Lighthouse

Lighthouse is a positional tracking system developed by Valve for SteamVR. It accurately tracks the position and orientation of the user's head-mounted Display and controllers in real time. Lighthouse enables the users to move anywhere and re-orient themselves in any position within the range of the SteamVR Base Stations. It is a key technology that enables SteamVR to create the first holodeck or full-room experience in Virtual Reality.
Valve plans to make Lighthouse freely available to all hardware manufactures.
How It Works
Central to the Lighthouse technology are the Base Stations, small rectangular objects placed in the room. They serve as reference points for any positionally tracked devices such as the HMDs and controllers. Base Stations perform this function by flooding the room with a non-visible light