Mesh Compression for 3D Graphics

IanDanforth writes "A new algorithm that uses successive approximations of detailed models to get significant compression has been revealed by researchers at The University of Southern California. Just as MP3s remove high frequencies we can't hear, this algorithm removes the extra triangles in flat or near flat surfaces that we can't see. Experts in the field are giving this work high praise and imply that is will be immediately applicable to 3D modeling in games, movies, CAD and more."

Re:Patented?

[mi]

MP3 is patented. Chilling [chillingeffects.org] or not, just about everyone is using it.

Impressive.

[autopr0n]

I'm surprised no one's done this before, actually. Good texture maps, and especially bump maps can alleviate the need for a lot of triangles. I wonder if this compression routine takes those things into account. It would be great if you could pass in a detailed mesh, and get a simple mesh + texture + bump map back out.

Re:Useful, but over stated...

[yasmar]

There is a lot of work on mesh simplification and compression happening right now because there _is_ a real need for it. Meshes that are modeled by hand may not benifit from it, but many many mesh datasets are being produced by laser range scaners or isosurface extraction of volume data (from some kind of medical imager such as mri say). These meshes are often messy and generally have far more polygons than they need.

Is this maybe a little hyped?

[Shanep]

I've been using 3D Studio for about 12 years. I can't remember when this type of triangle reduction feature came in, but 3DS had it.

It would basically reduce the number of trianges more where they together made flatish surfaces and practically not touch the triangles that made up significant details.

"Mathieu Desbrun, assistant professor of computer science at the USC Viterbi School of Engineering says that digital sound, pictures and video are relatively easy to compress today but that the complex files of 3-D objects present a much greater challenge."

What!? How hard is it to remove triangles based on the direction that they face!?

"His "Variational Shape Approximation" scheme created with two collaborators produces simplified but highly accurate "meshes" representing 3-D shapes. The meshes are orders of magnitude smaller than those produced by existing ways of handling such files but remain completely compatible with all widely used methods to display and use the information."

This is really hyped. This is not compression in the sense of MP3, where you have to decode it. It's just replacing lots of small trianges that make up a flatish surface, with fewer large triangles or polygons. Big deal!

"The proxy representation, once refined, is then reconverted into a now-optimized mesh -- but not necessarily a mesh of triangles. The technique turns them instead into an assortment of polygons -- some triangles, but also four, five, six or more sided figures that more efficiently represent the shape"

Could this be a cop out? Since it could be difficult to replace some triangle groups with a larger triangle without changing the overall shape?

Polygon's are traditionally reduced to triangles for speed benefits! So why not go that little extra?

"This is not a hack," says another expert, in the field GÈrard Medioni, professor of computer science and chair of the department at the Viterbi School, using the term for a makeshift, unsystematic improvisation. "It has a strong formal basis. You can make up extreme cases that will trick it, but for ordinary shapes, it works remarkably well."

Cool, Shrek 3 will be nothing but primitives! Move along, nothing to see here...

the use of this technology...

[davenz]

is probably not going to be seen by the end user in games or movies or otherwise, as has been noted 3d models are allready as low poly as they can be. The only use that comes to mind is in the area of scanning real models into computers which outputs huge files and many many poly's, this is where an algorithym like this would be very useful to get a model that can be used without being overtaxing on system resources.

Re:This isn't new?

[WasterDave]

Ok. So, your post summarises exactly what is wrong with Slashdot that never used to be wrong with Slashdot.

We have hoardes and hoardes of "lighwave/maya/povray/myarse has had this for years" posts, some completely wrong understandings of MP3's, a few dozen soviet russia's and profit! posts then this.

Modded +5, like everything else, but actually *genuinely* insightful and written with a confidence and succintness that comes from knowing WTF you are talking about.

Jesus. Problem with Slashdot is that there's GOLD in them hills but it's a bastard to find.

Dave

Re:slow connections

[LostCluster]

You can watch multiple mp4 video/audio streams at this speed - so why not 1 3d model?

