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Camera based Relative Motion Tracking for Hand-held Virtual Reality

In this paper, we present a vision based relative tracking for use in hand-held virtual reality systems. Hand-held virtual reality system refers a virtual reality system that is self contained with a computer and multimodal sensors (e.g. 3D tracking, voice recognition, motion sensing, etc.) and feedback (e.g. graphic, sound, and tactile display) all hold-able in one hand. Relative tracking refers to an approximate tracking of the hand-held VR system (thus, the user’s hand or body) in relation to the environment. Such relative tracking of the user’s body can be used for various interaction tasks and induce a whole body experience in contrast to simply using the “arrow” buttons. The vision based relative tracker uses one camera (and without any environment markers or landmarks) to first select and capture distinct features from the incoming images and calculates the approximate directions and amounts of their motion, including translation, rotation and zoom. This in turn can be used to infer the motion of the user. Using such a tracker, the user can, for instance, navigate through a virtual environment seen through the hand-held VR display and select objects through physical metaphors. We also compare such body based interface to the usual button-based one in terms of performance and preference through a usability study. CR