This is made possible by merging the live stream from a trio of Kinect sensors, which has been specially arranged in an equilateral triangle around himself, allowing it to generate a 3D image of himself in real time. Of course, this is far from perfect, since the 3D image has its fair share of glitches, but it is a good a start as any. Using this video alongside an Oculus Rift, he then managed to generate a first-person image of his own skin in a virtual environment.
Throw in some computer-generated furniture, and Kreylos himself ends up creating a virtual reality which his brain would be fooled into thinking that everything around him is solid and real. It was so real, that his instinct was to avoid the virtual furniture although he could actually walk through them with his VR limbs. Cool, yes?