Computer Graphics World

June 2009 17 Character Modeling•Animation ■ ■ ■ ■ tion—the bends of knee, the lines of the elbow, the position of the shoulders relative to his head," May says. "But, when Carl bent his little legs inside his big trousers as he walked, you didn't see the knee bend with normal cloth simulation; it looked like he was walking with straight legs. "Our animators got really upset," May relays. " ey're used to doing subtle and important diff erences in poses to sell the acting of the scene." To fi x that problem and to give Carl's clothes a thick look with a minimum number of wrinkles that the artists wanted, the cloth-simulation crew used targeting with modeled surfaces that the simulation would approximate, and shapes based on baked simulation that they isolated to certain areas of the body. Holding onto Russell e problem with Russell was his egg- shaped face. "He's basically a balloon," Jor- dan says, "and, my gosh, that was challeng- ing. e smallest facial expression would change him and make him look too old, or too young, or not appealing." Giving him a chin to separate his head from his neck helped, but often the riggers would make their best guess and then adapt the rig based on notes from the animators and directors. "Russell is very caricatured," Clark says. "And, he's a kid, so he has to jump around and be active. But, if we moved his neck too much, he'd feel gummy, so we built limitations into the model." When Russell jumps around, he moves several layers of clothing—a shirt, a sash on top, a neckerchief on top of that, his back- pack straps, and the backpack itself with between 20 and 30 Wilderness Explorer gadgets hanging from it, all animating inde- pendently. "For cloth, we have a two-stage process," May says. "Animators perform the character without clothing, and then simulation does the clothing after they're done. But the backpack is a rigid-body simulation that runs nearly in real time." As the animators put Russell through his poses, they could see the backpack and all its parts moving, and because the software converts the dynamic movement into key- frame data, they could change the simu- lated movement. " is is the most complex clothing we've ever done," says May. "And then, we attach these two complicated characters, Carl and Russell, by a hose and a rope to each other and to a house that's attached to 10,000 balloons. e animation rig is amaz- ingly complex. Depending on how hard Carl pulls on the hose, it might move the house, the wind might push the balloons, and Russell is pulling, too." is is the situation: Carl has wound the hose attached to the house, fl oating above, around his shoulders. He's tied a rope from Russell's backpack to a knot on the hose. Carl's wife, Ellie, is a circle. She has a tiny body with a balloon head, a little button nose, a beautiful smile, and bare feet. She's bouncy. She wears hand-me-down clothes and has dirt under her fi ngernails. She's Carl's playmate and soul mate. Her photos in their house are in round frames, and everything about her is loving. We meet her as a young girl in the beginning of the fi lm, during Carl's back story, and we follow her life with Carl in one of the most emotional sequences ever created for an animated feature. Carl's adventure begins after Ellie dies: She is the underlying motivation. To carry Ellie's spirit through the movie, pro- duction designer Ricky Nierva gave her a symbolic color, magenta, that shows up in fl owers and skies, to remind us of her, and composer Michael Giacchino cre- ated a waltz as Ellie's theme that plays with twists and turns until at the end, when it becomes an action- adventure theme. Special shaders accented the ability of lighters to change host Charles Muntz's expression from kindly to sinister. we've ever done," says May. "And then, we attach these two complicated characters, Carl and Russell, by a hose and a rope to each other and to a house that's attached to 10,000 balloons. e animation rig is amaz- ingly complex. Depending on how hard Carl pulls on the hose, it might move the house, the wind might push the balloons, and Russell is pulling, too." is is the situation: Carl has wound the hose attached to the house, fl oating above, around his shoulders. He's tied a rope from Russell's backpack to a knot on the hose. She's bouncy. She wears hand-me-down clothes and has dirt under her fi ngernails. She's Carl's playmate and soul mate. Her photos in their house are in round frames, and everything about her is loving. We meet her as a young girl in the beginning of the fi lm, during Carl's back story, and we follow her life with Carl in one of the most emotional sequences ever created for an animated feature. Carl's adventure begins after Ellie dies: She is the underlying motivation. To carry Ellie's spirit through the movie, pro- duction designer Ricky Nierva gave her a symbolic color, magenta, that shows up in fl owers and skies, to remind us of her, and composer Michael Giacchino cre- ated a waltz as Ellie's theme that plays with twists and turns until at the end, when it becomes an action- adventure theme.

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