This paper presents a new architecture for simulating virtual humans in com
plex urban environments. The approach is based on the integration of six mo
dules. Four key modules are used in older to manage environmental data, sim
ulate human crowds, control intel actions between virtual humans and object
s, and generate tasks based on a rule-based behavior al model. The communic
ation between these modules is made through a client/server system. Finally
, all low-level virtual human actions are delegated to a single motion and
behavioral control module. Our architecture combines various human and obje
ct simulation aspects, based on the coherent extraction and classification
of information from a virtual city database. This architecture is discussed
in this paper, together with a detailed case study example.