Issue link: https://digital.copcomm.com/i/5474
December 2009 40 To help sell the animals into the shots, the team used a function in Furator that runs a 3D noise field through the fur, making it appear as if a soft breeze was blowing through the animals' hair. Dialing it up resulted in the fur getting blown about, as it does in one scene that was shot on a very windy day. "e animal felt a little dead without any fur motion," says Jacobs. Ahron Bourland, technical art director, wrote a shader for the fur that enabled it to stand up in two full-frame, close-up shots of the Jacob wolf 's eyes, in which Bella's reflec- tion can be seen. As for the eye itself, rather than model a physically accurate eye with mi- nutia detail, the group focused the shot on the character reflection. "We did a bunch of focal depth blurring that helped us not get caught up and render detail that was unnecessary," says Fredenburg. "It was not about seeing the veins in the corner of the eyes or the mucus looking just right. It was about the emotional moment of seeing Bella's reflection." A texture reference from the actor was used for the wolf 's eyes, to support the book's de- scription of the wolves: that they had unchar- acteristically human-like eyes. In all, each wolf contains approximately four million hairs—more than Tippett has grown on any previous character. e studio has the technology in place to render more than 12 million, should the situation arise, contends Gardner. Furthermore, R&D is experimenting with a system for instancing geometry based on curves, which would be useful for objects such as feathers. In Motion Tippett, in fact, has crafted a number of CG animals for a number of films, from a rat (Charlotte's Web), to a chipmunk (Enchanted), to goblins and trolls (e Spiderwick Chroni- cles). e studio even did wolves for e Gold- en Compass, but the big difference here was these wolves were main characters that had to act and perform. Under the direction of Gibbons, the crew built the animation rig for the general wolf model, Jacob, within Maya, then propagated it out to the other characters. A number of plug-ins from the rigging department helped the animators achieve specific performances for the animals. Unlike many furred characters of late, these wolves have no dialog, nor do they emote a wide range of expressions. "We couldn't take the wolf out of wolf land. We had to walk a thin line in how far we could take the emo- tional moments," says Gibbons. To this end, the group developed a detailed facial rig that focused on the animal's snarl. "We kind of loaded up controls in the snarl that we normally distribute through the face rig," says Fredenburg. "I am not sure how many shapes we had, probably several hundred. We spent most of the time constructing the nose and muzzle. Wolves have this crazy ability when they snarl; it looks like they are peeling the skin off their face. It's kind of creepy. We built that in and worked with the director to find the ap- propriate level for the characters because they couldn't be too creepy or scary." In addition, the animators used a number of blendshapes, and on top of those, built a cluster rig whereby they could accentuate the blendshape results in order to get certain expres- sions. "We were going for something natural- istically real, so we didn't exaggerate shapes like you would see in a more cartoonish character," Gibbons says. In the film, the animals are shown running, jumping, breathing heavily, and so forth. "e moments when the wolves are standing, breathing, those were the controls with which we worked the most on the rigging and ani- mation sides, so that those particular moments would carry over realistically," says Gibbons. "We couldn't break the illusion of believability for the audience." e wolves were composited into the scenes using Apple's Shake. Despite all the experience the group has had with furry animals, even wolves, these animals presented a challenge unlike any other, con- tends Jacobs. e key to the project's success, notes Fredenburg, was keeping an eye on the final picture. "at is something Phil [Tippett] drums into our heads," he says. "We were not trying to write a SIGGRAPH paper with this. We were looking at the final image and staying focused on the things we needed to address in order to get the final image looking just right. We could have easily have gotten into a large science experiment with the complexity of this fur, but we boiled it down to the essential ele- ments and did a good job focusing on them." And that helped make this project a howl- ing success. n Karen Moltenbrey is the chief editor of Computer Graphics World. Tippett employed its new Furator grooming software to generate the fur on the digital animals. Each wolf model contains approximately four million hairs. n n n n CG Animals