Tracking a head mounted display in a room sized environment with head mounted cameras

This paper presents our e orts to accurately track a Head Mounted Display HMD in a large environment We review our current benchtop prototype introduced in WCF then describe our plans for building the full scale system Both systems use an inside out optical tracking scheme where lateral e ect photodiodes mounted on the user s helmet view ashing infrared beacons placed in the environment Church s method uses the measured D image positions and the known D beacon locations to recover the D position and orientation of the helmet in real time We discuss the implementation and performance of the benchtop prototype The full scale system design includes ceiling panels that hold the infrared beacons and a new sensor arrangement of two photodiodes with holographic lenses In the full scale system the user can walk almost anywhere under the grid of ceiling panels making the working volume nearly as large as the room