case study where a virtual urban environment, taken from an area in the Porto downtown, is generated by this solution.