Issue link: https://digital.copcomm.com/i/30784
n n n n CGI we solve each hair [feather] uniquely,” Mau- rer says. “The fur artists have the flexibility to create what they want, and I think it gives us a richness to our fur descriptions. But it has also created some overhead. The macro feather system lightened that legacy workflow and reduced the number of unique hairs we were drawing. We used to cook a fur groom with 10 million hairs overnight. Now, we’re cook- ing 10,000 quills in less than an hour.” For senior animator Pete Paquette, the birds rank among the most difficult creatures he has animated. “We paid a lot of attention to how they flew from one frame to the next,” he says. “Because we had control of literally every feather on the wing, it took a lot of attention to detail. If we didn’t touch a feather, we could tell.” The faces presented riggers with the same challenge of finding the right balance between realism and cartoon. “Birds talk, but you can’t see expression in their faces,” Burr says. “We wanted them to do more. We discovered that seeing the corner of the mouth where the beak transitions into the cheek was important; we could give them a smile that realistic birds don’t have.” An implied brow ridge also helped with fa- At top, Linda and Blu show their birds-of-a-feather lifestyle in Minnesota. At bottom, the ornithologist Tulio is about to change Linda and Blu’s lives. Blue Sky artists used procedural shaders to create all the textures, including the wallpaper, the humans’ skin, and the birds’ feathers. rector wanted the birds to fold their wings into the body and present a neat silhouette. Our complication was in defining one rig that could do both, to make the transition smooth within a shot.” The trickiest part of the rigging system to solve was the folding. Modelers working in Autodesk’s Maya built the wings, but because they weren’t yet rigged, they couldn’t fold them. “When you look at many birds, when the wing is folded, the body has one clean silhouette,” Burr says. “You might not be able to tell where the wing is. If the wing is too long or too short, it doesn’t fold right.” So, the modelers and rig- gers worked back and forth within Maya on prototypes to perfect the proportions. To meet a second challenge, of having feath- ers act like fingers, the riggers added controls for each feather at the tips of the wings. “We rigged the flight feathers so they could curl up as if they were fingers on a hand and still lay cleanly,” says rigging supervisor Justin Leach. Feather geometry drove the position of all the hairs on the feather. “You can see that particularly on the cockatoo, which has crest feathers as well as fingers,” says Eric Maurer, fur supervisor. “The animators could squash and stretch, and all the little feather barbs 12 April 2011 would follow. Usually, when we do feathers, we draw every barb as fur hair. But, having quills with all the little hairs was unwieldy for animators who wanted real geometry they could pose with traditional tools.” That and the number of feathered friends prompted the crew to develop new methods for describing the feathers. Previously, the fur team drew each barb on each feather, even when that meant drawing millions of little barbs. For this film, they placed quills for each feather using the studio’s fur grooming tools, and then, with a plug-in developed within Blue Sky’s render- ing software CGI Studio, utilized that quill to place and deform a “fur file.” “You could think of the quills as equivalent to guide hairs, but we don’t instance feathers,” Maurer says. “We have a fur file that describes the quill, and a fur file that describes different types of feather. We combine the two. We use the quill to place and deform the feather de- scription, and then replace the quill with the appropriate feather macro. We can also blend between other feather descriptions.” At Blue Sky, rather than describing guide hairs and interpolating them, the fur system interpolates only the motion. “Historically, the fur artists describe every single hair, and cial expressions, and, of course, so did the eyes. “We have eyelid controls for hand-sculpting shapes across the eyeball,” Leach says. “And rigs that squash and stretch the eye but keep the pupil and iris in perfect circles.” A Bully Solution Among the other important non-human char- acters in the film is a bulldog named Luiz (Tracy Morgan). Paquette was lead animator for Luiz, one of Saldanha’s favorite characters. “I can’t pick one favorite,” Saldanha says, “because that would not be honoring the other characters in the film. But, Luiz is one of the surprises in the movie. And, I’ve always wanted to play with a character that had a drooling problem.” The modeling and rigging challenge for the bulldog was in managing the mechanics for a fat dog with long jowls. “His neck area was the biggest challenge,” Leach says, “especially when he was looking around. Rigging colli- sions are time-consuming; it means sculpting corrective shapes.” Working with the riggers in pre-produc- tion was Paquette, who describes the job of the lead animator as: “Fostering a character to get it ready for production, finding out what works and what doesn’t work,” he says. “If it doesn’t work, we have to go back to the drawing board, and that happened with Luiz. He was a secondary character, and then sud- denly, he had a major role in the film.” At first