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UCLA Adds Physics to Prat-falls
BaltoAaron writes "CNN.com is reporting on Petros Faloutsos , a UCLA scientist, that has developed a program that creates animation based almost solely on physics. Faloutsos "believes his animation program will one day allow virtual stunt artists to replace their flesh-and-blood counterparts in performing otherwise deadly feats of derring-do." "It's the Holy Grail of character animation. Everybody wants to do it, but there's not a whole lot of it out there right now.""
This guy http://www.q12.org/phd-movies.html did a physical body *and* made it walk with artificial controls. (And he's developed a library for the physics called ODE which makes doing a body falling down stairs about a days work, maybe half.)
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Havent the video game makers created a program that creates animation based almost solely on physics yet? ;)
Sure, there's nothing I want more than to see a film where someone fires a gun at Keanu Reeves, and then he turns into a "Grand Theft Auto 3" style character made of polygons and falls to the ground with blood squirting out of his aorta.
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You could get into the program and change a variable or two and have your characters looking like they really are on a high-gravity or low-gravity planet, or in the viscous atmosphere of Jupiter, or whatever you like! I'm looking forward to it.
Now we'll get to see the three stodges remade with Cowboy Neal, John Katz, and CmrdTaco punching each other using computer physics. What a great world.
I remember thinking that something about it looked unnatural, even a little cheap. Now I know it wasn't a low budget effect, just a new technique.
While this may one day create much more realistic effect in film, I'm not sure it's quite ready yet. Did this scene stand out for anyone else that saw this flick as a little "off"?
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Haven't special effects wizards been using physics simulators for movie effects and video games for at least a few years now? Sure, this may be more advanced then previous physics engines, but is it really something revolutionary?
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DANCE is a portable, open, plug-in based, object-oriented software package for physics-based character animation. It runs on Linux, Irix, Windows 98/NT and is being ported to MacOS by Joe Laszlo. One of its goals is to provide researchers with a common platform where they can test their control methods and share their results. In addition, it provides the common, yet complex functionality that everyone needs in a physics-based animation system, allowing researchers to concentrate on their research work. Dance has been used for a variety of physics-based applications that include biomechanics modelling and composeable controllers. For more information, please contact the authors.
It's available to download and play with!
well if they can get the power to do it so be it.
Every computer generted graphic movie thus far has failed but no one is totaly sure why. Final fantasy though excelent with the eye popping candy you realize that is is just a computer after 5 mins of enteraction. I dont see this comming to true fruition as of yet. But yes it would make for alot better FX. Some times i just watch a movie for the FX.
The thing that worrys me most is that from most films eye candy takes up for true plot. Now if we can make a computer that can make really good plots the movies will rock.
But this does sound alot better then bill hicks idea of using the termanaly ill and people sentanced to death to do this work. Though it still is kinda appealing.
Kudos to any one that can pull it off am sure they will who knows one day we can all make gore fest as a plug in to adobe premere.
There has been research in this area being done for years, much of it presented at SIGGRAPH. There are techniques to animate characters through intricate plots just by specifying behavioral charactics, techniques to apply motion dynamics to characters of significantly different shape, and even "video puppetry" that allows images to self-animate in response to speech. All are a number of years old. All were hailed as holy grails. This just seems to be a case of CNN finally noticing.
At last year's SIGGRAPH, everyone already knew about polynomial textures, because there had been a news story about it. To me, though, the highlight of the show was that it is now possible to walk around with an uncalibrated, handheld camera, and completely automatically get a decent 3-D model out of it (textured, of course). No news story about that.
Kinda, but its always a pretty significant simplification. Only recently games have started adding things like Inverse Kinimatics(IK) in order to create motion sequences that are not just replays of motion capture.
These days a game programming text looks like an abridged edition of a scientific modelling text.
A big part of the trick is to have a realistic model of the human body. There are hundreds of joints of several varieties and many muscles controlled by the worlds most complex single entity(the brain). This makes it very hard to come up with a 'first principles' model. This is why most animation packages today (AFAIK) model the human body as a series of rigid parts(bones) connected by springs(muscles) with control points that the animator can use(the brain).
Kevin
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Years and years...
http://www.animats.com/
Physics-based animation has been a hot topic in computer graphics for a decade. SIGGRAPH made a major award to Prof. Andy Witkin of Carnige Mellon in 2001 for major progress in this field. This involves anmal motions, objects colliding, objects shattering (e.g. Phantom Menace) and so on.
