Simultaneous mapping and redirected walking for ad hoc free walking in virtual environments

Providing real walking in virtual environments remains a challenge because of space, setup, and tracking system requirements. With the help of redirected walking (RDW), natural and unconstrained walking in virtual environments has become possible - without using mechanical locomotion devices - by manipulating the user's real world trajectory such that he remains within the boundaries of the walkable space. Nevertheless, typical home or office environments do not provide sufficient space or a suitable room which is free of obstacles. This paper presents an approach that combines RDW with a low-cost and user-worn tracking approach based on simultaneous localization and mapping (SLAM). I.e. learning the environment with the walkable area, tracking the user's viewpoint, and RDW is done on the fly without any prior setup, without preparing a room, and without setting up a tracking system. This allows ad hoc free walking in virtual environments even within dynamic and cluttered physical rooms, where the walkable area is of arbitrary shape. Furthermore, by combining SLAM and a planning RDW controller, this approach has the potential to provide the best free walking experience for any given physical environment.