However, as it turned out, the 3-D was just one of many technical hurdles. "The hardest part of the whole movie was the integration of CG and hand-drawn," Newton suggests. "That was nearly impossible and I really felt like slitting my wrists for two months. It was so difficult that I thought, 'Well, that's the end of my career at Pixar.' We could not figure out how to get these things together because everybody was animating blind and we didn't have the pipeline or anything to assemble these things together in a way that you could see both characters and the backgrounds simultaneously -- it was a big guessing game. The more I started storyboarding it, the more I realized why nobody had ever tried this. It's almost like a fugue in music, trying to keep two things going at the same time yet finding these breaks where each can take their turn and take some interest. And the thing that made the shots tricky is that most of them were about a minute long. That opening shot took the entire length of the production -- nine months."

Fortunately, Newton had the benefit of Sandra Karpman's expertise. She not only spearheaded stereo but also camera polish (and even rebuilt shots). And for the first time at Pixar, 3-D was not merely handled in post.

"What made Day & Night so hard was that our normal pipeline of layout, animation, lighting and rendering didn't apply," Karpman explains. "The 2D guys made a beautiful circle and the 3D guys made a beautiful block with square holes, so, for me, as a camera polisher, I had to push that beautiful circle through that beautiful block without ruining the block or the circle."

There was a further complication related to the proverbial fourth wall. "We only saw the 3-D world through those cards [Day and Night]," Karpman says, "but those cards are positioned as if they're the fourth wall, so I had to explain to the guy who was doing the CG animation that you can't break through this wall. And I had to position that wall based on the guys' feet. So I pushed that fourth wall as far as I could until their feet were actually connecting to the 3-D world."

In other words, all of this compositional positioning was a nightmare, especially with the CG animation becoming such a moving target. "And so it was a Rubik's cube," she suggests, "and it was insane and it was hard, but it was awesome because we all worked together. And I think this is one of the few times where stereo enhanced it and became part of the story."

And how does Newton think about his Day & Night? "I hope it'll have the same kind of effect as Dot and the Line and Duck Amuck: It'll stick with you for years even if you can't remember every event."

Bill Desowitz is senior editor of AWN & VFXWorld.