Rapid Learners: How Pixar Animators Created A Very Scary River

Arlo, an 11-year-old Apatosaurus, is swept away by a raging river in the Pixar film The Good Dinosaur (Pixar)
Arlo, an 11-year-old Apatosaurus, is swept away by a raging river in the Pixar film The Good Dinosaur (Pixar)

It's a heart-stopping scene: The protagonist of The Good Dinosaur, an 11-year-old Apatosaurus named Arlo is chasing a little thief who's been stealing his family's food. Arlo's not looking where he's going and he slips and falls into a river. Panic-stricken, he gasps for air as his body goes hurtling down the raging rapids. The splashes, the currents, the rocks, the sound, the details are so vivid — you feel real fear for this animated dinosaur.

The new Pixar movie has been called "visually stunning" and "a triumph of creativity." The story takes place in a vast wilderness, inspired by the Tetons. The river is an ever-changing character that turns ferocious during storms and flash floods and dazzles in the movie's quiet and playful moments.

"This is a survival movie," says director Peter Sohn, and he knew he wanted Arlo's biggest test to come from nature: storms, cliffs, other dinosaurs and, especially, this river that snakes through the mountains.

But Sohn is a city kid. He grew up in the Bronx where his parents ran a grocery story. "I'd never really experienced this type of rugged terrain, though I'd witnessed it through movies," he says. A lifelong movie buff, Sohn says the 1953 western Shane was a big inspiration for The Good Dinosaur's landscape.

Supervising Technical Director Sanjay Bakshi says he was concerned when he realized a river was going to be central to the story. "That was a big kind of technical challenge for us," he explains. "Because we've done movies where we've had rivers, but never to the extreme of every sequence [happening] in a river."

Rivers behave differently at different times. "Some scenes it's calm and placid, other scenes it's really rapidly moving and spraying," Bakshi says. To be sure they got it right, they studied videos of rivers in various temperaments, from flash floods to gentle currents. They looked at currents from above and below the surface. They studied how light penetrates water. And they even took two rafting trips.

On the Snake River they studied a river at its most peaceful. On the American River in Sacramento, they studied white water rapids. It was a "roller coaster ride," Sohn says, with ice cold water coming at them from left and right.

The paddlers included Sohn and Bakshi, as well as animator Kevin O'Hara, producer Denise Ream and lighting supervisor Jonathan Pytko. "I told a couple of people at work that I was going to do it and they were like 'Make sure the oar doesn't bump your teeth out,'" remembers Pytko.

As he tells it, there were Class IV and V rapids. "The guide is the only person who knows what they're doing," he says. "They have six people who work at computers all day and probably don't get out that much."

The seasoned river guides deftly navigated their boats full of big Pixar fishes out of water through turns with names like "The Widow-Maker" and "The Bus Crash."

Three people fell out, including Bakshi. Sohn says he reached out to help his colleague ... but Bakshi disagrees. Thankfully, they both had cameras attached to their helmets so you can judge for yourself:

Once back at their computers at Pixar, the raft trip survivors say they consulted that footage when creating the "Swept Away" scene, when Arlo falls into the river. Sohn says their adventure convinced them that Arlo would be utterly terrified.

In The Good Dinosaur, Mother Nature is a formidable character, whether it's the river, heavy storms or flying carnivores.

"The idea of nature becoming that antagonist got very exciting for us, because you can't beat nature," says Sohn. "You could never defeat it, but you could survive it. And that was something that hit into what Arlo learns about loss and fear. You can't beat fear but you can find ways to get through it."

Ferocious or calm, the river is something Arlo must reckon with.

"He slowly realizes that this river can take him back home," Sohn says. "It essentially becomes our Yellow Brick Road."

Copyright 2015 NPR. To see more, visit http://www.npr.org/.

More On 'The Good Dinosaur':

Copyright NPR. View this article on npr.org.