Some folks at Pixar, like their President Ed Catmul, offer great and true insight into the creative process. Here’s Lasseter with an excellent quote:

“I will never let a story reel go into production without it being great… I can show you early versions of the Pixar films when they are terrible. Every Pixar film was the worst motion picture made at one time or another. People don’t believe that but it’s true. We don’t give up on the films… we work, and re-work these story reels and [only] then we go into production. We then do the staging with the camera work. We go and record the dialogue with the actors. We’ll do the animation. Meanwhile, all the things that have been modeled that’s in the set and the characters has to be colored, with texture, and then it’s brought together, and lit, and we do the final rendering… it’s a lengthy process. It’s hand made… it takes 4 years.”

John Lasseter, Chief Creative Officer at Pixar, on Charlie Rose, 12/5/11