Oscar lore is full of tales about the winding roads that many movies travel to reach their nominations. In the animated feature category, all the nominees have lengthy backstories because the process typically takes three years or more. And this year’s nominees — Disney/Pixar’s “Wall-E,” Disney’s “Bolt” and DreamWorks’ “Kung Fu Panda” — have histories marked by screenplay twists and staff changes that could have taken the finished product in very different directions.

“The original idea for ‘Wall-E’ existed for almost eight years,” explains writer-director Andrew Stanton. When Stanton began scripting his futuristic robot love story in 2002, the film’s “humans” were completely unrecognizable, looking more like blobs of green Jell-O.

“Initially I liked the idea that humanity was so devolved that it had visually changed,” says Stanton, who imagined a “Planet of the Apes”-style reveal at the end. “I thought it would be funny to see gelatinous people with eyes like fruit inside.” But in practice, the effect was too silly, whereas identifiable people underscored the effect of centuries spent in a state of antigravity sloth.

Given the effort and expense of actually animating a CG feature, the key is to lock down the script early on. For that reason, fully rendered “deleted scenes” are virtually unheard of in the medium. “We only animate a section of the film when we know it’s working, and so all of our second and third tries … are in storyboard form,” the director explains.

To Pixar’s credit, Stanton requested (and received) permission to change two minor scenes “that I had wrong all the way through to the finished animation.” The result: a stronger film, earning Stanton his third screenplay nomination.

While Stanton worked on “Wall-E,” his longtime Pixar colleague John Lasseter was busy re-engineering Disney Animation’s “Bolt,” a project relatively early in development when he took over the company’s creative reins.

Because Disney is relatively new to all-CG features, Lasseter was very hands-on with first-time helmers Chris Williams and Byron Howard, whom he appointed to replace original director Chris Sanders (the “Lilo & Stitch” helmer was working on a variation of the story called “American Dog” in which the character starred in a secret-agent show, instead of believing he had superpowers). “I wouldn’t have put them in that position if I hadn’t absolutely believed they could do it,” Lasseter asserts.

Dividing the work, Williams focused on story reels and layout while Howard tackled character design and animation. “They were phenomenal leaders, and they let their team share creative ownership,” says Lasseter, who has since tapped Howard to co-direct “Rapunzel” with “Bolt” story lead Nathan Greno, who’ll make his directing debut. “I’m trying to break down the hierarchies and give people a chance to take the next step up,” he says.

In both look and story, “Kung Fu Panda” might have taken a completely different form, which is perfectly normal for the creative process, says DreamWorks co-president of feature animation production Bill Damaschke: “It’s an amazing combination of running a marathon and working in an emergency room.”

Things were still very rough when DreamWorks story vet John Stevenson agreed to direct. “I just hated the character design and some of the decisions for the look of the picture,” he recalls. “It’s actually physically impossible for me to work on something I can’t stand to look at.”

So Stevenson made a suggestion unprecedented at DreamWorks by championing a single artist, Nico Marlet, to redesign the entire cast. Working in a five-week window, they sold topper Jeffrey Katzenberg on Marlet’s sketches, which brought a unique — and unified — look to the world.

But “Panda” still faced story challenges, something Oscar-nominated stop-motion animator Mark Osborne had to address when he signed on to co-direct six months later. At that point, the Furious Five were the focus, and Po the panda was a decoy side character caught up in a “Kagemusha”-style scam.

“You make a lot of mistakes. That is an integral part of the process, the necessity to try and fail and learn and hopefully course-correct,” Stevenson says. “We were able to turn the supertanker around early enough so it became a Po-centered story.”