Scientists at the Max-Planck-Institut in Germany have created the closest thing we have to a real-life holodeck using a wireless Oculus Rift and multiple cameras distributed inside a 10m by 10m room. Of course, it's still far away from Star Trek, but it works. Watch the video to see how.
Subjects in the lab wear markers and are tracked down to the nearest millimetre using infra-red cameras and markers with the same technology used in cinema for motion capture. The system knows exactly where they are, where they are headed and where they are looking. This takes it well beyond the capabilities of the current Oculus Rift.
The key to the immersive experience is that there are no cables attached to the person, who can wander freely through the room. The only problem right now is that only one person can use it like this -- there's not enough wireless bandwidth to support more than one person.
Despite the large area, it's still a relatively small space compared with many of the simulated virtual environments, so the scientists have to trick people using different techniques.
For instance a person sees in the headset a movement of four feet when in reality it is just two. The same experimentation is being undertaken with angles of turn by subtly rotating the virtual world around the subject. These experiments into what is referred to as redirected walking are looking at where the boundaries and limits lie of plausibility for the user.