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ILM Maximizes Vicon Motion Capture For Vampire BridesInnovation in shooting motion capture elements for Van Helsing. (May 21, 2004)
Vicon, the leading developer in motion capture, announced that a Vicon motion capture system and 24 high-speed, high-resolution Vicon MCam cameras were used by Academy Award-winning visual effects studio Industrial Light & Magic (ILM) to capture performance animation for Van Helsing. Combining the accuracy and flexibility of Vicon motion capture with high-powered, light-emitting markers, ILM customized an approach for the 2004 summer blockbuster that allowed it to effectively shoot motion capture on a demanding film set.
Van Helsing, directed by Stephen Sommers, spins its tale of adventure and suspense around familiar horror figures and a universe of rich, imaginative visuals. Dracula, Frankenstein and the Wolf Man find a force to be reckoned with in the titular Van Helsing, and the action soon sweeps the audience into a space and time where men morph into monsters and tongue-in-cheek terror reigns.
Among ILM's formidable assignments as the movie's principal visual effects company were Dracula's brides, who transform in appearance from sultry females to blood-thirsty vamps. These monstrous brides use bat-like wings to fly through a Transylvanian town, attacking villagers. While doing so, they are struck by arrows, cut by knives and stabbed by stakes. There was no easy way to accomplish these effects purely with makeup and costuming; digital bodies were required, yet the live-action facial performances of the brides were critical.
"Stephen really wanted to emphasize the actresses' actual faces and hair, yet he needed to use digital bodies to accomplish the look and performances he sought," said ILM Motion Capture Supervisor Doug Griffin. "We knew we were going to need a high degree of control over their bodies in post to incorporate CG wings and other creature effects. This led us to create a 'hybrid bride' approach whereby we captured live-action footage of their head and hair at the same time as motion-capturing their bodies. Later on, we could combine these elements to produce the overall result."
Forty-five shots were filmed this way over two weeks, using Vicon cameras surrounding the set. Because this was a film shoot, the set was brightly lit and crewed by a full complement of grips and practical effects personnel. ILM was able to maximize the motion capture technology, even in this bright and busy environment. "Motion capture systems reflect light off of markers placed on the performer. These reflections need to be significantly brighter than any other light on the performer. Given the intense light of the film environment, standard markers would not suffice. So we developed custom active markers using high-powered infrared LEDs. Although these provided very bright light sources that were easily visible by the Vicon system, they were outside the visible light spectrum and therefore invisible to the naked eye," Griffin explained.
The actresses, adorned with vampire makeup, wigs and one-inch contact lenses, were suited from the neck down in blue and moved with help from a harness and stunt puppeteer, also clothed in blue. While the motion picture camera filmed their facial performances, Vicon cameras tracked the fine movement of their bodies. With grips, wind blowers and other crew blocking or bumping the cameras, producing accurate motion capture data became a trickier feat still.
"To be able to marry the live-action footage with the 3D body, precision motion data was key," said Griffin. "You normally don't want your motion capture cameras occluded by lights or gear; here, we knew the wind blower was going to have to block us at points and we knew our cameras were going to get bumped around. That's where Vicon's iQ software tool called Camera Re-Section really worked to our advantage. If cameras were bumped accidentally, or purposely moved to get a better angle, we knew we could still recalibrate the cameras to get the data in post."
The motion of the film camera itself was motion captured using Vicon. The resulting 3D motion data helped ILM speed up and improve the match-moving process in post. This technique gave director Sommers immediate control over how the shots would look because he could direct the film and motion capture performances simultaneously. That level of comfort further empowered the director to add dramatic appeal to the bride shots.
ILM is a Lucasfilm Ltd. company serving the digital needs of the entertainment industry for visual effects. ILM has been awarded 14 Academy Awards for Best Visual Effects and received 17 Scientific and Technical Achievement Awards. Recent credits include: "Pirates of the Caribbean," "Harry Potter and the Prisoner of Azkaban," "Master & Commander: The Far Side of the World," "The Day After Tomorrow," "The Hulk" and "Hidalgo."
VICON Motion Systems is a subsidiary of OMG plc (LSE: OMG) with global headquarters in Oxford, UK, and US headquarters in Lake Forest, CA. OMG subsidiary 2d3 Ltd. produces innovative visual geometry software deriving 3D data from moving images. Since 1984, VICON has been providing professionals with the latest tools to accurately capture the subtleties of three-dimensional human motion for research, medicine, sport, engineering, game development, broadcast and film. For more information about VICON, or to view a comprehensive list of worldwide distributors, visit www.vicon.com, or contact +44 (0) 1865-261800 in the U.K. or (949) 472-9140 in the U.S.
Related Keywords:ILM, Vicon, Motion Capture, Van Helsing, Vicon MCam, Industrial Light & Magic, Stephen Sommers, Doug Griffin, Vicons iQ, Camera Re-Section, Lucasfilm,