Sony Imageworks creates an island home for birds and pigs alike in the animated feature The Angry Birds Movie
In December 2009, the world was introduced to flightless, wingless, legless (and “smileless”) birds in the mobile game Angry Birds from Rovio. The concept was simple: Players used a slingshot to launch the birds at hungry, green pigs that have poached their eggs. With colorful characters and addictive gameplay, the title became a huge hit, resulting in billions of downloads around the world.
Without question, the characters and property were highly recognizable – which can be both a blessing and a curse with fans. According to Catherine Winder, who, along with John Cohen, co-produced the movie, one of the most exciting aspects of bringing the franchise to the big screen was that so many people had a connection to the game. “Angry Birds has a 91 percent awareness around the world,” she says. “Everybody knows who these characters are, so the expectations are high. Our aspirations had to be high; we want to make sure all the fans are happy with this movie.”
To get the movie off to a flying start, Rovio created Rovio Animation, which would retain creative control over the characters and ensure that the core elements that scored big with audiences would make their way into the film. To this end, Rovio previsualized the movie and crafted the story line, and Sony Pictures Imageworks completed the remaining work. Production spanned nearly three years, and at the peak, the Imageworks crew swelled to more than 80, with 300-plus working on it at one time or another.
According to Pete Nash, senior animation supervisor, the film is filled with homages to the mobile app and uses the story structure of the game.
A Movie, with Legs
Many undoubtedly pictured a movie with limbless, ball-like characters, upon hearing about the project. Nash thinks that initial reaction provided an advantage because people had no idea what to expect. “In some cases, people may have had low expectations because they couldn’t imagine how the game could become a movie. So when you do something that is quite sophisticated, no one expects it or sees it coming,” he says. “It is a movie with very developed characters.”
According to the studio, The Angry Birds Movie is a culmination of a long-term plan to expand the game into the feature realm. Until now, Rovio made the conscious decision never to show the birds speaking or with wings and legs.
The primary challenge for Imageworks was designing characters and a world rich in detail suitable for a feature-length presentation. In this regard, the artists had to transition the cast from flat, graphic icons to fully formed characters that could be animated in three dimensions.
“The characters in the game are really simplistic. They do not walk or talk,” says Francesca Natale, character art director who designed most of the major CG cast. “The goal was to find a character that was complex but still recognizable to the audience and three billion fans.”
The film leads – Red, Chuck, Bomb, and Matilda – were the main characters at the time of the game’s launch. Red (Jason Sudeikis) is an angry bird who lives on Bird Island with the rest of the flock of large, flightless bird-like creatures. His crankiness and sarcasm are in stark contrast to the naively happy occupants of the island. Chuck (Josh Gad) is a fast talker and fast mover, which often lands him in trouble. Bomb (Danny McBride) is not the brightest bird in the flock but has good intentions. However, he has a tendency to explode when surprised, scared, or angry. Matilda (Maya Rudolph) is a New Age therapist with anger issues herself, whose anger management classes bring these misfits together.
The new friends-in-need live on Bird Island. One day a visitor arrives, a pig named Leonard (Bill Hader), and strikes up a friendship with the rest of the birds. Red does not buy the pig’s act, especially when he discovers a whole lot of little piggies hiding in Leonard’s boat. His concerns are not heeded; he is, after all, an angry bird, always pecking at something. The drift of pigs infiltrate the island, and the birds welcome their fun-loving, party presence. That is, until the pigs are caught stealing all the eggs. This does not fly with the birds, who build a raft and follow the pigs to Pig Island, a polluted, overbuilt pigsty, to reclaim their eggs.
First, though, the birds must get angry. And they do, with help from Red. They attack by air, thanks to a giant slingshot, and collect their precious cargo and head back to their island paradise a little wiser and a little angrier.
Birds of a Feather
Before modelers created Red, Natale generated nearly 100 possible designs with ink and paint. In the end, Red and his friends became more anthropomorphic. “We found a design of a bird-like creature, with the feeling of a bird,” says Natale. “The stance, the acting, and the appearance of the character all look anthropomorphic. Similarly, they don’t have actual wings; instead, they have arms that have the feel and look of wings in the silhouette and shape.”
