“Microsoft HoloLens is the first self-contained, holographic computer, enabling you to engage with your digital content and interact with holograms in the world around you.” However, I found it to have limited view area. The gestures worked well to control the virtual components.
https://www.microsoft.com/en-us/hololens

This is a new way again to interact as the actions are not into any controller or system at all, they are in mid air. Air gestures have been around for a while but seem to only be catching on recently with the latest smartphones advertising using air gestures to do things such as go through photos etc..

instruments have also made use of these actions such as the Infra-Red Harp. http://www.thenaturalistsnotebook.com/our-blog/a-harp-with-no-strings