In Virtual Reality a user immerges into a virtual world using special display devices. One currently popular such device are Head Mounted Displays, where a user looks around in a virtual world by turning his head or walking around while wearing the display. In augmented reality, the real environment is augmented with virtual objects. Again, this requires special display devices that overlay the real world with virtual content (e.g. AR glasses such as the Microsoft Hololens), or by using projectors that display virtual content onto their surrounding.