Animation Guild | We are 839 Digital Magazine
Issue link: https://digital.copcomm.com/i/1535742
42 KEYFRAME WHO DOES YOUR HARE? Hair should be easy. But hair is never easy. Not when you have to deal with factors like curls or kinks, how it picks up the light, or how it behaves in extreme wind or underwater. Or, as in the case of Tangled, when the main mane—belonging to Rapunzel, naturally—measures 70 feet long and must be picked up and carried, frequently during action scenes or chases. "That was an insane science project," says Steve Goldberg, the Visual Effects Supervisor on the film, explaining that Tangled was to be released in November, and the team didn't have a working hair shot until March of that year. "We were sweating it a bit," he says. Thanks to Disney's Dynamic Wires hair simulation system, Rapunzel's hair was tamed. "As far as controlling the hair and that level of simulation, Tangled was our big breakthrough," Goldberg says. "[Hair Simulation Development] Kelly Ward came up with some amazing tools that allowed us to be able to get that level of control." An extension of her Ph.D. work, Ward led the team in developing Dynamic Wires— she would go on to win a Motion Picture Academy Scientific and Technical Award for this program. The film's Technical Supervisor Mark Hammel explains: "Rigging artists would embed the [Dynamic Wires] simulation engine into hair rigs with artist-level controls." This allowed them to drive the behavior of the hair simulation, such as its stiffness, and control its relationship to objects in the environment. "Technical Animation Artists would be given guidance by the directors about how they would want the hair to move in any particular shot, and [the artists] would set up the conditions for the simulation to run," says Hammel. "[This] would produce the realistic frame-to-frame motion of the hair, ready to be rendered." On the more beastly side of things, with more than 60 species of animals set to populate the world of Zootopia (2016), Disney had to figure out how to depict fur in ways they had never done before. This was a far cry from the studio's first all-CG film Chicken Little (2005). "[Back then], many tools were developed to help ease the transition from hand-drawn to CG animation for the artists who were learning a different way of creating an animated film," says Goldberg, the film's Visual Effects Supervisor. "Traditional Background Painters were trained to become Lighting and Look Development Artists, Character Animators and Effects Animators were trained to work with 3D software rather than pencil and paper, and a number of Cleanup Artists were trained in hair and fur simulation tools." The film was a milestone, with a titular character that featured 76,000 individual feathers. Its proprietary toolsets and early in-house Maya plug-in tools laid the foundation for—just a decade later— Zootopia's rabbit and fox protagonists, Judy Hopps and Nick Wilde, boasting about 2.5 million hair strands each. This magic was achieved via a fur shader within the rendering system, along with a modern version of iGroom to control the look and movement of fur in intricate ways. top: Used notably on Tangled, Disney's innovative Dynamic Wires program advanced the way in which hair could move in relation to its environment; below: Disney's Zootopia escalated the realistic look of animal fur using in-house tools like iGroom and XGen. F E AT U R E Images courtesy of Walt Disney Animation Studios