Zombie Tsunami
Issue: Volume 36 Issue 5: (July/August 2013)

Zombie Tsunami

Although folklore is rift with tales of the undead, the modern zombies in cinema owe their genesis to Director George A. Romero, who crossed a zombie with a vampire to create a new kind of horrific, flesh-eating monster for the 1968 film Night of the Living Dead. The zombies in that film and many since were ghoulish creatures, often slow moving, mindless, decaying corpses that shamble toward their victims. Over time, the zombie rigor mortis has softened a bit, allowing evil creatures to move in more human ways, sometimes even greater than human. And then there are the zombies of Paramount Pictures’ World War Z, directed by Marc Forster.

“These are not slow, Night of the Living Dead zombies,” says Oscar winner Scott Farrar of Industrial Light & Magic, who joined the ongoing production in December 2012 as overall visual effects supervisor. World War Z’s zombies are lightning-quick creatures with absolutely no sense of self-preservation.

The opposite is true of the trouble-plagued production. The filmmakers rewrote and re-shot the entire third act. The cinematographer and visual effects supervisor changed midstream. Yet, the production crew managed to not only persevere, but also create what Hollywood Reporter reviewer Todd McCarthy calls “an immersive apocalyptic spectacle that tosses the viewer into the deep end of a global zombie uprising and doesn’t let up until close to the end.” Brad Pitt, who also produced the film, stars as the man who saves the day. Mireille Enos is his wife. Artists at Cinesite and The Moving Picture Company (MPC) created the zombies, with Halon handling previs and Prime Focus World, the 3D stereo conversion. Legacy Effects provided character design and makeup effects.

MPC ARTISTS moved swarms of climbing zombies using the studios Alice system and rigid-body dynamics.

MPC ARTISTS moved swarms of climbing zombies using the studio’s Alice system and rigid-body dynamics.

Zombie Choreography

Andy Jones, who won an Oscar for directing animation in Avatar, and received an Oscar nomination for supervising animation on I, Robot, had the unique role of overall animation consultant. “Paramount hired me,” he says. “I wasn’t at a facility. This happens all the time with visual effects supervisors, but I haven’t heard of it much for animation supervisors. The reason Marc [Forster] persuaded them to have me involved was so I could stay focused on the zombie performances. Any time a zombie was on set, I was there. I was like another choreographer, suggesting how we could tweak the performances digitally if we needed to, for example.”

Jones began working with Forster before pre-production to help design how the zombies – whether live action or digital – would behave. “We hired Alex Reyholds, a choreographer,” Jones says. “She specializes in contemporary dance and had a pool of movement artists and dancers who helped sculpt preferred actions. How the zombies moved. How they transition in eight or 10 seconds from a human that’s bitten into a zombie.”

London-based contemporary dancer Ryan Perkins provided much of the hero zombie performances. “He did amazing moves,” Jones says. “Marc loved it. So, I shot a bunch of tests with him and figured out different actions for different situations.”

The team also motion-captured Perkins and stunt performers to have a library of zombie actions. “We even figured out a bite attack,” Jones says. “It was like an attack dog trained to lunge, teeth first, and latch onto its prey. If a zombie’s body swung around and hit a tree, it didn’t matter. They had no sense of self-preservation. They don’t feel pain. If their prey is on the other side of an obstacle and the first zombie bashes into the obstacle, the next one will climb on that one until they have a pile of bodies that can get over the obstacle. Achieving that in CG was very difficult.”

Each zombie was once a human, though, and distinguishing characters in the early stages of zombification from humans was a particular goal for the filmmakers, who wanted the movie to have a PG-13 rating. If the zombies recently had bitten a human, the freshly infected human might be an actor in makeup. The zombies then go through a second stage in which practical makeup could still handle the zombification, albeit with digital augmentation. They might look a little like a person, but at this stage, they start to act like zombies. They want to bite people. And, that created a small problem.

“The animation was so good, producers and filmmakers thought people might mistake the zombies as real people,” Farrar says. “They wanted to make sure the audience knew the soldiers were firing at zombies, not people. So, we had to ride a fine line. But Andy had really thought through the behaviors. The zombies are twitchy. Their muscles don’t always fire exactly right. They look slightly strange without looking bad.”

Cinesite had shots with the zombies during a nighttime sequence in Korea. “They had a tremendous close-up of a woman who gets bitten,” Farrar says. “The zombie is looking for a fresh human. She sees someone driving. They have no regard for personal safety, so she launches against the windshield and bashes her face. We have a close-up of her filling the frame, and her hair and clothing look tremendous. She’s biting the actor, and you can’t tell she’s a zombie. Cinesite also did a big plaza shot with dozens of zombies running toward real people across the way. And, they handled all the shots that take place in Glasgow. But, I’d say we spent the bulk of our time with MPC on their crowd zombies in Israel. They were really good.”

Piling On

Concept Artist Kevin Jenkins created drawings with piles of zombies in various configurations that provided the basis for zombie apocalypse shots with thousands of zombies.

