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n n n n CGI feet long. Rather than rattles, Jake has a gun, and he carries 257 bullets. He has 60 teeth, two fangs, and 7855 scales. Each scale is a spe- cific piece of geometry that moves in a certain way as his body bends. Animators moved the snake in Maya using layered controls, and the scales moved appropriately. “Keiji Yamaguchi created the complex rig,” Paik says. “Anima- tors could pose the character and use controls to offset and hold its form. Te challenge was with the scales. Deformers sent information about the orientation of the snake to trans- formers that contoured the scales correctly so they didn’t interpenetrate.” Fancy Duds Te biggest challenge was in simulating the multiple layers of clothing. Modelers created each piece of clothing, in detail, stashing vari- ous bits in a wardrobe database—gun belts, hol- sters, boots, vests, hats, and so forth. Verbinski and McCreery had specified that even though the characters didn’t look like they’re from the natural world, the clothing had to be photo- real. So, modelers built seams into the clothing and, as they had done for Pirates, added loose threads to the model database. “Someone could grab loose threads and move them into place in a Maya scene or Zeno, and that would take the crispness out of the clothes,” Campbell says. “And then Steve [Walton] probably mentioned salt stains and sweat stains on the clothing. We had holes, loose threads, the look of clothes that had been re-stitched.” Te first week Steele was on the show, McCreery came in with costumes and props from Universal Pictures’ wardrobe department for the view painters and look-development TDs to see and touch. “Crash really wanted everything to feel like people were watching a good-old western movie,” Walton says. During the feature film, Rango alone had 13 costume changes. “We had to rig all those costumes,” Paik says. “Because they’d mix and match costume parts, we set them up so no matter what outfit he had on, the parts would interact with one another.” Te animators would put Rango into his pose with a silhouette they liked, and then the creature supervisor would match that starting pose for the simulation pass. Usually Rango and the other characters wore multiple layers of clothing, which the character TDs simu- lated one layer at a time, starting from the in- side. In some cases, however, the layers needed to interact, and in others, the layers needed to move together. “We have built incredible simulation con- 16 March 2011 Visual effects artists used every simulation trick in the studio’s tool box, including Plume, developed for Air Bender to create and manage art-directed fire. trols into our dynamic software,” Tooley says. “One of the things we can do is paint areas where we want things to behave differently. For example, if a character is wearing a shirt under pants with suspenders, we can pre- simulate some of the costume, style it the way we want, and then tack down the shirt, almost like gluing it under the suspenders, so they move together.” ILM first used “tacks” with dynamic simu- lations in Star Wars Episode I by writing code that specified particular actions for individual CVs. Now, texture maps handle the instruc- tions, which help create the realistic result. Tat photorealistic movement is something Tooley says he doesn’t often see in animated films. Instead, he notices that crews often use wrinkle maps and other deformations rather than dynamic simulations. “When I was an effects animator at Dis- ney,” Tooley says, “we drew shadow maps, tone maps, and other hand-drawn effects on top of a character to move the clothing. But when everyone switched from 2D to 3D, it became more difficult to move clothes cor- rectly without any snagging or tangling. “[In visual effects] we have to have characters side by side with actors, so their costumes have to move right and look right. We had to work hard to get there, but it’s something we’ve been doing for a long time.” Tooley counts resolution among the most important elements in creating realistic cloth simulations. “You can tell,” he says. “If clothes look smooth with no wrinkles, they’re using low-resolution cloth. On clothing, to represent a fold, the ideal is three polygons per quarter- inch. I’d like to go higher—three polygons per eighth-inch. I think some of the Jedi costumes were three polygons per half-inch, and Rango’s pajamas were close to that. I wish it could be more, but it’s a trade-off—quality and look versus speed.” Pretty Curls, Fine Feathers For hair, ILM uses a guide-hair-based system in which modelers place curves on the charac- ters that the renderer, RenderMan, instances to create full heads of hair and furry bodies. Particular to this film were Beans’ long curls and the clumpy hair on the ill-kempt critters. Animators could place the curls using a single strand of bendable, flexible hair. To wiggle the curls during the simulation without having them uncurl wildly, the riggers put the curls in springy tetrahedronal cages. Look-develop- ment TDs managed the tufting and clumping on the interpolated hairs. “It was a back-and- forth process,” Tooley says. In one sequence, the sequence that turns Rango into a hero, an enormous hawk chas- es him through the town, crashing through buildings as he runs. When the hawk was close, each feather was a piece of geometry that deformed based on the skin movement. “After animation, a rigging artist would set up cloth meshes that represented each feather,” Paik says. “We’d manipulate the springs on those so that the feathers would collide with each other, but not interpenetrate. Since it’s spring-based, sometimes it would drag and elongate the feathers, but another deformer on top would stretch it back down to its original length while keeping the simulation.” The Gang’s All Here In addition to Johnny Depp, Isla Fisher, Abigail Breslin, and Bill Nighy, Verbinski assembled a wide cast of actors to play the 100-plus char- acters, including Ned Beatty (Tortoise John), Ray Winstone (Bad Bill), and others. Voice actors for most animated films work solo in recording booths, although occasionally a di- rector might corral two in one sound booth so they could interact. Verbinski, however, want- ed the whole shootin’ match working together, just as they do on a live-action set.