Once they were able to create realistic water, the art department began to request how the water in a scene should look. Jacob says, “That didn’t make things easy. They might say, ‘It’s a little bit too confused, but what does that mean?' They were beginning to direct it aesthetically. That challenge continued right up until the last shot of the film.”

Dylan Brown and other Pixar animators studied the movement of fish at the Monterey Aquarium.

Pixar invited a scientist to present lectures on waves, swells and other motions. Several staff members took a trip to Hawaii in 2000 to study water and sea life. They ended up using reference footage from that trip to describe conditions above and below the surface. Jacob recalled conversations at work such as: "Remember what it was like on the boat on Thursday afternoon? I want the water like that.” Or: "Do you want it to look more like Wednesday or Friday?” They found that referring back to those experiences was more useful than saying, “I want it more choppy than angry."

Everybody had to learn and contribute to the dilemma of solving the water communication problems. The animators also had to learn to read the surge and swell, and study how fast the water is flowing. Knowledge of water’s behavior was needed to help them animate properly. Camera people needed to understand the effects of water on underwater photography. The lighting experts needed to learn how far away one can see underwater. They didn’t need to build sets beyond 100 or 200 feet, since you can't see beyond that.

Learning To Animate Fish
Figuring out how to animate swimming fish was an enjoyable part of the project for Brown. Long before the animation began there were just a handful of people working on the film. Brown and seven other members of the crew took a field trip to the Monterey Bay Aquarium, where a scientist spent an entire day with them. They saw back rooms where they nurse fish and have different species that are not on display. They got to touch a lot of things. "We had fun doing that. It was a huge learning experience for us."

Executive producer John Lasseter noticed that Dory's tail didn't move, and felt it looked unrealistic.

Their education continued when Adam Summers, a Ph.D. from Berkeley (now at UC Irvine), became their resident ichthyologist. He explained why fish do what they do and what he thought they were thinking. He explained the unusual body movements of the blue tang, which is the species represented by the memory-impaired Dory. They make an up and down motion as they swim and they rarely use their tails. Brown had noticed the movements at the aquarium, but he didn't know what they were called or why they happened.

Brown developed the movements of the animated Dory on what he had been taught. It resulted in an interesting lesson in understanding the difference between film and reality. After a screening of his preliminary motion studies, John Lasseter, the film’s executive producer, asked him why Dory rarely moved her tail.

People have general ideas about how fish swim. They wiggle their tails and flap their fins. So when you have this preconceived notion and the movements on the screen doesn’t support that, you loose believability. When Lasseter saw Dory swimming fast without wiggling her tail, it was physically correct for her species, but it didn’t look believable to him. So Brown went back and added tail wiggle. He took creative license. He says, “Fortunately we caught that early on.”