“We received concept work early on that showed the crowds forming into pyramid and tentacle shapes,” says Jessica Norman, visual effects supervisor at MPC. Norman, who had been a digital effects supervisor on the final Harry Potter films and a visual effects supervisor on Watchmen, moved into the supervisory role when MPC’s Adam Valdez joined the studio’s Maleficent production. MPC uses its proprietary software Alice for crowd control.

“We’d typically have 5,000 agents in the crowds, and on top of that, some specific animation,” Norman says. The agents began as 24 different body types, then, by swapping various textures and pieces of clothing, the team produced a cast of 2,000 male and female characters. “We built them as humans and with three levels of zombification,” she adds. “The first level is when they’ve been bitten. In the third level, they are emaciated. They’ve lost their hair and have torn clothing. In addition, to render the big crowds, we built four levels of detail. They weren’t heroes, but they filled the frame in motion.”

Once they had fed the characters through the crowd system, the crew worked out how big the zombies were in frame and how much resolution to apply to each one. “Usually in a crowd shot, we have far away, mid-ground, and close,” Norman says. “But for this film, we had to split the level of detail in a more creative way. In the street tumbling scene, a zombie would start way in the back and be right in front of the camera at the end, so it was high resolution all the way through.” During one sequence in the film, the zombies attack a tall wall that Israelis have built to keep the creatures out. “The zombies are attracted by sound,” Farrar says. “Unfortunately, the Israelis are so happy the wall they built is protecting them that they start rejoicing and singing. And that attracts the zombies. They climb on one another to get in there. We have shots that are 100 percent CG, and they look darn good.”

Working from geometry in shapes akin to those in the concept art, the crew at MPC used its Alice crowd-simulation software to fill the shapes for shots such as that with moving, CG zombies. For the Israeli shots, the environment artists at MPC built a 70-foot-tall CG wall. As the Zombies crash into the wall, pile up, and climb on each other to breach the wall, they form a pyramidal shape.

“Alice picks up motion-capture clips that corresponded to the inclination in various parts of the pyramid,” Norman says. “For the motion clips, we captured people on ramps and climbing on nets. If a particular zombie needed extra attention, we could render it separately and then make it part of the crowd again.”

Crowd systems typically use avoidance to keep the agents – that is, the individual characters – from running into each other. Avoidance is impossible, though, when 5000 agents pile on each other and climb without regard to self-preservation.

“We used Papi, which is our rigid-body dynamics solver,” Norman says. “Part of an agent could become a rag doll and collide with another. The zombies could interact with each other in that way. These characters are driven by trying to get to the prey. The essence of these shots is that the agents are almost impossibly in the same space as other agents. Humans wouldn’t do that sort of thing. You don’t want them to be like ants, but in a way, you do.”

Papi also helped animators create vignettes in various parts of the evolving pyramid. “We’d combine a performance with Papi so that when a zombie falls, we have gravity and tumbling as realistic as possible,” Norman says.

Mixing It Up

For shots in which the zombies are closer to their original human form, the artists augmented the live-action performances. “We added veins and scars,” Norman says. “And we did hero animation for digital-double takeovers, when CG zombies attack live-action actors.”

Farrar’s strategy was to use live-action actors whenever possible. “I wanted to intermingle CG characters with actors because it creates more of an illusion,” he says. “The audience doesn’t know what it is seeing. We shot the actors and also blank plates, so if the actors didn’t look right, we could use animated characters.”

After a year of creating zombies, the filmmakers looked back on the early work and decided to tweak it. “Some shots were in play for more than a year,” Farrar says. “So, there was a learning curve. We went through a tremendous amount of work to make the clothing colors look decent. In certain looks in the DI, for example, light blue went aquamarine, which was too punchy for the sequence.”

MPC artists created shots in Israel, such as this one with a digital airplane and thousands of CG zombies.

MPC artists created shots in Israel, such as this one with a digital airplane and thousands of CG zombies.

Also, the visual effects artists had to redo shots to achieve the coveted PG-13 rating. “We’re shooting and killing zombies, but we didn’t want to have red blood,” Farrar says. “So we made it black or more of a dust hit, or, we’d have a smoke cloud come off the body. The sheer intensity of the story drove the film toward an R rating. So, there was a lot of back and forth.”

At the end, though, the filmmakers achieved the PG-13 rating, and, from all accounts, despite the changes along the way – or, perhaps because of them – created what Variety film critic Scott Foundas calls, a “sleekly crafted, often nail-biting tale of global zombiepocalypse [that] clicks on both visceral and emotional levels, resulting in an unusually serious-minded summer entertainment.”

“I want to stress,” Farrar says, “that everyone focused on doing whatever they could to make sure the movie worked. You hear that all the time. But, there was a lot of care and attention on everyone’s part to make the sequences look as good as possible. Having the lead actor [Brad Pitt] as a producer was of value. But on every level, the creatives, the crew, the producers, and the studio folks, everyone’s goal was to make a good film. It was a combined effort. That’s rare. And, it paid off.”

Barbara Robertson is an award-winning writer and a contributing editor for CGW. She can be reached at BarbaraRR@comcast.net.