As Hal Hickel tells it, animators at Industrial Light & Magic have been chomping at the bit to do an animated feature for quite a while. Well, they got their wish with Rango, the strange and funny film directed by Gore Verbinski (the Pirates of the Caribbean trilogy) that's a mash-up of spaghetti westerns and Chinatown, opening today from Paramount Pictures. The eponymous character (Johnny Depp riffing on Don Knotts and Jack Palance) is a chameleon on an existential journey, who becomes sheriff of Dirt, a desert town suffering from total dehydration.

And Dirt is the operative word.

"As Gore started to download his vision, we realized it was going to be perfectly suited to ILM," admits Hickel, ILM's animation director. "And the reason for that was it boils down to one thing: we've been making pictures dirty. To begin with, we knew it was going to be a unique project coming from Gore. It was not going to be group think. It was going to be a very small, creative nucleus of Gore, [production designer] Crash McCreery and [artist] Jim Byrkit. And the rest of us surrounded that. It was a personal filmmaking experience.

"What he wanted was something very different from the neat and tidy and colorful mainstream feature animation that we've become accustomed to [with computer animation]. He wanted something dirty, grimy, dusty, fuzzy. And it wasn't just an exercise in weirdness for weirdness sake. It was a real intention stemming from a love of the Sergio Leone westerns and the actors always looking so gritty and sweaty. And also it was just toward the goal of crafting a well-intentioned, deliberate, tactile world that you can believe in: something not photo-real but photo-surreal. So this concept of Dirt, which was our working title at ILM, was also the name of the town and how it should feel."

But it's not easy beating perfection out of computers. Still, ILM worked wonders in keyframing a very, parched, tactile world peopled with a bizarre gallery of desert creatures.

Of course, it helped free up the actors as well as the animators with Verbinski working in live-action mode, shooting the actors together on stage in an orchestrated chaos of performance, and using ILM's virtual set technology, enabling him to walk around the stage with a viewfinder and compose shots and record both storyboard frames as well as actual camera moves as he saw fit. Often times this either built upon moves done by the layout team or became a starting point for the layering of their work.

The first thing you notice, of course, is the eyes. They're not only very large but have some unique characteristics. "There was a risk with such large, ugly eyes," Hickel suggests. "We thought there was a real opportunity here and we looked at pictures of chameleons. There is really something soulful and cool about them that was a tradeoff for battling with this weird design. There's a lot of detail in the whites: all kinds of layers and styrations and pearlescence that pull you in without being too busy or unreadable. Not only that, but the eyes have no real cornea to bend light as it hits the iris and changes, so ILM set back the pupil and the iris from the outer surface.

"As the angle to the eye changes, using Buford [the desert toad] as an example, you'll see the magnification," Hickel continues. "It's part of giving the characters some interest and depth beyond the simple graphic representation of the eye."

Creating Dirt and the other desert environments was just as challenging, according to Tim Alexander, ILM's visual effects supervisor. "Environments had to carry the story as well," he says. "We had to step up the detail in the environments: the grit, the grime, the atmospherics. The town of Dirt has 36 buildings. We had to make it feel like they're living in dirt and be just as detailed as we were with the characters."