3D Visualization Moves Forward

Chris writes "Showing for the first time at the Society for Information Display (SID) conference in Boston was a three-dimensional display with 100 million volume pixels or "voxels". The Perspecta is a hardware and software combination that projects 3D images inside a 500 mm transparent spherical dome. Images 250 mm in diameter can be seen from a full 360 degrees without goggles, allowing the viewer to walk around the image. It can be used to visualize protein structures and to plan surgical and radiation treatment by locating the exact position of a tumour on an x-ray or mammogram. It could also be used in air traffic control, prototype designing and security scanning of luggage. Perspecta uses Texas Instruments' digital light processor technology and a spinning projection screen, which sweeps the sphere." We've done some previous stories about this globe from Actuality Systems. The trend seems to be toward simulating 3D with high-resolution flat screens, though.

Comments

Sweeet

[ZaneMcAuley]

Now if only they can get it larger than a snow globe.

Another use...

[Dick Click]

It can also be used to show to a group of people the design flaw in the Death Star.

Aaaaaand, why bother.

[Bowie J. Poag]

Ok, its cool and all.. yeah, being able to project something volumetrically, but is it really _useful_ ? I fail to see how paying $20,000 for a bleeding edge "display sphere" makes more sense than rendering something in stereo, and crossing your eyes, which most visualization packages are capable of doing nowadays anyway.

Where I used to work, we had a number of visualization packages that allowed researchers to view molecules/proteins/DNA sequences in stereo. It was routine, and required no specialized hardware.. You just render two views of the same object, side by side on the screen, with one view taken slightly from the left or to the right of the other. You can manipulate them in realtime, in stereo. Doesnt require glasses.. Just have to cross your eyes. Hell, go visit my site, i've got a couple stereoscopic wallpapers up, and theres nothing stopping me from producing stereoscopic 3D animation in Blender.

:)
Cheers,

Re:Aaaaaand, why bother.

[Riskable]

Ahh, "cross your eyes". Therein lies the problem. You see, there are millions of people all over the world that don't see perfectly out of both eyes. I am one of these people (legally blind in one eye). To us, steroescopic images like the ones you describe will never be more than a blurred picture or static on the screen.

Also, the angle of view on stereoscopic images is usually very limited. Technologies such as this get around that problem by projecting the image onto a curved surface which provides for more of a "true" 3d-look.

The real benefit of technolgy such as this is that we're one step closer to the 3D "JAWS" shark that Marty McFly encounters in Back To The Future 2 =)

Re:Aaaaaand, why bother.

[sab39]

There are only two cues the human brain has to perceive 3 dimensions. One is the relative size of an object, assuming you have some idea how big it should appear at a given distance--focusing your vision is a part of this aspect as well.

The other is the slight difference in image perceived by each eye--called retinal disparity.

Uh, no. There's (at least) one other:

The way the view you're seeing changes as you move your head from side to side and/or up and down.

I'm guessing, but I'd be surprised if this wasn't the reason why most basketball players seem to deliberately bend at the knee (moving their head up and down) before shooting a free throw. Stereoscopic vision doesn't help you perceive how far away a horizontal line is.

For people blind in one eye, I imagine that moving the head becomes much more important as a depth cue. And this system provides that, where stereo images don't.

Re:Aaaaaand, why bother.

[Wraithlyn]

Reading your comment made me wonder if when they were developing CRTs for computer displays, somebody said: "Aaaaaand, why bother developing this in the first place, when we can just display computer output on a line printer, without using any specialized hardware? I fail to see how spending $20,000 for a bleeding edge 'display screen' makes more sense than outputting to paper, which most packages are capable of doing nowadays anyway."

I'm sorry, but I can't help but view this type of argument as anything other than anti-progressive and monumentally shortsighted. I for one (and I know I'm not alone) have never found the "cross-eyed" technique comfortable or intuitive, and even when it works, the resulting depth perception is nowhere near as good as looking at a real object. A true volumetric 3d display would drastically improve the user visualization experience. You want surgeons to rely on crossing their eyes to accurately perceive a high resolution model of your brain when performing surgery? Obviously, it's not as economical as using a stereogram, but it also won't cost $20K forever either. Does it "make more sense"??? In the long run, absolutely.

Re:Aaaaaand, why bother.

[vrt3]

However, if you were to cover one eye and look at a 3D object, you get a totally different sense of that object

To be honest, I don't. I get exactly the same sense whether I use one eye or both. Reason is that in most circumstances only one eye at a time is focused. My left eye is short sighted, while my right eye is far sighted. Very strange, and as an effect I'm bad at perceiving depth. Good enough for normal life; I have no problems driving a car, but it makes parking more difficult.

