Résumé: In this article we present a prototype system for the computer support of collaborative urban planning. The system is based on the Virtual Table, a collaborative work environment with a rear-projection table. There are two main contributions in our work, a tangible interaction interface for the Virtual Table, and a 3D-GIS linked to it. We present a new approach to tangible interaction with rear-projection tables, that uses physical, ` active a pieces which are easy to build and to track. A set of di!erent pieces with di!erent actions attached to them can be tracked simultaneously, facilitating group interaction with the planning and decision support system. Active pieces are used to interact with a 3D-GIS supporting a three-dimensional query space in addition to photorealistic visualization.

Langue: Anglais