Slashdot Mirror
A 3-D Holographic Display
ZonkerWilliam sends along a link to a Wired writeup on a novel 3-D holographic display developed at USC. Be sure to watch the video at the bottom of the page. "The process is not simple but can be defined through a few key concepts: Spinning mirrors, high-speed DLP Projections, and very precise math that figures out the correct axial perspective needed for a 360-degree image (even taking into account a viewer's positioning.)"
From the YouTube page (http://www.youtube.com/watch?v=YKCUGQ-uo8c): "Added: August 31, 2007"
Good to see Slashdot is up to date and timely as always...
For much more detail and higher-res video / images, go to:
http://gl.ict.usc.edu/Research/3DDisplay/
Bah! Its all smoke and mirrors. Well minus the smoke.
In a sense it is. What they have is a projector shining onto a mirror. When the mirror is facing the north, they display the north image. When it is facing south, they display the south image. When it is facing 32 degrees, they display the appropriate image. They divide the horizontal plane into 288 1.25 degree segments and display the appropriate image to each segment. Chances are that your eyes, being in the horizontal plane, will be in two separate segments. They will each receive the image appropriate for the segment they are in. Your brain will merge the two images together to form a 3D image. If you are too far away, your eyes will be in the same segment, and will receive the same image, and the 3D illusion will collapse.
There is also no true vertical paralax with this system. You could move left or right to see behind an object, but you could not move up or down to see behind an object. Yes, the article says that that you can, but that is somewhat misleading. In order to get vertical paralax, they must track the location of the viewer and alter the image accordingly. Everybody viewing the image would see the same vertical aspect of the image. They do have the ability to track multiple viewers' vertical position, so the person to the north could see a different vertical perspective than the person to the south, but two people at close horizontal angles would see the same vertical aspect.
When our name is on the back of your car, we're behind you all the way!
The image in the middle of the article, with two pairs of TIE fighter images side by side appears to actually be two stereoscopic pairs, arranged for cross-eyed viewing.
I didn't find a caption or any other explanation, but give it a try. The video is great at showing how real the object seems from a rotational perspective, but viewing the still-frame of the TIE in 3D really drove it home for me.
If none of that makes any sense, try google's help.