In this paper we present a user-centered design approach to the development of a Virtual Environment (VE), by utilizing an iterative, user-informed process throughout the entire design and development cycle. A preliminary survey was first undertaken with end users, that is, architects, chief engineers, and decision makers of a real-world architectural and urban planning project, followed by a study of the traditional workflow employed. We then determined the elements required to make the VE useful in the real-world setting, choosing appropriate graphical and auditory techniques to develop audiovisual VEs with a high level of realism. Our user-centered design approach guided the development of an appropriate interface and an evaluation methodology to test the overall usability of the system. The VE was evaluated both in the laboratory and, most importantly, in the users' natural work environments. In this study we present the choices we made as part of the design and evaluation methodologies employed, which successfully combined research goals with those of a real-world project.

Among other results, this evaluation suggests that involving users and designers from the beginning improves the effectiveness of the VE in the context of the real world urban planning project. Furthermore, it demonstrates that appropriate levels of realism, in particular spatialized 3D sound, high-detail vegetation, and shadows, as well as the presence of rendered crowds, are significant for the design process and for communicating about designs; they enable better appreciation of overall ambience of the VE, perception of space and physical objects, as well as the sense of scale. We believe this study is of interest to VE researchers, designers, and practitioners, as well as professionals interested in using VR in their workplace.