Because we're all still using 2D cameras and monitors... and that's the real hold-up in 3D content production. Things like QuickTime VR have been around for years, but haven't really caught on because they're not easy to make content with and the results are not exactly stunning sometimes.

jesus,i never knew there were so many idiots on /.

[Anonymous Coward]

If you people don't know what you're talking about then why not just not say anything ? 90% of the posts in this thread are from idiots who know a tiny amount about the domain, and feel they can flaunt and strut their embarrassing morsel of knowledge in front of the community. grow up.
No one is claiming that there haven't been algorithms to do this job before - there are quite a few - but IT'S FUCKING HARD. Reducing the complexity of shapes while retaining their identity is a very tough problem - just because 3D studio has the ability to simplify geometry doesn't mean it does a particularly good job of it. Most games houses for instance can't rely on automatic simplification of models and have to employ people to hand craft low poly models. Newer techniques such as normal mapping are making this more automated, but even then there is a lot of scope for improvement - it's exactly for those kinds of uses that this algorithm (if it's as good as they say) will be the most useful.
As for the guy who offered his hilarious description of MP3 encoding as "encoding the differences between one frame and the next", perhaps now might be a good time to crawl under a rock.

Re:Proliferation of 3D Content on the Web?

[Lord Kano]

The real reason 3D content hasn't taken off is that it frankly isn't very useful for every-day browsing.

Just wait until the porno industry gets involved. Imagine being able to freeze frame and get Matrix-like fly arounds of the money shot.

Seriously, my first jpgs and gifs were of porno. Not schematics, or technical info. But big bouncing boobies. I'd be willing to bet that most of you who go back to the 1980s or before had a similar experience. Or how about streaming video? Porno and Mac World expos were the first streaming videos that I ever heard about. If this type of thing is going to take off it'll be because of smut. Sad isn't it?

LK

Re:Proliferation of 3D Content on the Web?

[rsmith-mac]

Sad? How is it sad? As far as I'm concerned, the porno industry is the "perfect" industry from a geek perspective. They are technological innovators that are always willing to try something new and are always on the bleeding edge of technology, they believe in free speech instead of trying to squish it, and they, unlike their **AA counterparts, aren't trying to sue the pants off of the online world, or run to Congress whining.

It's not a sad thing, it's a great thing. The fact that the content is what it is, is unimportant; what counts is that there's an industry out there that's willing to "do things right" the first time, rather than be dragged kicking and screaming.

Uh

[bonch]

they believe in free speech instead of trying to squish it, and they, unlike their **AA counterparts, aren't trying to sue the pants off of the online world, or run to Congress whining.

Nice random MPAA/RIAA dig there (is it all Slashdotters think about anymore that they have to interject it at every opportunity?), but the fact is that there have been several articles in the past five years about how the porn industry is worried about P2P because it pirates their material. Ever done a search on eMule to see how much porn is out there ripped from the subscription sites?

The porn industry doesn't run to Congress because Congress isn't going to take a porn industry seriously! Painting them as some sort of free speech golden defenders is hilarious--they're a sleazy, money-grubbing business like any other (and they like to buy ad space through horrible spyware delivers like CoolWebSearch).

Re:Proliferation of 3D Content on the Web?

[Rostin]

Right. I already know how this will be responded to, but I'm going to say it anyway.

Most of the girls you see in porn movies and pictures aren't there because they really enjoy doing porn.

They are probably there because at first they needed money (porn pays well), and started out by doing some non-nude or semi-nude pictures, then they just got tangled up in all of it.

I don't have statistics or anyting, but honestly, do you think a lot of women just decide one day that they want to receive anal sex from one stranger while giving a blow job to another? Maybe in your fantasies, but I think we both know that in real life, very few women like that exist, and if they do, they probably need some kind of help.

So yeah, notwithstanding the incredible greatness of the porn industry because it's willing to technologically innovate and is a powerful force for free speech (sarcasm), I think it is incredibly sad.