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It takes visual effects artists to bring together the animal stars of Zookeeper. Image Courtesy of Sony Pictures Imageworks. All images © 2011 - Sony Pictures.

In most talking animal movies, the look takes on a different style when focusing on the animals: quick cut and lock off on one animal after another. But not on Zookeeper. "We thought it would be great if the style of the movie stayed consistent," suggests Peter Travers, the onset vfx supervisor for Sony Pictures Imageworks, the lead vendor.

And how did they accomplish that?

"It started with the previs and we mapped out all the shots of how we wanted to get the animals to work together," Travers continues. "And it all had to be in different passes because the animals couldn't be shot together because they might attack each other. So you had to make sure the multiple passes worked cohesively with the camera moves.

"Our toughest work was when we had the animal meeting and making it look like they're all hanging out in the same environment. We also wanted to take a first pass at the ADR with the voice talent before we started shooting. This gave us the ability to plug in the real ADR into the previs and see how the pacing worked when we got into the difficult vfx shots. And we did ADR after as well to make adjustments."

The difficulty was that they were dealing with predatory animals, which had to be shot separately, lest they attack one another. Imageworks principally built fully renderable rigs and faces for two lions (Joe, voiced by Sylvester Stallone, and Janet, voiced by Cher); a monkey (Donald, voiced by Adam Sandler); primarily two bears (Jerome, voiced by Jon Favreau, Bruce, voiced by Faizon Love); an elephant (Barry, voiced by Judd Apatow); a giraffe (Mollie, voiced by Maya Rudolph); a gorilla (Bernie, voiced by Nick Nolte); a frog (voiced by Don Rickles); a wolf (Sebastian, voiced by Bas Rutten); an ostrich (voiced by Richie Minervini); and a crow (voiced by Jim Breuer).

 Thus it was a lot more animal-centric than camera-centric. This was the only way they could get through it. Travers had no previous experience shooting animals, so Mark Forbes, the animal trainer, provided strategic clues, such as which order to shoot the animals. The stakes became higher on set because they had to be very organized.

To make them appear like they're really talking, Imageworks did more CG animal faces than normal in this kind of hybrid, according to Travers. "Ordinarily, you do a lot of projection on the upper muzzle, and then CG on the lower muzzle, but every one of our animals was CG for most of the face, except for the elephants because the trunks are so distinct," Travers suggests. "But definitely the giraffe, the lions, the bears provided us with the capability of rendering the heads completely in CG.

"And we'd use projection methods to blend the CG area into the live-action area. The monkey's is perhaps the most successful performance. The important aspect of this whole thing was shooting HD. We preserved as much of the animal's facial performance and the CG allowed us to achieve that. We could blink eyes when we wanted to based on the dialogue or have the animal smile. We gave our animators the same capability to bring the performance to life much like with ADR that goes into an animated feature. We simultaneously recorded video of the actors with animation supervisor Keith Smith. Those little gestures provided by the actors help in the blending of the performances."