Computer Graphics World

October 2008 36 n n n n Animal Modeling new version of RenderMan had a slightly higher memory requirement, which in it- self wouldn't have created a problem, but coupled with everything else became an- other ingredient in the soup. "We normally don't render in 64-bit mode because it is a little wasteful," Liedtka says. "But, we did switch to the 64-bit ver- sion of RenderMan for a few shots to ac- cess more memory and hardware. It was the most straightforward solution." Tippett uses Furocious, a proprietary fur system, to groom and move the hair, and the R&D department is currently in the process of re-writing it. "It really looks good," Liedtka says. "We have a dog with a collar, a rat pick- ing up and carrying things, interaction be- tween the characters, and a CG animal riding on the back of a live-action animal." As with many fur systems, the model department cre- ates guide splines to do a rough groom, the paint department adds further grooming and color, and then the TDs run simulations on the guide hairs. "Our fur tool has gotten really robust," says Colin Epstein, compositing supervisor. "Before, we'd be in the 30 percent range, so we'd do a softening pass in compositing to make it look less prickly. But, now, we're in the 90 percent range. e fur comes out of rendering looking so much more organic. It frees us to do fine-tuning and finessing; our work is subtler by comparison. We just check focal depth, edge detail, and tweak a little bit here and there to get the animals to sink into the image—that last 10 per- cent gives us the seamless results." Going to the Dogs After lessons learned on Manuel, the tech- nical crew persuaded the art department to keep the fur count down for the digital stunt doubles and to make sure that the director approved those digital characters with a more reasonable number of hairs. "We didn't have any problem with the digital stunt doubles," Liedtka says. "e big German shepherd dog with shaggy hair looks great." For the most part, Tippett's digital stunt dogs appear in action shots. "We got the shots that real dogs couldn't do—jumping from a train, one dog carried in the mouth of another dog, and so forth," Brown says. "We had to match the real dogs, but Tip- pett is very good at matching live action and making it look the same." For reference, they used DVDs, You- Tube, and brought live dogs into the stu- dio. "Having live dogs is best," Brown says. "You see little nuances you might not see in a video, and you can feel what the dog is doing. You get to hold the dog, feel how muscular it is, and really discover what makes the dog move." In addition to the digi-dog perfor- mances, animators also created cycles for the studio's proprietary crowd system to populate scenes with dogs hanging out, cheering, barking, and chanting "No mas." As many as 240 Chihuahuas appear in some crowd shots, and the dogs are digital. "It was a bit more complicated than usual," Epstein says. "We were going back and forth between other studios, and some- times we were adding crowds to back- grounds that didn't exist yet, so that kept us on our toes." e compositors received crowds ren- dered in small sections so that animation changes, if necessary, could happen more easily. "If we had three dogs facing away from the camera, we wouldn't have to re-render the entire crowd," says Epstein. Compositors also adjusted the colors to, for example, dim white dogs that might draw attention away from Chloe, and change the color of black dogs that, when grouped together, looked like dark holes. And, they often fixed shadows. "We had a massive temple set covered with Chihuahuas," Epstein says. "We didn't have time to finesse each dog into each section of the plate on the 3D side, so we used our 2D magic. Sometimes it's easier for us to apply a rotoshape or garbage matte to the dogs to cast a shadow that the TD didn't do or match a shadow falling onto a character." In addition, the compositing team cre- ated a shot with a German shepherd and a Doberman squaring off by re-purposing an existing plate. In the original plate, a real German shepherd acted like it was trapped under Styrofoam rocks. But, the shot design changed to have the dog be- neath an intact archway instead. Rather than rebuild the set and bring back the canine actor, Tippett assembled a digital set and placed its digital stunt double in- plate of an intact archway, and then as- sembled the result into the original plate with the Doberman. A quick, last-minute change like that might seem like another day on the job to the Tippett crew, but it's a sign of how far the visual effects pack of artists and anima- tors have evolved. at doesn't mean we should take the sleight of hand that Tippett performed for granted. "e scenes with Chico and Man- uel are some of the most amazing scenes we've done," says Brown, who received a VES nomination for his work on the chip- munk Pip in Enchanted. "ese characters hang onto each other, touch, sit on each other, and protect each other. You can see the weight and mass of each character as they interact." It's a sweeter moment, though, that pleases Brown the most. "ere's an in- timate scene, a tight shot, when Chico persuades Manuel to do something and Manuel realizes he needs to," he says. "And then Chico congratulates him for doing a good thing. You aren't watch- ing CG characters. You're watching two friends have a moment. You believe that these two characters care for each other. at's what we strive for. I think we knocked it out of the park." n Barbara Robertson is an award-winning writer and a contributing editor for Computer Graphics World. She can be reached at BarbaraRR@comcast.net.

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