CuBrush is a room-scale experiment with Oculus Rift that lets you walk around and draw with cubes within a 3D environment. It's designed to work with a single tracking camera and an Xbox controller, so no motion controllers are required.
It has its own chaperone-style boundary system - Unity doesn't track when the headset is taken off so boundaries need to be set while wearing the headset or by holding the headset and covering the head sensor.
Update notes