There were rules when it came to animating WALL•E: two arms, no mouth, no traditional shoulders. Symbols were created to convey human emotion.

"It was nice. We didn't do it as much as we wanted, but just the fact that we had an insight into the way they were thinking totally changed how we thought about a shot. You're really filming an actor doing something -- a character that's already alive, because the animators put much more of themselves into it than we ever would."

For the animators, reaching back to silent movie acting methods was especially inspiring. "Initially, there was a deliberate attempt to bring animation in much earlier to help sell the idea of more pantomime," says Angus MacLane, the directing animator. "We wanted to figure out a language for WALL•E's motion as early as story. A lot of it was [determining] first how he moved as a tool, as an appliance. It was very similar to Finding Nemo when first we had to crack the code of making fish appear as though they were swimming. In this case, we would look at how we wanted the character to appear as though it were actually a tank-based trash compactor. And so by first solving the challenges of selling him as an appliance, we would find his character."

MacLane describes WALL•E as a kind of bulldozer with a tank's maneuverability -- something like a really fast Mars Rover. The important considerations were his motion and mechanism.

"We have a set group of things to work with," he continues. "He has two arms and no mouth. No traditional shoulders, so how does he gesture? We needed symbols for human emotion. When he's doing his job, we have his shoulders go back to the base of his neck so he looks more heroic. But when he's communicating with EVE or when he's unsure of what he's doing, we bring the shoulders down in front of his stomach area and have his hands right in front of his chest. These are all visual clues.

"His eyes and hand positions are all based on dramatic context. He sees dancing on TV [from Hello, Dolly!] and then mimics it, and it grows from there. If ever there was a gag that didn't work, it would really pull you out of the movie. If you jiggle the tread a certain way, it would remind the audience that he was a machine, whereas the acting would be more anthropomorphic. It was always a balance between machine movement and vaudevillian acting like Fozzie Bear.

Pixar shares its love for robots in this film. WALL•E is the antithesis of EVE in design and emotion in every way.

"EVE was the antithesis in design and emotion to WALL•E in every way. WALL•E boxes up in a very complicated way. She is very elegant and is all circles and ovals, and he is a bunch of boxes and hard edges. Likewise, her movement is based on figure eights and arcs and his is on right angles and unrefined movements. She is a combination of porpoise meets wind chime... lots of undulated movements."

As for the humans they encounter, they are babies in space as a result of their lazy evolutionary state. They are large fleshy characters that don't move much, so Pixar adopted a less-is-more concept. No squash-and-stretch here. "The level of control for these computer puppets can very easily get them off-model, so it was a balance," MacLane advises. "You have the power to move the face around, but couldn't do it here because of the general aesthetic."

Aside from the virtual camera innovation, there were really no other noteworthy animation advancements on WALL•E. "There was nothing specific made for this film," MacLane confirms. "It was just a continuation of tools from previous films, such as a driving system for WALL•E's treads that was an offshoot of the system for Cars."

That was just fine for Stanton, who had plenty to contend with for this "unconventional love story told in an unconventional manner," in which WALL•E saves humanity by demonstrating how to get off automatic pilot and embrace life again.

Bill Desowitz is editor of VFXWorld.