Multilevel modelling of virtual urban environments for behavioural animation

The Praxitele project is responsible for the design of a new kind of transportation in an urban environment, which consists of a fleet of electric public cars. These public cars are capable of autonomous motion on given journeys between stations. The realization of such a project requires experimentations with the behaviour of autonomous vehicles in the urban environment. Because of the danger connected with these kinds of experiments in a real site, it,vas necessary to design a virtual urban environment in which simulations could be done. Reproducing the real traffic of a city, as completely as possible, implies the simulation of autonomous entities like living beings. Such entities are able to perceive their environment, to communicate with other creatures and to execute some actions either on themselves or on their environment. Databases for virtual environments are often confined to the geometric level, when they must also contain physical, topological and semantic information. Accordingly in this paper we present VUEMS, a Virtual Urban Environment Modelling System which is designed to manage different levels of representation by assembling geometric, topological and semantic data in the field of traffic simulation. From real world data (when available), we construct a Model of the Virtual Urban Environment, integrating all the information needed to describe the realistic behaviour of car drivers