Valve also reveals further details about their SteamVR system, elaborating on the reveal of HTC's VR headset and announcing Lighthouse, their codename for a "room scale" tracking system. Here's word:

Valve will show a virtual reality (VR) headset. Developer versions of the headset will be available this spring, and partner HTC will ship their Vive headset to consumers by the end of the year.

Two new technologies are part of the VR release - a room scale tracking system codenamed Lighthouse, and a VR input system. "In order to have a high quality VR experience, you need high resolution, high speed tracking," said Valve's Alan Yates. "Lighthouse gives us the ability to do this for an arbitrary number of targets at a low enough BOM cost that it can be incorporated into TVs, monitors, headsets, input devices, or mobile devices." Valve intends to make Lighthouse freely available to any hardware manufacturers interested in the technology.

"Now that we have Lighthouse, we have an important piece of the puzzle for tackling VR input devices," said Valve's Joe Ludwig. "The work on the Steam Controller gave us the base to build upon, so now we have touch and motion as integrated parts of the PC gaming experience."

"We've been working in VR for years and it was only until we used SteamVR's controllers and experienced the magic of absolute tracking that we were able to make the VR game we always wanted to make," said Alex Schwartz of Owlchemylabs.

VR demos being shown at GDC include work from Bossa Studios, Cloudhead Games, Dovetail Games, Fireproof Studios, Google, Owlchemylabs, Skillman & Hackett, Steel Wool Games, Vertigo Games, and Wevr.