Co.Create

Fish and Tigers and Skies, Oh, My! The Visual Magic in "Life of Pi"

Visual effects master Bill Westenhofer maps the 3D world of "Pi." Plus: How his team saved moviegoers from seasickness.

Most 3-D movies use the filmmaking technology in service of yet another a story about superheroes or outer space--not that there’s anything wrong with that. But once in a while a 3-D movie comes along that pushes the art form and deepens the moviegoing experience. Life of Pi is one of those films.

Bill Westenhofer

“I was an artist before I played with computers,” says Bill Westenhofer, Pi’s visual effects supervisor, who has worked on many movies, including The Golden Compass, which earned him an Oscar. “This was the first time I felt like I could create art with visual effects.” His canvas included a humongous tank of water, a raft, and a young actor named Suraj Sharma.

Westenhofer also became a bit of an adventurer. Early on in production, director Ang Lee brought 15 people out on the ocean overnight in a storm. On that Taiwanese Coast Guard cutter, in eight- or nine-foot swells, "A lot of them got seasick," says Westenhofer, who avoided that fate. He then worked hard to assure that moviegoers would as well.

Here, Westenhofer tells Co.Create how he and his Rhythm & Hues Studios VFX team of nearly 500 people, from Los Angeles to Hyderabad, spent the last three-and-a-half years.

A Tiger Named Richard Parker

It all started with the tiger, known in the movie as Richard Parker. “Ang wanted to know whether a digital animal would look more or less real in 3-D,” says Westenhofer. “He is very research oriented. He always strives for authenticity wherever he can.” So in August of 2009, Westenhofer started doing camera tests using Aslan, the talking lion of Narnia--which he had created in 2-D; he transferred it to 3-D and discovered it was missing a level of realness.

That led to a year of previsualization, or previz, which gave the team a kind of lo-res map of the entire movie before shooting. “Off the bat, [Twentieth Century] Fox would not allow the boy [Sharma] in the boat with the tiger,” says Westenhofer. “So we went over shot by shot of the previz with the tiger trainer.” They decided to use tigers where they could on the film for several reasons: Westenhofer wanted to set the bar for our team as high as possible. “I told my team, If there was ever a time to fool your colleagues, this is it.” By shooting video of the real tigers--there were four of them--doing many of the motions the tiger in the movie would do, they helped to guide the process. “Since we’d done animals in past, we knew the technical side," Westenhofer says of his team. "We knew how to build it and push it even farther than before.”

The tigers also drove them to work harder. The Rhythm & Hues team worked at crafting Parker for four or five months until, Westenhofer says, the tiger looked “incredible.” And yet when he put it up against images of the real tigers, it still didn’t measure up. “There’s the money side of visual effects you’re fighting the pressure to say, 'This is good enough.'” They fought that pressure.

Westenhofer’s animators studied tiny details in the 100 hours of video that they attained, allowing them to zero in on little motions, such as what happens when a tiger puts down his paw: “The inside finger lands first, then does a quick roll to the side,” he says. “There’s a rebound shake of the fingers and that vibrates up the paw.” [Westenhofer details more of the tiger creation in this New York Times story.]

The Emotive Skies

"It was my job to bring examples of things that fit Ang’s direction," says Westenhofer, who needed an array of samples of the sky to express whatever emotion Lee wanted to capture. "Often my direction for the sky was, 'I want it to be melancholy or pensive or moody.'"

So Westenhofer built a library of 150 moving images of the sky. "By the way," he says, "if you’re looking for a gig in the visual effects industry, here’s a great one." One lucky employee was dispatched to Florida for three weeks on a beach. There, he had a special HDRI camera rigged to take a "much broader range of information from darks to lights. Whenever a cloudscape went by they popped off shots."

Some Rather Aggressive Flying Fish

A climactic sequence involves thousands of flying fish, which were simulated based on "tons of reference shots" that they would play in slow-motion. "While they’re gliding they stick their tail back in for second to give them another boost and continue their flight," says Westenhofer. "They can be out of the water for almost a minute!"

But it was really a blend of high- and low-tech. “There were literally people standing on the sides chucking stinky dead fish from the local fish market into the boat,” he recalls.

The Roiling Sea

Realistically rendering the motion of the ocean was the most vexing part of the process. "I was really nervous about the water," says Westenhofer. "Part of my job is to figure out how to get things to work but there’s an even more important function--which is that even when I’m terrified about something I have to emote confidence."

He was worried in particular about how to marry the actual water in the tank with the digitally crafted water. "It’s still kind of shocking that it all worked. It came down to the fact that water behaves according to physical laws and is predictable. We could do things like find the peaks per frame when the raft goes up and down, and code that into our wave function. We then sat down and matched all the fine details."

As with the tiger, they shot reams of reference--they went out on the ocean for footage, then put their digital waves side by side with the real ones to compare details like white caps and wind ripples. "It was those little things that pushed the water farther."

No More Drama(mine)

Another early concern was seasickness--for the moviegoer. After all, a movie set mostly on the ocean might prompt the illness, and Westenhofer worried that his work would be for naught if people were throwing up in the aisles.

But they found a solution: editing. "Fortunately we learned that simply cutting from shot to shot broke any problems." They experimented by showing the footage to members of the crew who were susceptible. "They were guinea pigs. When you look at continuous takes they could start to feel something but as long as you cut it wasn’t a problem."

[Images: Twentieth Century Fox]

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