A room-sensing camera planted on the front of the Vive Pre was the reason the release of Valve and HTC's virtual reality headset was delayed, the companies revealed Tuesday at CES 2016. The Vive VR headset was supposed to beat Oculus VR and Sony to the punch, coming out in the last quarter of last year. A last-minute "breakthrough" required more work on the Vive headset, HTC CEO Cher Wang said last month.