Character modelers built the cast in Autodesk’s Maya. Rendering was done with Imageworks’ own version of Arnold (from Solid Angle, now acquired by Autodesk), and lighting was completed using The Foundry’s Katana. Compositing was accomplished in The Foundry’s Nuke.
Imageworks artists also used an in-house painting system within Maya, called KamiPaint, which is based on Autodesk’s Artisan intuitive paint and sculpting interface used by the Maya brush tools.
The birds have a rather simple design but with complex material properties – fluffy and feathery, with hair fanned out in clumps to resemble feathers. For this, the artists used an updated version of the studio’s proprietary grooming toolset called Kami, which is based on Maya and Katana. The rendering and detailing of the hair was generated in Katana, while the curve building and map painting, as well as the simulation, was done in Maya.
“These are feathered creatures, not really birds. Rovio wanted them to look soft and fluffy, which is difficult to do if you are just using feathers,” says Danny Dimian, visual effects supervisor. “They kind of resemble how birds look when they are first born: fluffy and hair-like. Huggable.”
The wings, however, are smooth and appear feathery. For consistency in the characters’ aesthetic, the entire groom is hair-based. On the wings, the hairs are lined up in a feather shape, and there is a fluffy layer of hair in between that is clumped to look like feathers. Animation controls within the groom system enabled the group to puff out the hair or flatten it down.
The Mighty Eagle, a former bird superhero that Red and his two friends seek to help them stop the pigs, is the most anatomically-based bird character in the film, though it had to look and behave similarly to the other birds. It, too, is made of hair, but the hair is lined up in geometric-looking quill shapes to resemble feathers.
In flight, Mighty Eagle’s proportions are more anatomical; when on the ground, he is more cartoony. The wings transform, becoming more anthropomorphic, like hands, when he is around the other birds. “The transition affected both the groom and the rig,” says Dimian. “We needed flexibility in the [bird] grooms as it related to the rigs. We needed more control over the grooms relative to what the rigs were doing so there wouldn’t be a lot of interpenetration. Because the birds are not anatomical, the layout was hard to plan because the animators were not limited in the range of motion.”
The judge – which was actually two characters perched atop each other, masked with a really long coat of feathers – presented a challenge, as well. “He had something like seven million hairs,” says Dimian.
The birds are incapable of flight (without the assistance of a slingshot), and move about the island on their own two feet. “The directors wanted us to think of them more like an ostrich or bird-like creature, but not a real bird,” says Nash. So here, as with the hair-feathers, the rules of reality were suspended in terms of the animation. Still, though, the animators would insert bird-like movements and mannerisms when possible – for instance, darting little head turns or an anticipatory little flutter before taking a step.
Because he is an outlier, Red had more anthropomorphic movement than the others. “Red is about four feet tall and 100 pounds,” says Nash. “In fact, none of the birds are bird size; they are huge. It is a wholly invented world. As long as we obeyed the rules of their weight, they become believable in their movement.”
The animators used an IK/FK rig for the characters; a switching system enabled them to change between the two effortlessly over a frame to achieve some complex movements. “Our rigs are very flexible, especially the facial rigs,” says Nash. “We can pull the corner of the mouth really far. We didn’t do that so much for the birds, which have beaks, but we did for the pigs. The pigs have pliable faces, so we wanted to have some form of structure on them. There was a control for every single vertex on the face that you could move if you wanted to.”
Red, as the central character, became the animators’ primary focus, and his anger played a big part in how he was brought to life. “He was the most complex character as far as personality, and the trick was to make him appealing because he is always angry,” says Nash. “If he is a jerk all the time, nobody is going to like him, and you need people to identify with the main character.” Through trial and error, the animators discovered that a little anger goes a long way, choosing an understated approach.
The animators used reference of Sudeikis performing his lines and his comedy in general. “We saw the little things he does, like when he says something that’s sarcastic, he’ll do it with a smile on his face. It’s part of his charm, his appearance. We borrowed that for Red,” Nash says.
