Devilish Effects

Abe Sapien: Behind this door... ancient evil.
Hellboy: Oh, well. Better let me go in and say, "Hi."

In case you're not a fan of Mike Mignola's comic books, Hellboy was a Nazi experiment gone good; a red demon baby conjured up at the end of World War II by Hitler's occult scientists and rescued by US soldiers. He grew up to become an evil-fighting member of the US Bureau of Paranormal Research and Defense (BPRD) and a comic book cult favorite. Now, thanks to Sony Pictures Entertainment, moviegoers in the US will discover Hellboy's wry humor when Hellboy, the movie, opens April 2. Directed by Guillermo del Toro of Blade II fame, the science-fiction action-adventure stars Ron Perlman as Hellboy, Doug Jones as fellow BPRD investigator Abe Sapien (with David Hyde Pierce providing the fishy humanoid's voice), and Selma Blair as the fiery Liz Sherman.

Providing much of the action, some of the creatures, and a touch of comic book flair were 850 visual effects shots created by an assortment of studios—including Tippett Studios, which handled such major effects as the digital creatures, and The Orphanage, which completed 250 shots that showcased its skill with digital doubles, particle simulations, fluid simulations, atmospherics, and hard surface models, such as cars. Additional effects were created by freelancers and other studios. "We got good deals, and everyone is very happy with the work," says Ed Irastorza, former visual effects producer at Tippett for Blade II, who took on the dual task of visual effects producer and supervisor for Hellboy.

Work on the film began when Irastorza and Blair Clark, visual effects supervisor at Tippett Studios, met with del Toro to begin planning Hellboy even before the project was approved. Once Tippett was officially on board, the studio began developing previzualizations and animatics. When filming began, Clark joined the crew in Prague, where he photographed actors for reference, shot backgrounds for texture painters, and supervised data collection for scenes into which the studio would later add digital characters.

Except when Hellboy appears in extreme stunts, he is portrayed by Perlman or a stuntman wearing red makeup, stubby horns, and a prosthetic "right arm of doom" created by creature designer and make-up artist Rick Baker. His devilish tail is sometimes a prosthetic, sometimes digital. But when the stunts are too dangerous or humanly impossible, he's all digital. "Hellboy is a monster who makes fierce, aggressive moves, so he was really fun to animate," says Todd Labonte, animation supervisor at Tippett, who made a digital Hellboy crash backwards through a window, among other scenes.

To help studios that had the devilish double in their shots match the real Hellboy, Irastorza took photos of Perlman in costume and makeup on set during filming in Prague. "We'd photograph him over and over in different makeup (for example, if he had blood on his hands) and different costumes in 360-degree rotations against an 8- by 5-foot white-board grid with one-inch squares," says Irastorza." Ron got a little sick of it, but it gave everyone photographs for texture mapping."

Three members of the Bureau of Paranormal Research and Defense—Hellboy (Ron Perlman) and Liz Sherman (Selma Blair), above, and Abe Sapien (Doug Jones), at right—fight evil in the film Hellboy. Digital doubles for Hellboy and Abe Sapien

Tippett Studios also created and animated a digital double for the character Abe Sapien so that the creature could swim underwater. "We filmed a tank of water, added CG matter, put reflections on the glass, and added CG elements in the water to create the environment," says Clark. "When Abe is swimming underwater, he's digital." When Abe is out of the water, however, actor Doug Jones wears a suit and headpiece created at Spectral Motion that was altered, digitally, at Eden FX. "The suit didn't have a way to blink its eyes, so we added horizontal and vertical blinks and also modified his brows and cheeks to give him expression," says John Gross, visual effects supervisor.

Animator John Teska worked in NewTek's LightWave to do the shots and create a transformation scene for Hellboy that included igniting the demonic right hand of doom. "We used particles in LightWave that we output in six or seven passes," he says.

The majority of character work for the show focused on Sammael, a leonine creature with a Medusa-like head that was sometimes played by a stuntman wearing an animatronic suit and was sometimes a CG character created at Tippett. Using a maquette from Spectral Design, which created the animatronics, Tippett fashioned a digital model capable of handling the creature's unnatural movements. "Every joint was supposed to twist 180 or 360 degrees at any time," says Paul Thuriot, CG supervisor. "Computers don't like doing such things."

