Game developer Rovio’s Angry Birds is mobile app which has what at first might seem like an extremely violent premise; the birds want to get back at some pigs for stealing their eggs and so bombard them in many, many destructive ways. But Rovio always produced the mayhem of the game in a cartoony way — it’s for kids, of course. That’s a premise that continues in the new box office-topping animated feature The Angry Birds Movie, produced by Rovio in partnership with Sony and directed by Clay Kaytis and Fergal Reilly.

But translating the popular app with its 2D action into an animated film was not an easy task. There were several story, character and technical challenges, not to mention the small matter of destroying a barricaded pig city.

"Angry Bird Movie" directors Fergal Reilly (l.) and Clay Kaytis.
“Angry Bird Movie” directors Fergal Reilly (l.) and Clay Kaytis.
The angry in Angry Birds

One of the first challenges the filmmakers faced was how to jump from the mobile game play to a film world and find a way to portray the ‘angriness’ of the birds. For that, the animation team at Sony Pictures Imageworks, led by animation supervisor Pete Nash, initially came up with a highly stylized approach, especially for the main character Red (voiced by Jason Sudeikis). This even included quick Sergio Leone-style cutting of different body parts building in anger such as clenching toes, gritting teeth, and furrowing brows. And Nash also tried out “crash zooming into Red’s pupil to see a vision of himself screaming and hurtling through space.”

"Angry Birds" animation supervisor Pete Nash.
“Angry Birds” animation supervisor Pete Nash.

That would most likely have resulted in a very different movie, and so a more subtle and realistic approach was ultimately taken. This was further developed for other characters, such as the bird Chuck (Josh Gad), who has almost perfect control of his body. Here, Imageworks incorporated observations from actual birds into Chuck’s animation, noticing that they would make quick flutters as if anticipating moves.

The pigs, which in the mobile game survive or perish in elaborately built constructs, similarly had to be re-imagined for the film. Nash noted that the devilish pigs were “treated like a hive mind of compulsive builders who only solved problems in an illogical linear way.” That ensured the pigs had both a particular personality and one that brought the humor. For instance, there is a test where a pig wants to climb a large rock to get to an egg. He brings in a ladder and lays it flat and still cannot reach the egg, so he brings in several more and stacks them flat until he can reach it.

Building birds, producing pigs

Solving character and story was only half the battle, since Imageworks also had to translate 2D characters from the game into suitable 3D birds and pigs. Whereas the game’s inhabitants have no arms or legs, clearly these were elements that the studio needed to revisit for the film, along with some way of depicting feathers and the various ‘powers’ that the birds have for wreaking havoc later on.

While Imageworks looked to preserve the simplicity of the game characters, the result was actually deceptively simple models and rigs. That’s because the head and body of the birds and pigs occupied the same space and made it hard to make the usual deformations work for every case. At first, when a character’s head turned that would also twist the torso and when the mouth opened it affected the body all the way down to the pelvis. However, Imageworks had a solution. They treated the characters like flour sacks, making them squashy and stretchy with clear silhouettes. And they made them adaptable.

The best example of this was Chuck, who was deliberately malleable and crafted to incorporate “as many storytelling poses as we possibly could,” said Nash. When Chuck runs fast his feet would look like ellipses or figure eights — it was a deliberate ode to Chuck Jones’ Roadrunner. Another character, Bomb, was dealing with much inner turmoil, so when he would try and blow up Imageworks animated the bird to have an aggressive argument with himself that would involve quick and punchy facial and body pose changes.

"Angry Birds" vfx supervisor Danny Dimian.
“Angry Birds” vfx supervisor Danny Dimian.

In any other animated film featuring birds, a studio might have to come up with a technical solution to simulate feathers, something Imageworks has certainly done in the past. But in Angry Birds, the feathers remained within the simplified design approach and didn’t take attention away from the overall forms used to construct each character. “The feathers themselves were created out of millions of hairs,” said visual effects supervisor Danny Dimian, who explained that the Imageworks’ character effects team still ran simulations through the feathers and hair to make them behave properly with the animation.

Doling out the destruction

The pigs of Angry Birds live on Piggy Island inside a walled city. When the birds eventually attack their foes’ home via a slingshot, Imageworks was given the chance to re-imagine the mobile game destruction dynamics into fully 3D rendered chaos. A mix of both hand-animated destruction and physical simulation made that possible. But first, Piggy Island had to be built and it was actually modeled specifically to be destroyed. All the buildings were crafted out of full construction sets (like a real building) instead of the simple shells or display surfaces that would normally be used to render.

To begin the destruction process, animation drove much of the initial design of the destruction moments in a Rube Goldberg or mousetrap style, which gave the animators the ability to control the action with the characters. Then, the effects team took over and created physically based dynamics and simulations that made use of the elaborately detailed digital sets.

For the Imageworks crew, that opportunity to take a relatively simple mobile game and transform it into a film full of living, breathing characters with the same sense of fun and some over-the-top action was certainly a highlight of working on the production. Especially, it seems, with the final destruction. “One of the things that is so much fun in the game is destroying the structures the pigs have created,” said Dimian. “The film takes this to another level – we blow up a lot of stuff!”