Issue: Volume: 24 Issue: 7 (July 2001)

Staying Tooned

By Barbara Robertson

At first glance, the animated feature Atlantis: The Lost Empire looks like a traditional cel animation from Disney. As those who have seen the movie can attest, however, this film breaks with the past in a number of interesting ways. For example, there are no song and dance numbers and no cute talking animals. But what most moviegoers won't know is that even though the film looks like cel animation, it has more 3D elements in more shots than any "traditional" animation created at Disney Feature Animation before it.

Set around 1914, Atlantis follows the adventures of a scholarly linguist and cartographer named Milo who joins an expedition bent on finding the lost kingdom of Atlantis. Also along for the ride are an intriguing and often hilarious assortment of other explorers: a cunning, square-jawed commander and his femme fatale lieutenant, a wry chain-smoking woman "of a certain age" who is the team's world-weary communications officer, a spunky Latina mechanic, a crusty chuck wagon cook, an eccentric geologist nicknamed the "mole," a wisecracking demolitions expert, and a fast-talking medic. Produced by Don Hahn and directed by Kirk Wise and Gary Trousdale, the trio also responsible for Disney's Beauty and the Beast (1991) and The Hunchback of Notre Dame (1996), Atlantis opened in the US on June 15.

With this film, Disney's classic fairy-tale journey to fantasyland has been replaced with a wild ride to adventure land, and as befits a tale hell-bent for 20,000 leagues under the sea, the design is bold and edgy. In most Disney animations, flat-shaded characters perform over lush, painterly backgrounds. By contrast, both the backgrounds and characters in Atlantis were created in the same flat, graphic style. "From the original concept, we wanted this big action-adventure movie to look like a comic book," says Trousdale.
All the vehicles in Atlantis are 3D models unless they're far in the background. The backgrounds and effects in this shot are 2D elements that were created traditionally.

To help achieve that look, the directors enlisted the help of artist Mike Mignola, known for his Hellboy comics, as a production designer. Art director Dave Goetz incorporated the look of World War I recruiting posters, which have hard divisions between light and dark, into the style. And for the backgrounds, the team was inspired by paintings from Ed Mell, an artist who paints desert landscapes of the American Southwest. "He uses colors almost like cut paper, using gradations of color on top of each other rather than rounding and shading to create a form," says Trousdale.

With such a simplified graphic look, why did the studio choose to use 3D graphics techniques for much of the film? "We knew going into it that computer graphics were going to play a large part," says Wise. "We knew it was an adventure story that took place underground and that the characters would encounter monsters and flying machines and vehicles from the time period."

Adds Trousdale, "It made our lives a lot easier to do a giant digger with all of its tank treads and wheels [in 3D], rather than having some poor animator with a T-square trying to draw those things for the rest of his career and natural life."

Chris Jenkins, artistic director, also points to a technical reason to have line-intensive elements such as vehicles and complex monsters created in 3D rather than drawn by hand. "You really need the technical exactness of three-dimensional control," says Jenkins. "When you have tiny pencil lines lying close together, and they aren't exactly the right width and distance apart, you get boiling, which is a jittery movement."
The star, Milo (left), is always hand drawn. The film's comic-book style, with hard divisions between dark and light, helped the 3D rendering team match the 2D elements.

Thus, the computer graphics team had to devise techniques that would make the many 3D elements look hand drawn for this comic-book style movie. "Companies like ILM integrate all their 3D work into a live-action world, sometimes flawlessly," says Moe Merell, lead digital character animator. "Our job is to integrate 3D into a 2D world."

The integration of 3D into the 2D world had to happen behind the screen as well. At Disney, the process of making animated films has changed little since Fantasia. Even Disney's digital compositing and production system, CAPS, was designed by Pixar under Disney's direction to complement the existing process, not change it. The advantage that CAPS gave Disney was the ability to manage and manipulate more layers than was possible with optical systems, and to track and organize all the pieces of the complex process. These days, storyboards and layouts, characters, and effects are still drawn by hand, though now they're scanned into the computer. Similarly, backgrounds are painted traditionally and scanned into the computer (or sometimes painted using computer software). The scanned hand-drawn characters are painted digitally in the ink and paint department, and then all these elements are combined in the color modeling department, where other colors are added and adjusted by artists. Finally, the digital cels go through a rigorous quality checking process.

