Thursday, May 22, 2008

Motion Capture Ready to Bring Next-Gen Avatars to Gaming, Movies, Medicine, the Military and More (With Video!)

For his biweekly "Buzzword" column, PM’s senior tech editor subjects himself to a new version of the F/X rig you’ve seen before. This isn’t Chris Paul strapping on EKG-like suction cups for some sports game—it’s the geeks who brought real faces to GTA4 mapping Jackie Gleason onto Peter Griffin, and the innovators who tracked sick bodies building better a better golf swing (and maybe a whole robotic army).
The author’s transformation may look silly frame-by-frame, but the facial mapping software at Image Metrics—already implemented in Grand Theft Auto IV—could someday take performances by dead actors and sync them up with CGI characters. (Stills courtesy of Image Metrics; photo illustration by Anthony Verducci)
Only a few years ago, movie and video-game companies set out to redefine the science of special effects and makeup artistry with a new technology called motion capture. Instead of spending hours in a makeup chair each day, an actor could don a spandex body suit studded with markers that resembled ping-pong balls, step in front of the camera for a scene, then let the costume and makeup get layered on digitally. The creative possibilities were stunning: Heretofore impossible effects could be mapped onto an actor’s body while allowing for serious freedom of movement. Mere mortals were transformed into a slivering Gollum and monstrous King Kong (the same guy, actually). The graphical possibilities of movies and video games experienced a quantum leap. And, perhaps most importantly, our eyes believed.
And so, it’s testament to the speed of digital imaging innovation that what was considered revolutionary just a few years ago is already being superseded by a new generation of motion-capture technologies. Two companies in particular, Image Metrics and Organic Motion, are improving and simplifying the process in ingenious ways—and potentially opening up the field to applications way beyond the scope of merely the high-tech entertainment industry. Recently, I’ve had the opportunity to test out both of these systems, morphing myself into a variety of digital characters. [Check out in-the-lab video here; “Buzzword” continues below ...]



Image Metrics focuses on one of the traditional weaknesses of motion capture: natural facial expression. For his face to be rendered with conventional motion capture, an actor would have a series of dots painted on as reference points for postproduction software to later attach a digital “skin” to follow his expressions. This technique was used to great effect in the Pirates of the Caribbean sequels, in which Bill Nighy played the aquatic Davy Jones, complete with a beard of slithering octopus tentacles. Nevertheless, painting a face full of markers can be as time consuming and laborious as traditional makeup work, and the back-end CGI is time intensive and takes a lot of processing power.

Tracking all aspects of a face’s motion (including eyes and lips, which are difficult to attach markers to), Image Metrics then sets its software loose to automatically map that motion to a template character. Changes in the actor’s expression automatically create changes in the expression of the avatar. Here at PM headquarters, we filmed a close-up video of my face with a garden-variety camcorder (OK, not that garden variety—this is our test lab after all). We then e-mailed the movie file to Image Metrics, who used it for the video above to turn me into what I can only assume was the company’s most embarrassing set of characters.

But I was just a test dummy after a string of game developers already used Image Metrics in extensively in titles such as Top Spin 3 and Grand Theft Auto IV. And it’s starting to gain a foothold in Hollywood, with films such as Harry Potter and the Order of the Phoenix already taking advantage. In many ways, however, this kind of facial mapping motion capture is still nascent in its potential. It could, for instance, take performances by long-dead personalities and map them to new, computer-generated characters, creating an intellectual property conundrum that could be entertaining (Jackie Gleason’s face driving Family Guy’s Peter Griffin?) or profoundly disturbing (Benito Mussolini speeches mapped to the face of SpongeBob SquarePants?).

What Image Metrics is doing for the face, Organic Motion is doing for the body. The company’s $80,000 Stage system allows clients to create a 12 ft. x 12 ft. x 7.5 ft. studio with 14 cameras facing inward from its perimeter. Once the equipment is rigged and ready, the process couldn’t be simpler. At a demonstration Stage setup in Organic Motion’s offices here in New York, the system instantly calibrated itself to my body, matching my physique (what’s there of it, anyway) to a virtual skeleton, which then animated a 3D avatar.

As I moved around the Stage, my animated alter ego followed my every motion like a marionette. Conventional motion-capture systems allowed for freedom of movement without lengthy makeup application sessions, but Organic Motion’s system requires no preparation whatsoever. Plus, the fact that it can map the body in real-time makes it useful for applications above and beyond the entertainment industry. BioStage, a version of the system with specialized medical analysis software, has already been field tested at Spaulding Rehabilitation Hospital to track the gait of children with cerebral palsy.

As to other applications, the company has been playing their cards pretty close to the vest, saying only that a retail application will be announced very soon (“think golf-swing analysis,” said company spokesperson Chris Michaels). But given Stage’s ease of use, it’s not hard to imagine a future for it in the military and telecommunications space—control of robotic weaponry, telepresence and the like.

In fact, if the costs come down, Organic Motion’s creators even see a mass-market future for the technology. “In three to five years, we see this as an in-home system,” says Michaels. Which brings to mind a setup that would map your every movement—jumping, punching, kicking—directly into the game, making today’s Wii controller seem as quaint as an old Nintendo Power Glove.
Original here

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