Computer Graphics World

June 2009 18 e tethers form an upside down "y" with the house on top. Because animators want- ed control, they used a sophisticated rig to move the tethers, rather than rely on a simulation to create the motion. e house moves independently, sometimes reacting to balloon simulations, sometimes moving with keyframe animation with the balloons reacting to that. "In most shots, we didn't see all these things at once, but when we saw all three, generally animators performed the characters sans clothes and with the tether in a rough position for the house," May says. "Simulation ran dynamics for the clothes and, if necessary, improved the animation of the tether. And, eff ects ran the simulation for the balloons and sometimes for the house." In other words, animation fi rst, then cloth simulation and eff ects working in parallel. Iridescent Kevin Kevin, the bird, needed to be a character never seen before and dramatic enough to give Muntz, the pilot who was Carl and Ellie's hero from the newsreel footage, a reason to spend 50 years looking for her. "She was the hardest char- acter because we walked the fi ne line between too unreal and too cartoony," Jordan says. "Pete said that when the audience fi rst sees her, he wanted her to look like she's made of gold when the sun hits her, but that she really could exist in nature." e art department found im- ages of a Monal pheasant from the Himalayas that has iridescent feathers in metallic green, purple, red, and blue colors, a copper-colored tail, turquoise blue skin, and a blue crest like that of a Eight-year-old Russell, a Wilderness Explorer who inad- vertently stows away on Carl's adventure, takes Ellie's place as a circle in Carl's life. Russell rolls joyfully through life, excited, constantly circling around. He looks like a little egg with stubby arms and legs and no neck, and he wears a backpack loaded with Wilderness Explorer camping gear, a neckerchief, and a sash covered with Wilderness Explorer buttons. The technical challenges for Russell were in creating facial features and expressions that looked appropriate on his smooth, young, oval face, and in simulating all his layers of clothing and gadgets. June 2009 18 never seen before and dramatic enough to in metallic green, purple, red, and blue colors, a copper-colored tail, turquoise blue skin, and a blue crest like that of a Eight-year-old Russell, a Wilderness Explorer who inad- vertently stows away on Carl's adventure, takes Ellie's place as a circle in Carl's life. Russell rolls joyfully through life, excited, constantly circling around. He looks like a little egg with stubby arms and legs and no neck, and he wears a backpack loaded with Wilderness Explorer camping gear, a neckerchief, and a sash covered with Wilderness Explorer buttons. The technical challenges for Russell were in creating facial features and expressions that looked appropriate on his smooth, young, oval face, and in simulating all his layers of clothing and gadgets. Carl tied a rope from Russell to a hose he's using to pull the fl oating house. Creating the fi nal image at top required water simulation (above, far left), character animation with rigid-body simulation for Russell's pack and a sophisticated rig for the tether (above, second from left), cloth simulation (above, second from right), and shading and lighting (above, far right.)

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