For Pixar's next release, Up, the challenges included making cloth behave on a caricatured body and bringing Venezuela's Tepui Mountains to life. All images © Disney/Pixar.

After debuting with the fantastical Monsters, Inc., Pete Docter follows up with Pixar's next feature, Up (opening May 29 from Disney's Buena Vista): a more grounded but still exotic comedy/adventure involving a 78-year-old grumpy old man named Carl (voiced by Ed Asner) and an eight-year-old Wilderness Explorer named Russell. The director presented Up at Comic-Con in San Diego last weekend, sneaking some footage of the widower and former balloon salesman using his remaining balloons to lift his house up to the sky -- with Russell as a stowaway -- on a trek to Venezuela, where his late wife, Ellie, always wanted to visit.

Docter explained that they encounter the strange and isolated region of the Tepui Mountains, thanks to inspiration from video provided by Production Designer Ralph Eggleston (WALL•E). The story of Up, written by Docter in collaboration with co-director Bob Peterson, was inspired by Docter's correspondence with Disney legends Frank Thomas and Ollie Johnston as a young animator, as well as the fascinating life stories the elderly often provide when you take the opportunity to spend some time with them.

Docter spoke with AWN after his presentation about the challenges of making Up. They're still trying to figure out how to apply main animation solutions such as cloth. For instance, Carl's head is three feet wide and he's five feet tall and he has expansive limbs. How does the cloth behave on such a caricatured body? And how do you make the Tepui come to life in a believable yet stylized way?

Bill Desowitz: This is obviously very different from Monsters, Inc. What were the challenges in figuring out this journey?

Pete Docter: It's not done yet, so I'll speak so far. I think the trick has been where reality stops and fantasy starts. A large part of this film takes place in this jungle of South America, these amazing Tepui tabletop mountains. And these really exist, but most people haven't heard of them. So you have these weird, fantastic plant shapes -- there's one in particular -- where you have these curvy leaves and a stick with a spike ball on top: it looks like something out of Monsters, Inc. It's real! So how do you present that to people where they don't go, "Oh, they're making stuff up again"? We still want the sense that this takes place in the real world -- it's not Dorothy going to Oz. It's almost more of a design challenge at this point.

BD: What helps you with the design challenge?

PD: Research. Having gone down there -- there was a group of 12 of us -- we took tons of pictures, lots of sketching. Even though you might not be familiar with that type of plant, I think there's a believability that you can feel just being a citizen of the world. You start to realize [what's natural] and [what's] a bit more fantastic. And, yeah, all the tools that give you the sense of three-dimensional lighting and textures certainly help... And we're still [struggling with it], but that's part of the fun.