Because Atlantis includes so many 3D elements sprinkled throughout the entire film, it was especially important that the 3D process fit within this traditional process throughout the production.

As close as [Kirk and I] are to Beauty and the Beast, it's obvious to us and probably to everybody else that when you open the door to the ballroom, you're in 3D land and when you go back out you're in cartoon land. It worked fine. Nobody complained," says Trousdale. "But in Atlantis, we wanted to make the distinction a lot less obvious."

Unlike previous Disney cel animations, Atlantis is more of a hybrid: The 3D elements are in most scenes, not largely contained in one sequence. "[Atlantis] is a little different from past Disney traditional movies in the sense that in Lion King we did the stampede, in Hunchback, we did the crowd, and in Hercules, we did the Hydra," says Kiran Joshi, digital production department head, who has been working with 3D graphics at Disney since Beauty and the Beast. "This was the first time [the studio] wanted to make a hybrid movie."
The light beams on the 3D vehicles (left) are 2D effects. The submarine (below) is a 3D element, as are all the people and vehicles getting ready to board.

Feature animations at Disney are measured in feet, not frames. Some 3500 of this film's 7500 feet passed through a 3D pipeline at some point in the process. Only two sequences in Atlantis have no 3D elements.

One large wall of Joshi's office is papered with colorful images that make the extent of the 3D work immediately obvious. As digital production department head, Joshi led the group responsible for all the 3D elements in the movie. (At Disney, "digital" means 3D.) On his wall, the sequences are listed in vertical columns and extending out from all but two are horizontal rows of stills from the movie, each representing a 3D element-digital people, stone giants, intricate cars, fish-like vehicles, a submarine, the monster, Milo's book, fireflies, lightning-like effects, a convoy of trucks, and many more. Nearly all the elements were created and animated with Alias|Wavefront's Maya, although the team also used Side Effects Software's Houdini for a few effects. The pictures on Joshi's wall display the result of four years of the group's work.

"Digital production used to get involved after the story was all done and planned. They'd say, 'Oh, we'd like the stampede in Lion King to be 3D," says Joshi. "I've always felt like we needed to be involved earlier than that. We wanted to be able to say to the director, 'if you're trying to do that in your story, maybe we can give you this kind of effect.'" With this movie, they were able to do just that. Joshi and Merell, who had both worked on the 3D team for Hunchback, were involved in the Atlantis production from the beginning, in January 1997. "We helped the directors understand what, why, and how 3D elements could be an integrated part of the story, not just a cool effect," Merell says.

With 100 moving parts and tattoos on its shell, the football field-sized monster called "Leviathan" was a perfect candidate for the 3D graphics group. "This thing had shells, and bottom legs and a tail and tentacles that would all move, and big crab-like arms that we could move like pistons," says Merell. "It was my baby for years."

Merell created early models for the Leviathan; Paul Seidman created the final models and the character animation rig-the skeleton and controls-for animating the Leviathan, in Maya. He kept the monster alive, as Merell puts it, during the production. "A lot of times the rig had to be adapted on a per shot basis because there were so many things that had to mesh correctly," says Merell.

To animate the character, the team borrowed techniques learned from cel animators. "We're integrating more of the way traditional animators do things into the 3D world now," says Merell. He explains, for example, that 3D animators will often set key poses in Maya and let the program create the in-between animation. "If you do that, you get floaty animation," he says. "By breaking down the poses in between the poses, and then varying speeds, keeping in mind the weight and the acting of the character, the animation looks better. In some of the scenes, we're animating every frame. It's crazy. And it's exactly like traditional animation."
The backgrounds for these shots were painted digitally; the Leviathan creature, the main submarine, and the mini-subs are all 3D models. The 3D team rendered tens of thousands of layers to create individual pieces of art for the lines, tones, paint, and s

In the traditional process, all the 2D artwork is scanned into CAPS, where effects animators can view it as overlays or underlays-that is, in front of or behind characters. The 3D animators could look at the same 2D artwork in Maya. "We basically create Maya scenes with all that imagery as backgrounds for the [3D] animators," says Marcus Hobbs, look development and lighting supervisor, who helped build bridges between Maya and CAPS so that 3D animators could see the 2D layouts and characters frame by frame when they wanted.

