[dmos62]

There's been some activity in the gaming community for DIY solutions to track head movement. Or really any accessible way to get in-game head/camera rotation and/or tilting independent of what the mouse or keyboard is doing.

The simplest one is webcam face feed interpretation. It's also the least liked, because it's CPU/GPU intensive.

The most energy efficient one is based on small devices than measure distance between each other via radio signals or something similar. You put one of them on your head. It has the drawback of having to buy the (cheap) devices.

A middle-ground, which is probably the most popular solution, is a funny looking cardboard cutout with IR reflectors or lights that you put on a hat or headphones. Then you use a webcam feed, but its interpretation is much simpler, because the points to track are easily distinguishable.

All the webcam methods have a significant drawback that they require illumination. You either need lights on your head, or your face has to be brightly illuminated (visible light or IR). A light in my face is the last thing I want personally.