>>392538158
There's the 360 Kinect and the Xbox One kinect. The later works 'better' but requires an expensive adapter. It's supposedly possible to solder something to bypass but when I tried it exploded, so I don't know if I just got trolled.

It does only track your legs. Hip movement doesn't work at all. You have to face it exactly, so you can no longer turn in real life at all. It has a lot of performance overhead, especially if you use more than one to get a wider tracking range. The 'tracking' consists of: if you move your leg, your leg will move in a different way about a second later. It feels like Wii controls rather than VR tracking.