"In one shot, for instance, the Leviathan swims past the submarine. Inside, you can see Commander Rourke reacting to him," says Merell. Because animators working in Maya could see, in the 2D art, where Rourke was looking, they could correctly position the Leviathan to give the impression that Rourke was reacting to the monster swimming past.

The 3D team also customized Maya to help the animators. Because character and effects animators often needed to work in parallel, and because the scenes often contained multiple 3D elements, the team made it easy for animators to switch from low res to high res and to swap animations from one file to another. In addition, the team created "foolproof" interfaces with specific control knobs and buttons for each element in Maya. "We didn't want one person rotating the propellers of the submarine anti-clockwise and another clockwise, so we locked them in one direction," Joshi says.
Hand-drawn effects enhance a 3D sub's destruction.

Joshi is describing only one of three submarines that were built in 3D. When the Leviathan blows up the main submarine, three smaller pods, one of which contains the hero characters, escape and are guarded by several "mini-pods." Ultimately, only one pod survives. Inside are the main characters and several vehicles-the digger, a command car, a field truck, the cook's wagon, and a troop truck (with generic digital soldiers), among others. "One of the things we realized is that when you build vehicles, you'd better build drivers because no one wanted to draw them," Joshi says. Similarly, the team also created Atlantean warriors to ride in their 3D vehicles, which took the form of sea creatures such as hammerhead sharks.

The vehicles were obvious elements to hand to the 3D department. Less obvious was the use of Deep Canvas and the effects. Deep Canvas, first used to create the 3D jungle that Tarzan surfed through, gives background painters a template for painting scenes that accommodate a camera moving through 3D space. It was used for a handful of shots in Atlantis-notably, to allow the camera to follow the action as characters and vehicles moved through lava tubes and tunnels.

As for the effects-"Effects that are very complex but look bold became good candidates to do in 3D, but things that were just big bold shapes were traditionally hand drawn," says Marlon West, effects supervisor.
The effects team would use Maya and also hand draw effects on paper. In this scene, the fireflies are 3D, but the fire is hand-drawn.

For example, in one sequence, Milo, a hand-drawn character, was chased through lava tubes that lead to Atlantis. Background painters using Deep Canvas software painted the tubes; however, the lava following Milo through the tubes was drawn by hand in the effects department. "It's drawn in the traditional way we've been doing things since Fantasia," says director Wise.

Most of the particle effects were created in Maya, although one effect, a laser zap, was a blend. For this, a path was hand drawn, particles were driven along the path, and the result was enhanced with Nothing Real's Shake. "It's a 3D effect, but the path is just a 2D path on an image plane," Hobbs says.

One of the most complex effects created in 3D was the "crystal," the power source for Atlantis, which looks like a tube of light surrounded by rotating stone shields. "It has layers and layers," says effects supervisor West. "There are three levels of membranes playing against one another, and they're all different colors, with a kind of crackly energy, and they emit a three-dimensional kind of light. When you start laying all those levels together, it becomes impossible to do traditionally."

On the other hand, effects around the 3D elements were often hand drawn to help integrate them with 2D elements and characters. The Le viathan shoots hand-drawn rays, the convoy of trucks kicks up hand-drawn dust. When the digger bored into a wall, the rocks thrown off the wall were drawn by hand, the sparks were both 2D and 3D, and the flashes from the sparks were 2D.
The rotating stone shields and glowing energy inside are 3D elements.