I can see stereographic images, but it's very hard to get both of my eyes focused simultaneously (up to 1 m I can see sharp with both eyes, further away only with my right eye; depends on lighting conditions though, on a sunny day it's clearly better). Looking trough a binocular or stereomicroscope gives me full 3D view, since they allow me to adjust the focus separately for each eye.

3D techniques that rely on both eyes getting a different image won't have much effect for me, unless the screen is in the range where both my eyes can adapt and focus enough. Or maybe I should get glasses.

Used in security scanning of luggage?

[Gannoc]

I read that, and smelled something fishy. That was almost certainly some marketing moron's idea to mention, since I really doubt the company spent years to develop a hugely expensive three dimensional display in order to SCREEN LUGGAGE.

I despise any company that twists the truth to take advantage of people's fears.

Re:The hell with mammograms...

[Nightpaw]

Strangely enough, these aren't mutually exclusive; any holodeck that I use had better be able to model breasts in three dimensions.

Uh hi.. yeah.. perspecta?

[kwashiorkor]

The Fortune Tellers Association of America called. They want their idea back. They're claiming "patent infringement" or some such.

Re:"voxels".

[DataPath]

the term voxel is hardly new. I recall reading about 3d projections and displays and them using the term "voxel" in association with them close to 12 years ago. And it's not any stupider than calling a 3d square a "cube."

Re:Now geeks can share the interest

[gazuga]

Listen, I don't know what kind of guy you are, but I'm a geek and I'm *plenty* interested in breasts. The problem lies in finding someone who will let you be interested in theirs...

Did this about a year ago...

[Uller-RM]

I did a contract coding job similar to this about two years ago - for an exhibit at a tech expo, we rigged up a pair of curved mirrors and a plexiglass semisphere with a hinged hatch. A projector shot a 1024x768 image through the pair of mirrors, producing an image that gave you roughly 270deg FOV horiz and 90deg vertical. Add a joystick and a rudimentary tunnel shooter... :)

My part of it was hacking up the game engine (Virtools' kit) to render from two in-game viewpoints each frame and distorting the image in a third rendering pass so you'd get a correct image on the screen - lots of optimization, since we were rendering at that resolution two years ago when the Geforce2GTS and 1GHz P3s were the height of consumer technology. That, and some other blocks for the scripting language for level transfers and whatnot.

(The engine used to be marketed under the name Nemo, now called just Virtools Dev. Not too impressive graphically by today's standards, but it has the most artist-friendly scripting system I've EVER seen. If they strapped a decent rendering tech onto it and some network code, they'd have an absolutely outstanding project on their hands.)

Re:Did this about a year ago...

[Uller-RM]

After compositing the two camera images in the framebuffer, it did a read from the back buffer into main memory (specifically, into a block in the heap with buffer space above and below to get a power of 2), was uploaded back to the card as a OpenGL texture, and rendered bilinear across a precalculated set of vertices and UV coords (stored in vertex arrays and display lists). If we were running it on a Voodoo, I could have used Glide to do it all on the card, but this was right when they were ditching Glide, and the rendering engine didn't have a Glide plugin :-\

I would have liked to work out an entirely 2D routine for doing it instead of having to do the texturing, but I was under a rather nasty timeframe to do it, and the example code we got from the inventor of the technique took some time to decipher. Why people insist on doing horrible pointer arithmetic instead of [] (which expands to *(x+i) in the preprocessor anyways), I'll never know.

On a Geforce2GTS the fill rate and AGP2x limited us to about 20fps, but on an SGI NT workstation it absolutely FLEW since main memory and video memory were shared. Unfortunately, we had to do 10 kiosks with this, and the budget didn't allow getting an SGI for each one :-\

Totally different technologies

[SeanAhern]

The trend seems to be toward simulating 3D with high-resolution flat screens, though.

These are completely different technologies. The first is an "actual" 3D display. The voxels have a true location in 3D space, for instance. People can view it from any angle with no equipment.

The second appears to be just a large screen. People wear shutter or polarized glasses to send different images to the left and right eyes.

While the second techology is great, especially for high-resolution display to a single person, it really is annoying when used with multiple people with different locations in space.

Since there is only one set (left and right) images on the flat screen, only one viewpoint can be chosen. If a group of people is sufficiently far from the screen, or sufficiently close together in the room, it's fine. But if you let the people wander around the room, you start getting perspective problems that really make collaborative viewing troublesome.

I have a feeling that we will be seeing voxel-based visualization like the one mentioned in this post more and more often. It's just more natural to use.

As someone who is in the field of high-resolution scientific visualization (that's me on the left), I certainly hope that technology will move in this direction.