Longstanding VR tech firm WorldViz has what it calls a "warehouse-scale" motion tracking system for virtual reality experiences, and next month that tech will be accessible to game developers via new Unreal Engine 4 and Unity 5 plugins.
What this means, for most VR devs, is relatively little: WorldViz's Preicision Position Tracking system has a starting price of $15k, and goes up from there depending on how many cameras and sensors you need to adequately cover a large space.
However, it's still an interesting opportunity to consider what sort of games and other experiences could be developed with PPT tech for the headsets known to support Unity and Unreal. That encompasses everything from Samsung's Gear VR to the PlayStation VR and the HTC Vive, which is only designed to track movement in a 15 x 15 meter space via its Lighthouse room-scale tracking system.
WorldViz, by comparison, claims its PPT system can simultaneously track up to ten people or things, in spaces of 50 x 50 meters or larger, with "sub-millimeter accuracy" using affixable sensors and hand-tracking wands. While WorldViz's VR tech has a low profile in the game industry, it has long been used by universities, VR research groups and government institutions.