Working with fellow CG supervisor Todd Stinson, the two developed a muscle and skin system that worked within Alias Systems' Maya. "It's a layer-based system," Thuriot says. "Muscles are built on top of a skeleton structure with skin on top and a fat layer in between." The muscles, which are connected to bones or other muscles, are tube-like NURBS objects that can preserve volume. The fat is all math. When an animator moves the bones, the muscles move the fat, and the skin slides over the muscle and fat layers.

Tippett Studios developed a new muscle and skin system for the CG version of the evil Sammael and rigged the character so that its joints could twist unnaturally.

In real life, of course, muscles move bones, not the other way around, so Thuriot built a Mel tool that triggers the muscle and skin movement before the bones are moved. To accomplish this piece of magic, an animator first created the performance, determined which muscles to trigger, and then, essentially pushed a button. The simulation happened later. "The tool walks through the animation, looks at keyframe poses, and based on how much the muscle will deform, triggers the muscle a few frames ahead," says Thuriot. "The skin rides along. It's one of those subtle things that you notice only if it isn't there."

To move the skin, Stinson developed a system that worked something like a cloth solver. "With a cloth solver, all the vertices are connected and we apply forces to them," he says. "For the skin, we connect all the points in the skin individually to muscles or perhaps bone underneath with Newtonian spring forces." As the muscles moved, the fat layer tried to preserve the distance between the skin and the muscle, and all this action moved the spring forces connected to the skin points—in fact, some 15,000 in all for Sammael—thereby pulling the skin.

"One of the things our skin tool does that's unique is to run in static or dynamic mode," Stinson says. "In dynamic mode, like a cloth solver, the position of the skin in frame 105 depends on the position and velocity of frame 104." So, when a character punches a wall, we see a jiggle roll up its skin. To carry this out, the simulation had to run sequentially on one machine, which caused long render times. Thus, Stinson developed a method to render skin points using information based on overall geometry instead. Because this information could be derived on a per-frame basis, the frames could be solved in parallel on many different machines. "The only thing we can't get from the static solver is momentum jiggle," he says. "Otherwise, the skin movement is pretty similar to the dynamic solve."

In addition to Sammael's flexibility, his 18 strands of "hair" caused animation angst. "It was hard to match the servo controls on the animatronic head," says Labonte, "so we often used dynamics." Sammael's body was hand-animated, though, by Labonte's crew, which used videos of silverbacked gorillas and lions as reference.

One of Sammael's most annoying characteristics is that when he's killed, he's reborn as two Sammaels. In fact, in a Grotto scene, Tippett supplied animated Sammael embryos. During this sequence, in which several Sammaels fight a sometimes digital Hellboy, compositors controlled the camera moves in the plate by using a plug-in for Apple's Shake called Twixtor (RE:Vision Effects), to make the shots more dynamic.

The real compositing challenge, however, was having all the CG characters interact properly with water around their feet. "We used a tool that can warp the water in the 2D plate based on the 3D animation," says Colin Epstein, a lead compositor. "And then we added 2D elements and 3D bubbles, foam, and splashes that were generated procedurally by the effects team. There's a lot of blending between real and CG." Lighting and rendering efforts were led by technical directors Kirsten Drummond and Steve Reding who used Maya and Pixar's RenderMan to match the on-set lighting effects.

In another effects-laden sequence, a long chase and fight between Hellboy and Sammael, the characters fight around a train and on a city street. Sometimes they're real; sometimes they're digital. In one scene, for example, only the tracks were real. Tippett added the characters and the background.

During some of the street scenes, the crew at Tippett added Sammael to plates that had been altered by The Orphanage. "The sequence was filmed on streets in Prague," says Clark, "so, of course, all the cars had to be changed."

Supervised by Shadi Almassizadeh, The Orphanage created five different types of cars, plus a truck and motorcycle, for the street scenes, making sure that highlights streaked properly in the fast-moving shots. Often during this sequence The Orphanage's digital cars and trucks were added in the foreground to mask camera equipment and the film crew behind.

