Glasses-free 3D has taken several forms, but most have a critical flaw -- viewers have to stand in predefined locations to get the effect. That just won't do, so Microsoft's prototyped a new approach, and it's one of the wildest we've seen. Taking a cue from Project N... we mean Kinect, cameras track the face while a special wedge-shaped lens traps bouncing light, and after the beams have reached a "critical angle," it exits towards the viewers eyes, aimed by programmable LEDs at the bottom of the screen. Since the system can beam a pair of simultaneous images to two different places, the obvious use is stereoscopic 3D, but researchers found they could also send different images to different viewers, as a sort of privacy screen. If that sounds far fetched, you're not alone -- but you'll find a video proof-of-concept at the more coverage link.