Wow, all one-year-old SIGGRAPH papers should be slashdot stories.
This is the death of competitive FPS games as we know it. No longer will we be able to change our jump direction in midair, jump 7 feet through windows, run tirelessly carrying 750 rounds of ammunition, and get hit by blast damage through walls.
On the upside, the blood & guts is going to look a lot cooler.
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Well, the trouble with using it to replace stuntmen has as much to do with the realism of actual footage of an event vs a cgi simulation of one.
That is, there are many other factors that cgi imagery comes no where close to mimicking, so even if tommorow this software let you create completely realistic human animation, it wouldn't put the union out of business yet.
Many of the more spectacular stunts in our favorite action movies...such as the ones in crouching tiger...used the computer simply to composite the scene elements (like replacing the ropes from the flying harnesses), rather than recreate the scene. Or that train crash in Die Hard 3. The computer is often used to combine several "real" footages (like combining the actors on one set and the dangerous stuff on another) rather than do a whole scene, anyway.
However, games could be great with this tech. I have always wanted to see a realistic fighting game, one with actual full physics animation, medical grade damage modeling (and when someone is hurt, realistic degradation of their performance), and the completely unscripted movements that an animation engine like this would allow.
For instance, if someone punched your on screen avatar in the gut, your character would first stagger with the blow, and then shake back and forth as he tries to catch his breath. If you hit one of the attack commands at that moment, the subsequent attack animation would be modified by him still recovering from the blow, as WELL as what the other player was doing. A compltely freeform system. Yes, I know its possible to fake some of this now but there are some obvious limits. For instance, no matter how hard or how light your avatar got punched, he will probably still stagger with the same animation.
And of course the "beowolf cluster" of all these technologies : a massively multiplayer online game where you can run around fighting other avatars like above, as well as casting spells, killing monsters, leveling, looting, camping, kill stealing... All the rest of the good things we come to expect from games of this type
I seem to remember for example that normal character run speed in Unreal Tournament is over 30mph. They also tend to disregard inertia for enhanced control.
Game engines could be modified for spatial realism. The Unreality Project for example. The problem is applying that technology for character models.
Regards
I like teamwork. It's easier to assign blame that way.
Of course, there are definite advantages to putting sensors on someone's body.
If I fall down the stairs, what's going to happen to, say, my right arm, wrist, and hand? Sure, if I'm unconscious, that will all be dictated by physics - I'll flop around like a rag doll and you can nicely see all the reactive forces at work.
But if I'm conscious, how is the programming going to emulate my increasingly desperate attempts to keep from breaking my neck?
It seems to me that a better effect would be captured simply by hooking up motion sensors to a stuntman, telling him to take a five-minute break, and then throwing him down the stairs when he wasn't looking. The "mechanics" realm of physics has relatively simple rules; panic does not. So far, we don't have any formulas for the interaction of perceived danger, temperament, adrenaline, and what have you.
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Half a bottle of used beer?
Infuriate left and right
I'm willing to believe that this is a new and sophisticated tool, though I see there are already a bunch of credible posts about prior art (I go to SIGGRAPH, too).
My issue is that a lot more than physics needs to go into an animation. There's brain up there controlling all those muscles, it's not just a bunch of sticks and rubber bands. A character animator is an *actor*, part of his or her job is to give the appearance of intention to a character's performance.
Falling down the stairs is (relatively) easy. Show me the panic the moment he realizes he's lost his balance and can't stop himself. Does he flop like a drunk or roll out like Jet Li?
You still need to control a character with a human brain, whether that brain belongs to a mocapped stunt man or an animator.
The researcher performed this work for his
Ph.D. thesis at Toronto. Though he is
most likely continuing the line of research
as a professor, the article is about his
thesis work.
"Inverse kinimatics" was added to such modeling/rendering programs as SoftImage back in the early 90s. You could "drop" stuff and have it bounce around or blow in the wind or act like jello or whatever. Yes, even fall down stairs.
You just create your model and connect the "bones" (fundimental objects that move) via articulated joints that could swivel in any direction you specify. Then determine what forces are acting on it (gravity or wind for example) and stuff like how the objects interact (do they bounce? or stick?) and then just hit "play" and off it goes...
What's the big deal here?