Four of the 38 effects artists worked exclusively with 3D effects; six moved between 2D and 3D. West, for example, has an SGI workstation on one side of his office and a drawing board, which looks a little like a light table, on the other. "We did the scene with the digger that way," he says. "We animated the digger in Maya, plotted it out, and then drew traditional effects on top." The 3D elements were plotted onto paper with registration holes so that the plot could be accurately placed on the light table for the hand drawings, which were created on another sheet of paper placed on top. "I'm an effects animator and our shows typically don't have many digital elements," he says. "It was a high learning curve, but it was a lot of fun. I'm much more willing to reach for 3D solutions to things now."

As far as the art directors and directors were concerned, however, all the elements looked like 2D elements. "We gave them several levels of artwork per element and they treated it like they would have treated anything else," says Hobbs.

Hobbs explains, for example, that a close-up of a hand-drawn character would go to the color modeling department as several layers-one for lines, another for shadows, another for reflections in his eyes, and so forth. "The reason they do that is for artistic control," says Hobbs. "There are an average of 1500 to 1700 shots in an animated feature and someone is sitting there shot by shot making sure all the colors transition and contrast in ways that help the story and keep the audience interested. They aren't rolling film and looking at dailies, they're looking at still images. They want every frame to be perfect."
Because of its complexity, the crystal energy surrounding the hand-drawn Princess Kida is a multi-layered 3D effect.

By providing similar layers for the 3D elements, the digital team gave the art directors the same control over color and opacity that they had over the traditional elements, and thus helped make the integration of the two types of elements more likely to be seamless.

To accomplish this, each 3D frame was rendered using three renderers, which produced from five to 13 pieces or levels of artwork: Disney's proprietary Inka system put lines around the 3D models, Maya's renderer handled the lighting, and Pixar's RenderMan rendered the rest of the layers, usually about 85 to 90 percent of the total, according to Hobbs. The submarine, for example had four line layers, two shadow or tone layers, a paint layer, and several more layers for details such as gun turrets, window mattes, and grunge.

In terms of technique, Hobbs found the graphic style for Atlantis easy to work with. Shaders were relatively simple because most of the detail on the 3D models was painted in Alias|Wavefront's Studio Paint and applied as a texture map. The design also helped with lighting. On previous films, Hobbs explains, there was a fall-off, a transition, between dark and light on the 3D elements, and although the 2D elements also had a fall-off, he felt that the two often didn't match. The comic-book style of Atlantis eliminated the fall-off completely. The tricky part for Hobbs, though, was in creating the tones. "When an effects animator draws a tone on a character by hand, he draws line artwork that he fills in with his pencil," he says. "The [tones are] supposed to be shadows, but the artists aren't limited by what happens naturally, they just draw for the aesthetic, and they make beautiful shapes and designs. That's how we had to make our 3D tone renders look-like someone drew them."

The shadow shapes were created by the 3D team using lights in Maya and then rendered in black and white-black for tone, white for no tone. The layers were sent to the color modeling department along with the rest of the artwork for a shot to be composited and colored.
Background painters used Disney's Deep Canvas to accommodate a camera moving through the scene below.

"I counted 50,000 pieces of art in a long shot of the submarine dropping into the water," Hobbs says. Shots with convoys of dozens of vehicles, each with several layers of artwork, also produced thousands of pieces of art. To render those thousands of layers, the team uses a distributed render cube. "We have a little dedicated renderfarm and a lot of desktops," Hobbs explains. Thus, making sure that all the pieces got rendered and accounted for became a management issue. No one questions whether it was worth it.

Joshi has watched the 3D department at Disney change from a small, isolated group that created somewhat isolated parts of movies into a group that is more a part of an overall process. "I think a lot of people who worked in digital felt that with this movie we were really part of making the movie, we weren't just making images," he says. In addition, more traditional artists, such as background painters and effects animators, are using the 3D tools and discovering the benefits.

"It's been a slow evolution. But I think the two worlds are coming closer," Joshi says and laughs, "I keep saying the day that this will be completely homogeneously integrated will be when everyone is familiar with everything and they don't need a guy like me."

Barbara Robertson is Senior Editor, West Coast for Computer Graphics World.