Abstract: The present invention relates to a projection system especially intended for projecting three-dimensional representations on a viewing device (8, 12), where the representations submitted to the watcher's eye are put in relation with the respective point where the watcher stands (6,7), to whom sensors are allocated for locating his or her relative position, so that he or she sees on the viewing device an image virtually represented in space in relation to his or her position. In order to allow for the various three-dimensional representations to be viewed by many watchers on the same viewing device, the system projects several image representations simultaneously, each corresponding to the watcher's relative position. Each watcher is allocated image separating apparatus which enable his or her access to image representations corresponding to the place where he or she stands.