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That sounds amazing. Does this mean that a formerly HARD AI problem (vision & representation) is now solved?! Do you recall any names or something, so that I can look for more information?
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in watching Jackie Chan movies :-)
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I thought Terry Gilliam was the Holy Grail of anima.. oh nevermind..
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Since when have movies cared about physics? I mean, in Speed the bus "jumps" an unfinished section of an overpass.
And when was the last time you saw a movie where the explosion is seen BEFORE it is heard?
Not to mention virtually every space fiction movie ever made with the sole exception of 2001.
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Are you absolutely sure you want a fighting game that's realistic? Millions of people would complain about "play balance" in a realistic game. Face it, if you hit someone, physics dictates they're going down unless they take drastic measures to counteract that. And like you insinuated, if they take drastic measures, it leaves them open for more punishment. That's why, in real fights, it's almost always the guy who connects first that wins. And medical-grade damage modeling is definitely something you don't want. In almost every fighting game ever made, hitting someone in the stomach staggers them back, but that's about it. From (unfortunate) experience, getting hit in the stomach actuallymakes one double over and takes you out of the running for a minute or more.
Let's face it...reality isn't fun. It takes a lot of money put from a special effects budget to make a movie look exciting. And that's because in real-life, things just aren't that cool.
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Faloutsos' work is not actually focused on the physics models, but on the control programs for the virtual actors. This allows dynamic, force-based animation (as opposed to kinematic, position-based animation). Each model has a set of controllers for various tasks like walking, running, jumping forward, moving from a prone position to a standing position, etc. Each controller knows its "competencies" -- the conditions under which it can successfully guide the model. These are used to hand off control from one controller to the next as the model goes through a complex motion or reacts to external forces.
The sample movies that Faloutsos showed were mostly unscripted. They would start with a model in a simple standing state, which would then respond to user-controlled forces like pushing or throwing simulated balls at the model from various angles. Various balance-recovery controllers would take over depending on how the model was displaced; if none of them were succesful then the model would fall down, and then use one of its controllers for returning to a standing position. All of this appeared incredibly realistic and human.
Also, as another poster noted, DANCE is available under a "free for non-commercial use" license (not free under the FSF or Debian definitions, but a good deal in my opinion). He encouraged us to try it out, explaining that research like his has suffered from a lack of common infrastructure, leading to a lot of reinvented wheels. He expressed hope that the DANCE framework would allow more innovative research with less duplicated work.
Everybody knows that the Road Runner cartoons are based almost entirely on quantum physics.
http://www.cs.ucla.edu/~pfal/animations.html
Err not really. Maya has simulators for very specific circumstances. Every time a movie studio needs to come up with a new solution, something new has to be written in order to get the computer to do it. I think what this article is talking about is setting up a simulation so dynamic that nearly anything can be simulated, that's yet to be done today. The technology used to make a ball bounce is not the same technology used to make a skirt cling to Aki's body.
"Derp de derp."
I think it'd be fun to play with a physics simulator of sorts, but to be honest, I'd rather have a tool where I can change or even invent my own laws of physics. Take Yosemite Sam for a moment: somehow he can survive a shotgun blast in the butt. In reality, his butt'd be missing a few important pieces, but in Toon Town, the unexpected happens.
Physics are.. well.. expected. If I could change the rules around a bit, I could create fun yet silly little movies. Remember that Far Side cartoon where a black hole suddenly formed in that guy's apartment, and everything started getting sucked into it? Heh I could animate that! Let me tweak the physics a bit, and I could really have some fun with it!
"Derp de derp."
A good model to follow would be the kind of cartoon violence in movies like Die Hard, etc. Bruce gets hit with a lead pipe. He reacts with the full *force* of the impact (ie. he gets sent flying to the ground) but he gets up again - limping, with a bit of blood on him, but otherwise OK.
When I shoot a rocket at someone in Quake, I expect them to react to the blast more than by just loosing health. They should be sent flying, or at least knocked over. Same goes for anyone close to them. So as not to affect game-play adversely, the blast radius could be kept unrealistically small (and fall off quickly) but within it I expect realistic reactions!
If I shoot someone in the shoulder with a gun, they should react. They might do a quarter turn on impact, even though the amount taken from their health is the same.
Remember what the goal for FPS is: fun violence. Make the game more realistic but don't go overboard at the expense of fun.