HTC Vive Tracker brings anything into the virtual world
 

Even though Valve offered up its tracking technology and SteamVR APIs for free last year, we've yet to see a proliferation of third-party VR products. That may be about to change, though. At CES, HTC was showing off its latest attempt to entice peripheral purveyors: the Vive Tracker. The new device is essentially a Vive-styled hockey puck with three stubby legs. HTC says you can slap it on any suitable object to track it in VR, in as similar fashion to the touch controllers included with the Vive.

http://techreport.com/news/31265/htc...-virtual-world