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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."
Wide-spread use of graphics on the web didn't really take off until jpeg and gif compression became common. Will the easy compression of 3D models allow use of 3D content on the web to take off?
Alphanos
So, is this something everyone can use, or will it be patented?
The perfect sig is a lot like silence, only louder
I think this is interesting, but the analogy drawn between MP3s and this 3d-object compression is a bit strained.
The MP3 compression routine revolves around 'frequency masking' much more than it does "remov[ing] high frequencies we can't hear". Most of the work in MP3 is done through 'frequency masking'. That is, imagine a graph of the frequencies being played at any given time- find the high points, then draw sloping lines down to either side of those points. Humans can't hear anything under those lines- they're 'masked' by the nearby strong frequency.
Nothing very much like that goes on in this algorithm. There might be some other mesh-compression-analogous process that goes on in MP3 that's like this, but that ain't it.
Sorry to nitpick, but I figured it's important that
1. MP3 compression is not just simply throwing out high frequencies (a lot of these are actually retained) and
2. This isn't anything analogous to that, anyway.
Looking over my post, I'd have been fine if the submitter had said "Just as MP3s remove frequencies we can't hear, this algorithm removes..." but that's not very descriptive anyway.
RD
Well, if THAT surface was there I bet there was someone to put it there, and (s)he thought that it had some useful function...
;-)
How would you like to fly a plane designed without those thin "thingies" called "wings"?
Paul B.
Man, this has been around for years. I'd bet a decade. Almost all GPSes with mapping features use a 2D variant of this to store less line segment data for roads. 3D systems with multiple levels of detail choose among a number of differently-optimized models to reduce vertex transformation overhead on far-away objects. Where have you guys been?
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I am for cannot waiting able frequency to this have! I too am so greatness compression going to get.
I am ask: can use this games? UT2k4 is good. It is very big game however maybe some for people.
Can this technology fast enough for gaming be?
Read journal when you are not understand
A decade ago, 14.44k modems were top-of-the-line, and expensive, and your provider either billed by the hour or $50/month.
/1mb up, the modem costs $100, with a $100 rebate (so it's free) and the service is still $50/month.
Today you can get a cable modem connection at 5mb down
You can watch multiple mp4 video/audio streams at this speed - so why not 1 3d model?
The actual paper can be dowloaded from here.
-jim
This is a great way to minimize scan data, but it isn't as useful as the article makes it out to be. Most modeled 3d objects are as low resolution as possible. Shrek has as many polygons as he needs to have, to take away some, or swap their location would destroy the model. For instance, I am a Modeler/TD and most animable character models have 5 divisions, or 'loops' around a deformable joint. Any less would not allow for the deformation control we need. As with most background scenery, it is modeled by hand and as low resolution as possible.
This could come into more handy later if it is built into a renderer.
A subpixel displacement renderer that can nullify coplanar polys in this way (though there arent that many usually in detailed oranic objects) it could speed things up quite a bit.
The article is short on technical details but...
h tm is in wide use. In fact, pretty much all 3d gemoetric level of detail techniques rely on collapsing "flat" areas. The source data for the geometry can also compress geometric data with stuff like NURBS and other parametric surfaces which is probably much better than some sort of lossy compression. With the coming "DirectX Next", OGL 2, and newer video cards, parametric surfaces (read: infinite curve detail) will easily become the norm.
While the algo may be new, the idea certainly isn't. Direct3D has built in support for optimized meshes, the ROAM algo http://gamasutra.com/features/20000403/turner_01.
http://brandonbloom.name
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.
autopr0n is like, down and stuff.
It's a MOON!
We do not live in the 21st century. We live in the 20 second century.
This isn't about compressing the data required to store a mesh, although it will help.
This is about reducing the complexity of meshes so that they can render faster.
autopr0n is like, down and stuff.
Un-disclaimer: I'm currently pursuing a PhD in machine learning.
Yes, it is new. First of all, y'all need to read the article and find out how.
It is for two reasons, both of which are stated:
The Desbrun team's novel approach comes from the seemingly unrelated field of machine learning...
Machine learning: getting a computer to generalize (invent hypotheses) given data instances. Work in machine learning has proven that generalization and compression are equivalent. That someone has applied those ideas to 3D model compression is at least notable.
We believe this approach to geometry approximation offers both solid foundations and unprecedented results...
In other words, it's not using some hacked-up heuristics. The bias behind the generalizations it makes are solidly described, and can be tuned. Machine learning consistently beats heuristics in accuracy, so their expectation of "unprecedented results" has a good foundation.
I got my Linux laptop at System76.
The immediate problem that springs to mind for me is that current graphics cards and APIs don't produce good shading effects when the geometry is turned down. Gouraud shading (color-per-vertex interpolated across the face of the triangle) is the best that hardware acceleration will handle right now, and turning down the number of vertices will lead to problems with detailed color operations under normal circumstances (complicated lighting/shadow effects, etc.)
Shouldn't the industry be pushing further toward graphics cards that can accelerate true Phong shading, rather than shortcuts and texture mapping tricks? Or even automatic interpolation between meshes of different complexity depending on how much of the scene a particular model takes up? If that functionality was developed first, then this mesh optimization would make perfect sense. But, for now, anyway, it seems like getting rid of the geometry is going to force developers to continue to rely on tricks to get the best look out of their engines.
Not that you'd HAVE to use it, though...
C
The Sun is proof that we can't even do fire properly.
Read the fine article. You are correct that mesh optimization has been a most popular MA/PhD thesis subjects for over two decades. Which is exactly why someone comming up with a method that is an order of magnitude better than any other previous method is big news.
Also for all those questioning it's usefullness, you need not look any further than 3D scanning. When it comes to detailed models, very few things are done by scratch, instead the are digitized using one of many scanning techniques. This model is then massaged by hand by an artist. This technique would allow you to get a much better first cut, saving time for the artists.
Lastly, quake and others generated meshes from smooth NURBS objects. This is quite different, and much easier than generating one mesh object from another. Those tequniques are not usefull for scanned objects where you start with a dense mesh object.
No, what it will usher in is a new wave of whining when companies go with some proprietary method of mesh compression instead of whatever compression is eventually developed by the Ogg team.
Hey freaks: now you're ju
Skimming the article, this just seems to be polygon aggregation on the model ( not HSR, which is certainly not what grandparent was implying anyway ). It's certainly not a method for compressing the stored mesh, it's just discarding arguably redundant detail.
Desbrun explains that his accomplishment was to simplify such a mesh, by combining as many of the little triangles as possible into larger elements without compromising the actual shape. Nearly flat regions are efficiently represented by one large, flat mesh element while curved regions require more mesh elements.
( My emphasis ). I was pretty sure this was nothing new, although I'm sure a general case algorithm, let alone a fast and accurate general case would be novel. But I was writing polygon aggregation code for my undergraduate computer graphics subjects ( much simpler meshes though ), and I would expect anyone with any CSG education to not confuse the subject matter with an actual storage optimisation.
One god, one market, one truth, one consumer.
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.
I get the feeling this technique won't be so useful for what most people consider to be CAD. That is, defining the size and shape of parts. (ALA Pro/Engineer, Catia or the like) The part of CAD that I feel may benefit is Finite Element Analysis (encompased by the phrase: computer aided design). Meshes of 3D shapes can get VERY complex VERY fast and this complexity has to be stored in large files. The hangup is probably that this technique was developed to retain visual similarity. That dosn't mean that the data it retains will provide a good numerical solution.
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).