Issue link: https://digital.copcomm.com/i/77744
n n n n CG Animation clothing design is fairly few and far between," he adds. "We have a few of those, but we have a whole building full of 3D modelers." Thus, the R&D group developed a new sys- tem called C3D, for 3D cloth, that made it pos- sible to create the costumes for the hundreds of characters in Brave by building the clothes on 3D models. They tested the system on Toy Story 3 to help Ken with his costume changes, and put it into full production on Brave. Even so, for some costumes in Brave, the tailors adopted a hybrid approach, using flat panels for ruffles and folds. "The 3D modeling system was a good way to do fast iterating," Chung says. "But sometimes, when we mod- eled things on the organic bodies, the clothes didn't look right." For example, the cloth in Merida's father Fergus's kilt looked lumpy and sculpted when the simulator moved cloth modeled in 3D. Instead, the tailors created flat planes, seamed them together in an accordion shape, and let the simulator relax the pleated accordion into soft folds. "We started with Merida and Fergus," Gro- ver says. "Merida because she's a main charac- ter, and Fergus because we knew he' At top, Merida's four uniquely shaded and styled dresses became 22 costumes once accessorized. Middle, the Pizza Planet truck on the witch's table has slipped into nearly every Pixar feature since 1995. Bottom, Pixar's new animation system, Presto, helped riggers prepare multiple characters more quickly. Or, worse. "We had to get rid of hairs from Angus's mane that ended up in Merida's nose," Wise says. "It isn't like every shot needed extra work. We put the simulation through such rigorous testing before production that the inter vention was about artistic choices." An early goal, according to simulation groom and asset lead Emron Grover, was to be able to send half the shots with Merida on through without tweaking. "We got to the point where Merida's hair wasn't a big deal, and that was huge," he says. "She wasn't easy. There were so many shots. And, with all those vertices and hair layers colliding, the simulation times were pretty high, but it was a huge help to use eight cores simultaneously for her hair. Her hair was faster than her cloth simulation." 18 June/July 2012 Dresses and Tresses For cloth simulation, the team used the latest version of FizT, the engine originally devel- oped by Witkin, Baraff, and Kass for Monsters, Inc. The big change was in how the tailors modeled the costumes that FizT would move. In the past, tailors created all the costumes for all the characters in Pixar films from flat panels in the same way tailors in the real world make clothes out of cloth cut from 2D pat- terns. The 2D planes fed the simulator pristine UV coordinates. The system worked. "You can get garments that look like real clothes because you're mimicking real life," Baraff says. "The skill set needed to model clothes is pretty specific; you have to under- stand real tailoring." There was only one prob- lem: "The number of people who understand most difficult. We had two tailors working on those two. And then we got another tailor and started on Elinor and the triplets." When characters wear more than one lay- er of clothing, the tailors would model each layer in 3D (or the 2D/3D hybrid) and then send the heaviest layers to the simulator first. Fergus had the most layers, usually 10 or more including a shirt, a chain mail tunic, a leather tunic with metal studs, the kilt, a leather strap, a belt around his waist, and a cloak with a bear pelt on it. They started with his belt, worked inward, and then put his cloak on top. Although a cloth simulation could affect d be the how the hair moved, the simulation artists tried to avoid those collisions. "We didn't want to wait an hour for the cloth simulation and then another half hour to 45 minutes to see the hair," Grover says. "So 95 percent of the time the hair doesn't collide with the clothes." Adding an offset outside Merida's dress helped, and the trick was not obvious. Otherwise, some shots would have been onerous. In one sequence, for example, Merida rides Angus while holding a tapestry on her lap. "She's at full gallop," Chung says. "We had to simulate the horse's hair, Merida's hair, her dress, and the tapestry. That was a moment. Fortunately, we prepared for hard shots like that. It was the one-off's that were harder." Chung singles out one shot in particular. "Merida takes off her hood in a dramatic mo- ment that lasted 600 frames," she says. "Simu-