To much dancing queen
Detect the movement of the user with a camera. Examples are TrackIR for head tracking or Kinect for body tracking.
Reference
Kinect 2 Hands On Labs - 2015
Viability of Using Markerless Motion Capture : In the Creation of Animations for Computer Games - 2014
Real-time filtering for human pose estimationusing multiple Kinects - 2014
A 3D OBJECT SCANNER : An approach using Microsoft Kinect. - 2013
Kinect 3D Mapping - 2012
A Motion Capture System Based on Natural Interaction Devices - 2012
Links