Red, of course, has a pair of signature, thick, bushy, dark brows, which became “a major science project,” says Nash. “There was this charcoal effect on the feathers of the eyebrows. It was difficult to not have them clump and not have the hair interpenetrate. If you go from an extreme surprise pose to an extreme worry pose, that is a lot of face change, and those clumps are going to blow all over the place. It ended up becoming a complex rig.”
The bird community has roughly 130 types of birds, not counting the supporting crowds of characters. Even though the movie characters have limbs, they are still ball-like creatures, what Nash describes as “closed” characters, meaning their heads integrate into their bodies, as opposed to an “open” character that is tall and slender, with limbs. As a result, animation becomes difficult to solve at every angle – when you turn the characters around, their face distorts; when you animate their face, their body distorts.
Bomb presented a particular challenge when he would explode, which required the animators to deform his face quite frequently. Using an in-house plug-in called TweakIt, the animators could model and rig on the fly within a scene. “[TweakIt] allows you to grab a portion of the face and move it, then move the weights of the mesh,” says Nash. “We did this at a very intricate level anytime something would expand or contort a lot, like when Bomb would explode.”
While Bomb tries to control his explosions, Chuck has little, if any, self-control. “Chuck is the most pushed character in the film because his power is super-speed. Josh Gad performs him like someone with ADD – talking a mile a minute, changing his ideas mid-thought – so we tried to treat his animation that way,” says Nash. “We tried to cram as many ideas as possible into the performance as we could. We could do things like an impossible pose change without worrying about the actual mechanics of getting there. It was surprising how many ideas we ended up putting into his performance.”
Further complications resulted from the slow-motion and time-lapse sequences involving Chuck.
And then there is Matilda, who, in the beginning, is touchy-feely, always trying to be overly pleasant. “So we wanted her movement to be overly graceful, fluid, and perfect,” says Nash. “But then, because she is actually harboring a deep anger herself, you’d see a quick flash of a demonic face – snap – and then she’d be back to her extremely pleasant self in an instant.”
Some characters were trickier than others, though the bigger animation issue resulted from large, complicated shots with many characters moving all at once. “When I came on board, they showed me some early storyboards, so I knew it would be an ambitious project,” says Nash. In one sequence there are 50 to 100 pigs stealing the eggs in an orchestrated heist. “The whole movie is filled with shots like that,” he adds.
While simple in design, the pigs were one of the artists’ greater challenges. “It’s deceptively hard to get very simple things right,” says Dimian. “Francesca [Natale] and Clay [Kaytis, co-director] were very clear that they wanted the pigs to have very smooth forms, very clean shapes – and also that the pigs would have to have a very wide acting range. However, the simpler a character is, the more the audience is apt to notice every imperfection and every change in that shape,” he says. “So our characters had to transition these simple, clean shapes into crazy animation.”
This meant that the rigs had to be especially complex – underneath, they have a very complicated, sophisticated model that required a lot of technology, says Dimian. “Oftentimes the rigs focus on the range of motion and what the character can do. On the pigs, because of the volumes and deformation, each needed to have very intricate, smooth controls so all the imperfections are smoothed out. The pigs stay soft, plump, and on model as they went through some very extreme poses.”
Volume controls were incorporated into the rig with predefined ways to create the skin folds and wrinkles, rather than have them result from the performance only. Because of this, there is a puffy little volume, as opposed to flat little wrinkles, when the pigs move.
There are thousands of pigs, and they move in unison, like a hive, working for the same purpose. So, the question became whether to make them the same or different in appearance. The answer: to make them unique. “When you look at them as a mass of characters, they should move as one unit, but when you get close, each one has a very distinctive personality and a very specific role,” says Nash.
In terms of their appearance, the pigs are primarily material--based, with a subtle hair layer so they don’t look plastic-like. “They look especially good in some of the night shots where you have lighting that is rimming them and this nice fuzzy little hair layer that adds a lot of detail,” Dimian points out.
Tale of Two Islands
The movie has two very different civilizations. Most of the movie takes place on Bird Island, a lush, organic, visually rich environment that is stylized with a touch of realism. There is no electricity or machines. In contrast is Pig Island, an overbuilt, polluted, industrial-type world. Between the two islands, there are more than 90 locations that appear in the film.
