Audiences have responded positively to Tim Burton's Alice in Wonderland 3D, which has enjoyed strong box office. The movie—which was shot in 2D—got its visual effects and its 2D-to-3D conversion at Sony Imageworks. Recently, Sony Imageworks opened its doors to a few reporters to give a behind-the-scenes look at the visual effects and the 3D conversion.

Burton and Depp

Senior visual effects supervisor Ken Ralston described the project as “stuffing four years of work into two years,” adding, “Every frame of this movie was touched.” He said that as soon as he heard that Alice in Wonderland would be directed by Tim Burton, that's all he needed to know. “I’d always wanted to work with Tim,” he said. “I got in touch with [producer Richard] Zanuck and found out they’d been talking about me. I flew to London to meet with Tim and we hit it off, because we had similarly weird upbringings. From there, it took off so fast.”

First up was character design, including how they'd be animated. Since Alice would be wearing a blue dress, green-screen was used to shoot all the major characters. But aside from those main characters, everything was green and no other characters were figured out yet. He brought up the example of the execution scene. 

“When the Red Queen, at the execution, is surrounded by her sycophants, none of those characters were there,” said Ralston. “It was just stunt people clad in green.” Being around all that green for so many days was also surprisingly—and extremely—fatiguing.

Although there was some talk of animating the characters via motion-capture, it didn’t work with the style of the movie. “We started off trying to approach it with mocap but threw most of it out and did most of it with [keyframe] animation,” he said.

A second shoot took place to bring in the extras surrounding the Red and White Queens around the execution podium. “We had to match angles and lighting from the first shoot,” said Ralston. “We had to put all the pieces together as a rough for Tim, who was cutting it. He is great. He cuts early on and locks in on scenes. He didn’t do a whole lot of big changes.”

Dave Schaub, animation supervisor, showed the line-up of more than 30 animated characters in the film, including familiar ones like the Cheshire cat, dodo bird, caterpillar, as well as horses, flamingos and pigs. Some of the characters are “hybrids,” said Schaub, pointing out that Stayne (the Knave of Hearts) was created by placing Crispin Glover's head on top of a 7' 10" CG body.

Tweedledee and Tweedledum are fully animated. We showed early concept art to see what Tim responded to," said Schaub. "When we saw them as twins, he latched onto the creepiness of twins with The Shining characters." The scale of the Tweedles relative to Alice constantly changes. At times, [Tweedledee/Tweedledum portrayor Matt] Lucas had to act on stilts (to create the illusion of Alice having shrunk) but the result was that he looked like he was on stilts. “The issue of weight and physics was tackled in animation,” said Schaub. “We could plug in a run cycle into any sequence we needed [to replace the stilts]."

Lucas' head was scanned and the topology of his face was integrated into his model. They rigged his face based on the actor's expressions, so his facial performances were animated precisely and the eyes and mouth matched the performances.

Every imaginary character posed unique challenges. For the Cheshire Cat, the design possibilities were endless. The most notable expression is, of course, the smile. Burton wanted the smile to spread across the face—showing teeth for the entire grin—without the face bunching up in wrinkles. Jabberwocky, the creature that Alice confronts in the epic battle, ended up looking like a dragon, much like the illustration in the original book. But he moved differently. His large wings are used as arms to balance himself. "He moves like a large, creepy insect," said Schaub, who noted that “the moment of his reveal is a tribute to the ‘Night on Bald Mountain’ moment [in Fantasia].” The character is voiced by Christopher Lee, Schaub said, with poses and nuances inspired by Ray Harryhausen.

Visual effects supervisor Carey Villegas noted that one of the film’s biggest challenges was to bridge the gap between live action and animated characters. “Tim really wanted the characters to be immersed into the environment,” he said. “He wanted some visual glue to make the CG characters more life-like and put the live characters into the fantasy realm.”

Villegas showed examples of some of the subtle visual effects tricks that were accomplished. “We took footage from Ed Wood, a previous Johnny Depp/Tim Burton collaboration, and took elements from Depp’s eyes to enlarge the Mad Hatter’s eyes,” he said. “Tim loved the idea, so we moved forward.” To further the Mad Hatter's integration into the environment, they manipulated the color of his skin and eyes. “Subtle changes in his costume colors also gave the character magical qualities,” said Villegas. “In one point, his tie perks up. At another point, his eyes and grin become more like the Cheshire cat.”

For the Red Queen, the trick was to enlarge her head but without her getting much taller. “Tim wanted her to be nice and petite,” said Villegas. “Since the Queen spent a lot of time when Alice was 8 feet tall, we had to have tools that were flexible with all these scale changes. We worked closely with Colleen Atwood, costume designer, to match the head back into these costumes. Early tests helped us understand the technical challenges. We were able to scale not only the head but the body.”

The second aspect of the Red Queen is the cinching of the waist, which involved a frame-by-frame warping. “The biggest challenge was when her arms are by her side, because we didn’t want to impact her arms,” said Villegas. “We used a number of techniques including a GenArts plug-in, mesh warping and distorting.”

To deal with all the changes in scale, they used 4K resolution images. “The 4K frame allowed us to scale the Red Queen’s head and put it on the body. We scaled the size of the head we wanted from the 4K frame, and then warped it to get the neck to integrate into the HD frame of the Queen's body, added to the cinching waist effect.”

To work with Alice's dramatically different scale, it was often about the eyelines. “We hoisted Alice on a platform so the eyelines would be right for her as a 8' 6” person,” Villegas explained. Another example of Alice being scaled was when she saves the Mad Hatter. According to Villegas, they used a number of platforms on the set to allow the eyelines to work properly. When she's balanced on the brim of the Mad Hatter's hat, the crew built a huge green version of that hat.

Visual-effects supervisor Sean Phillips concentrated his attention on the shots involving entirely CG characters and CG environments, many of which involved photographic elements. In the scene when the Bandersnatch attacks the tiny-sized Alice in the woods, she escapes by running among the giant mushrooms. “We had Alice running on a green treadmill,” says Phillips. “The cameras on either side are witness cameras. We had little cookies over the lights to simulate the shadows that what the mushrooms would do. Behind all of it was a matte painting, and in front of that was the deep background mushrooms, and then the Bandersnatch plate of Dave’s animation with the hair simulation and debris/dust plates. Then Alice is placed in, with more dust/debris.”

Stereographer Corey Turner touched on the difficult process of “dimensionalizing” the entire movie, for which they used several techniques. “We didn’t want to go crazy with 3D,” says Turner. “We wanted audiences to feel like part of the action.” The movie wasn't shot in 3D, Turner explained, because with the heavy use of VFX as well as the constant changes in scale, there were enough challenges on the set as it was.

“At times, the object of interest—such as the Red Queen or Cheshire Cat—got its own camera pair, which would be animated throughout the shot,” revealed Turner. “There had to be tweaks in the comps to really sell the 3D.” They also had to guard against any big depth jumps, which is what creates headaches. “We would slowly bring the audience into the depth that was coming to ease transitions,” said Turner. “And we kept Alice slightly in front of screen so that the audience would be involved with her.”

All in all, the work of creating both the VFX and the 3D version of Alice was challenging—but worth the effort. “Creatively, it was one of the best if not the best project we’ve worked on,” said Ralston, who added that Burton gave them a lot of leeway. “I found it exhilarating, and I think it shows in the work. You can feel the creative energy behind each image.”