The LeapMotion is quite nice to use with WebGL / three.js.
This is definitely a cool hack, but it does not involve 3-dimensional projection. This is a 2D image cast on to a 2D projection plane with no stereoscopic effect. That makes the term "3D hologram" a misnomer at best, and a gross misrepresentation at worst.
Because of this mislabeling, we're all sitting around talking about the inaccuracy of the title, rather than the fun part. That's the fault of the person who titled the article, not the person pointing it out.
This demo is neat. No question about it. I like when people play with ideas like this.
The demo isn't any more a hologram or 3D than if I took four LCD's, arranged them as the sides of a cube and turned down the lights. Other than not seeing through the LCD's, the images would be the same.
Again, as the person you are accusing of being pedantic said, this is no hologram and it isn't 3D in almost any imaginable way.
Notice how he moves from angle to angle quickly with the camera? That's because there are no volumetrics here. It's just a flat 2D image effectively seen through a 45 degree partial mirror.
It's a 2D image that appears to float in space. And it's cool.
Many, many years ago I thought about the idea of installing a screen spinning or translating (harder mechanically, easier imaging) at high speed in a vacuum chamber with transparent walls and then using lasers to project slices of a true 3D scene onto it. Challenging, but it would be really interesting to see how something like that works out.
I've been writing about it at http://leaphacking.com
Leap has announced that the devices will be available to the public on May 13.
It's a nice compliment to the XBox Kinect, too.
Gesture recognition has been added so I need to spend a bit of time with that today.
There are a few companies working on this at once; I think it's definitely something to keep an eye on. It seems like a natural evolution of webcams.
As long as the user lines up with the center line properly, the image would be both "ghostly" as here and also stereo 3D.
As cool as this demonstration is, it's using a 19th-century technique -- "Pepper's Ghost" -- and cannot correctly be called holographic.
Here's work out of MIT depicting the true state-of-the-art in real-time electroholography: http://web.mit.edu/newsoffice/2011/video-holography-0124.htm....
But this isn't even stereoscopic. This is just a 2D image reflected on a piece of glass.
It's essentially a way to "record" light the same way you can record sound in grooves or magnetic tape.
I'm curious what it looks like viewed from one of the edges - I can't picture it being seamless?