The Orphanage also created 17 digital doubles, a bridge sequence, and a dramatic sequence near the beginning. "Hellboy and the BPRD team are looking for Rasputin in this vast unending underground area when suddenly a pendulum shatters part of a bridge that Hellboy's on," says Irastorza. "The Orphanage built the digital environment that surrounds the bridge. It turned out to be one of the best shots in the film."

The Orphanage created a five-million polygon set to allow the virtual camera to move freely, and used rigid body dynamics to break apart the CG bridge. Hellboy is running on a bluescreen set until the end, when he becomes digital.

Supervised by Ryan Tudhope, the 71-shot sequence included a rigid-body simulation for the end of the bridge that breaks apart as Hellboy runs. "We used the Reactor plug-in in Discreet's 3ds max, exported the scenes to Maya for the digital-double work, brought them back into max and then rendered the shots in Splutterfish's Brazil," he says. For compositing, the team used Adobe's After Effects and for shots that depended on particles, SiTex Graphics' Air, a RenderMan-compliant renderer.

For the so-called "Abbey Ruins" scene early in the film, sequence supervisor Matt Hendershot used Maya fluids controlled with particles to create a globe-like gateway to hell, and rendered the result in Maya. Kevin Baillie, CG supervisor, added digital rain and lightning.

The Orphanage crew also created CG tails for Hellboy, built the exterior of Ballamy Hospital, managed full CG shots of a creature imprisoned in a crystalline tube at the end of the film, and helped surround Liz Sherman's transparent hand with blue fire. "It was fun to have such a wide variety of work," says Tudhope. "The company as a whole learned from this project."

When Liz Sherman completely turns to fire, the effect was created by Café FX, which used Maya fluid simulations to engulf her body in blue flames. "Scott Gordon and Victor Grant also created an effect that shows her glowing from within," says Everett Burrell, effects supervisor. "We used Maya for the animation and the match moving, but for the shockwave that happens after, we switched to some LightWave tricks using the plug-ins." All the shots except those of the fire were rendered in LightWave; the fire was rendered in Maya.

Of all the effects in the film, the work that's least likely to be noticed is that from Hatch FX, which created 80 percent of the matte paintings and the establishing shots, according to Deak Ferrand, founder and artist. Interestingly, Ferrand has begun using miniatures for his matte painting work. "For the ice cave scene, we started by building a resin model of a translucent ice cave that we could light from behind," Ferrand says. "That's what we're doing a lot of now—building miniatures, taking photos of the miniatures, painting on the photos in PhotoShop, and then projecting the result back onto 3D models." The result is a 2-1/2D matte painting that accommodates a camera move. For the 3D geometry texture projection, Hatch uses Softimage XSI.

Hatch FX created matte paintings for background and establishing shots such as these by starting with photos of models created at the studio that were scanned, painted, and projected onto simple 3D geometry.

For one shot, the studio photographed miniature clouds built out of pillow fillers. "We projected the photos onto simple geometry shaped like a cone so it looks like the camera flies through a storm," Hatch says. "We must have used 50 or 60 layers of photos into which we mixed XSI particles for transitions. There are no rules in matte painting any more. The only thing that counts is that it looks real at the end."

If the enthusiasm for the project shown by the effects crews is any indication, many of whom are Hellboy fans, the movie will be a success and Hellboy will move from cult status to the mainstream. If it doesn't, it will at the least have given the crews in these studios a chance to work on a project starring a favorite superhero and will have provided many studios the chance to showcase new skills.

Barbara Robertson is a contributing editor forComputer Graphics Worldand freelance journalist specializing in computer graphics, visual effects, and animation. She can be reached at BarbaraRR@comcast.net.

Adobe Systems www.adobe.com
Alias Systems www.alias.com
Apple www.apple.com
Discreet www.discreet.com
Eyeon Software www.eyeonline.com
NewTek www.newtek.com
Pixar www.pixar.com
RE:Vision Effects www.revisionfx.com
SiTex Graphics www.sitexgraphics.com
Splutterfish www.splutterfish.com