What happens when you combine (no pun intended) the easily modified Source engine with a penchant for homebrew tech? This VR tracking mod for Half-Life 2, designed to let players step into the orange HEV suit of Gordon Freeman.

"I've added full head tracking and weapon tracking to Half-Life 2 in preparation for the Oculus Rift dev kit launch," writes the creator Nathan Andrews. "Once the official rift APIs are available I'll integrate them, giving people ~70 hours of content (this also works for episode 1 & 2, the Lost Coast and tons of user generated maps, etc) that they can use to test out their Rift."

In lieu of the dev kits, the mod is being tested on a somewhat less refined version of the tech. "This video shows a handful of scenes of me using the head and weapon tracking using two hillcrest trackers (the same ones that John Carmack used for the Doom 3 BFG demos of the early oculus rift prototype). This video was made using my modified HMZ-T1 but others have played it on DIY rifts with the Vireio stereo/warp drivers."

Those expecting delivery of a Rift - or those who've somehow gaffa-taped together a similar set-up - can download the mod from here .

This does open the possibility of a Portal Oculus Rift mod, although that will almost definitely make people sick.

Thanks, CVG .