Stereoscopic multi-user systems provide multiple users with individual views of a virtual environment. We developed a new projection-based stereoscopic display for six users, which employs six customized DLP projectors for fast time-sequential image display in combination with polarization. Our intelligent high-speed shutter glasses can be programmed from the application to adapt to the situation. For instance, it does this by staying open if users do not look at the projection screen or switch to a VIP high brightness mode if less than six users use the system. Each user is tracked and can move freely in front of the display while perceiving perspectively correct views of the virtual environment. Navigating a group of six users through a virtual world leads to situations in which the group will not fit through spatial constrictions. Our augmented group navigation techniques ameliorate this situation by fading out obstacles or by slightly redirecting individual users along a collision-free path. While redirection goes mostly unnoticed, both techniques temporarily give up the notion of a consistent shared space. Our user study confirms that users generally prefer this trade-off over naïve approaches.

Engineering systems plays a central role in the development of successful Virtual Reality (VR) and Augmented Reality (AR) applications. Increasing computational resources are utilized to build increasingly complex artificial environments and extensive Human-Computer Interaction (HCI) systems. These types of Realtime Interactive Systems (RIS) establish a closed HCI loop. They are characterized as systems continuously analyzing users' input while concurrently synthesizing appropriate output for several of the human senses in real-time.