[Philip Lelyveld comment: the video demonstrates creating a 3D sphere floating in space using 10 projectors and fog.  This is a weak but interesting proof-of-concept demo.  The last 2 minutes of the 5 minute video is a political statement and consulting pitch, and can be skipped.)

[ThinQ]

Marc Ressl, a professor at the Buenos Aires institute of technology, has shown off a new sort of 3D projection that he’s created, using what he calls a “volumetric projector”, Wired reports.

By utilising many projectors – in this prototype example he uses 10 – a 3D object can be created within a bank of smoke, though he claims that for a truly accurate 3D to float freely, there would need to be somewhere in the number of 100 projectors. He explains in the video that due to the lower number of projectors used, that the sphere generated was unfortunately a low contrast and resolution, but that it provided a good proof of concept.

See the full story and the video here: http://www.thinq.co.uk/2011/11/7/volumetric-projector-does-floating-3d/

Also see the video here: http://www.youtube.com/watch?feature=player_embedded&v=ijOK_hb18kE