This is an interactive effect entirely made with vvvv. This video has no post-production on it at all, it is 100% generated in realtime.
The idea : if there is someone in front of the controller the spray/ball will transform into the Spectral and you can control it with your Kinect.
Then, if there is nobody, the Spectral will transform back into the spray/ball and move around.
You can download all the source patch here : vvvv.org/contribution/spectral-kinect