Head tracking off-the-shelf solutions

So had a quick look at how to track the head position, just to see what is out there. Some quick findings:

Through face tracking:
Besides the theta/phi that helps present the image from the right angle, we can probably find out the R from the size of the face. Not trivial, will have to see how the effect works out.

1. Of course, we can use OpenCV and all the stuff presented in this blog (only for the position, not so much for rotation).
2. FaceTracknoIR Open source face tracking for Windows. It tracks rotation too...

With markers in the head: Either passive (reflective) or active (LED as light source):

Tutorials:

1. This guy talks too much too but the slides he shows makes everything funnier...
2. I feel this guy talks too much.

Solutions: 

1. FreeTrack (software)
2. OpenTrack (software)
3. LinuxTrack (software)
4. TrackIR (both software and hardware, ~$150)
5. Sony Playstation Move (I include here as it is cheaper than the Vive or Occulus systems...) and the Playstation Camera. Probably these would give you anything beyond position.
6. TrackHat buy the hardware, use the free software (spin from OpenTrack).
7. DIY hardware Mostly about the mechanical part... The electronics is basic if you know anything about it (the LEDs are just DC, not pulsed or anything fancy...)
8. These guys did something very similar to what I had in mind (kind of a virtual window). It was probably inspired in both cases on the great and open job of Johnny Chung Lee

Comparison of both methods (not a good one...)