Abstract
This article describes the first implementation of a new SAR, spatial augmented reality, equipped here with a IPM, interactive projection mapping. It presents and analyses it as a new configuration of CSCW, Computer-Supported Cooperative Work. It reveals its success (support encouraging the collective understanding of complex shapes) but also the precautions and limits of this system of graphic interactive projection on a 3D model (delicate calibration, cognitive overload of utilization). It gives details of the adjustments to the status of co-participants (more passive), the status of work space (becoming an extended we-space) and the status of the common artifact (unmovable but polymorphic).