According to Pete Oswald, production designer, due to the more basic design of the characters, the filmmakers took the opportunity to make the worlds more realistic and complicated. “We wanted to design a film that was familiar yet unexpected,” he says. “So, the shapes in the film are very bold and exaggerated, and some are cartoony.” Nevertheless, they are textured with real-life materials. For example, the bark of the trees have a bird-feather motif, harkening back to the fact that the birds are flightless and have never been off the island.
The artists used a terrain system called GIT when generating the foliage on Bird Island. Dimian likens it to a grooming system, whereby the artists are “grooming” the terrain, only with objects instead of hair. “It’s procedural and works like a paint system. You can paint over an area, and that populates it based on a predetermined ratio of grass and flowers,” explains Dimian.
The artists also built an extensive library of plants, trees, and shrubs, all in a bird-inspired motif, that allowed them to mix-and-match, scale, and create a rich world.
All told, there are more than 100 individual, organic components in the Bird Island library. There are 24 types of trees, a mixture of imaginative and realistic. In addition, the artists used a library of 40 to 50 plants, rocks, and other items. “We had to build more unique environments here because we didn’t want the island to look manufactured,” says Dimian. “However, making it look organic while doing it procedurally is difficult.”
A similar organic construction set library with roof types and side structures was used to build all the bird huts around the village.
In contrast is Pig Island, where there’s no rhyme or reason to how things are constructed. Buildings – more than 1,000 – are placed haphazardly and stacked vertically atop one another. “Pig Island is kind of a Rube Goldberg type of world,” says Dimian. “It is very complicated-looking and heavily instanced. But, it’s built to fall apart.”
According to Dimian, as the animators were working on the destruction sequence on Pig Island, they didn’t know for sure which part of the city they would blow up or how that would happen. So, they decided to use a simple construction set comprising small blocks with volume that could be mixed and matched to create a range of structures. “We didn’t have to worry about which pieces were going to be built specifically to be destroyed,” he explains. “When we handed this over to effects to shatter, every piece was able to break.”
The main destruction was achieved using the Houdini Bullet solver.
Many effects from both islands came from a library of pre-simulated, pre-rendered elements – plumes of smoke, layers of smoke, explosions – that lighters could pull into a scene. The water effects, meanwhile, were simulated in Houdini using varying combinations of FLIP, regular particles (POPs), Ocean Spectrum tools, and the Ripple Solver, all within Houdini. Interactive fluid splashes were mostly achieved with Houdini FLIP fluid solver.
“We didn’t want the water to look completely photoreal because it is a stylized movie. This is a make-believe place but has a touch of photorealism. The design is not real, but the materials are. But you do not want to overdo the complexity with things like water and smoke if they are to fit with more stylized characters,” says Dimian.
The foam and bubbles were generated with Houdini particles, while a FLIP splash element produced a set of fields that gave fluid-like motion to the particles. The beach-break, meanwhile, was too large for a single FLIP simulation, so it was broken up into a series of parallel sims that were surfaced together post-simulation. Only the water that was relatively close to shore was FLIP-simulated. Farther away from shore, the water transitioned to a non-interactive Ocean Spectrum surface, while foam at the water’s edge was created with POPs. The wakes and splashes from the boats were made with a FLIP sim and merged into the surrounding non-interactive Ocean Spectrum surface.
Some of the more complex water work was done for the Lake of Wisdom, where Mighty Eagle nests. The waterfalls were made with a combination of FLIP, for the waterfall proper; Ripple Solver, for the radial ripples in the various pools; and Ocean Spectrum, for ambient ripples on the main lake. Each waterfall had its own unique mist simulation, generated in Gas Solver.
A Perfect Blend
Nash and Dimian are no strangers to animated features, with both having worked on the more cartoony Cloud with a Chance of Meatballs and the more realistically animated
Surf’s Up , to name a few. “
The Angry Birds Movie is a nice blend between the two extremes,” Nash says.
Without a doubt, Sony Pictures Imageworks and Rovio Animation are putting a lot of eggs into this property’s basket, transforming these popular, beloved characters for their big-screen debut. Will feathers fly, or will the movie make avid (angry) bird-watchers of us all?
Karen Moltenbrey is the chief editor of Computer Graphics World.