In The Boxtrolls, 3D Printing Makes Stop Motion Animation Look Magical

The Boxtrolls takes you into a beautiful bright Dickensian world where cheese means status and box-clad trolls are at the bottom of society. It’s the biggest stop motion production ever and it would have been impossible a few years ago. But the creators of the film took a 75-year-old technique and introduced a whole new set of modern tools. The result is pretty magical.

First of all, what exactly is a Boxtroll? A Boxtroll is a character who is part troll, part box, a denizen of the world below the fictional town of Cheesebridge. Boxtrolls are on the endangered species list, painted as evil creatures who snatch the town’s children. They are hunted by the villain Snatcher, a wolf in vigilante’s clothing who’s brokered a deal with the town’s elite that will allow him to join their fancy cheese-eating ranks, only once he has eradicated the town of the Boxtroll menaces. Among the Boxtrolls lives Eggs, an actual boy raised as a troll, to save him from certain death on the mean Snatcher-patrolled streets of Cheesebridge.

Cheesebridge is a colourful little town that seems to exist within a much bigger world. In reality, it was built on a very small stage. That’s part of the magic of stop motion, but more on that in a bit. The personalities of Cheesebridge’s citizens, played by puppets, controlled by human actors, are vibrant. Their faces are expressive, and in each shot, each slight change in emotion, they’re wearing a different face — one that someone on the Boxtrolls’ 400-person crew at Laika studio to make.

And it takes a very long time. One week of hand-acted movements will make just one or two minutes of a stop motion film (that is unchanged and will never be unchanged, because the physical part is a part of stop motion in its essence).

Quick history lesson: Stop motion is about as old as film itself. The first example of the frame-by-frame animation process is 1898’s The Humpty Dumpty Circus, a short film that centered on toy circus animals and acrobats. Filmmaker Willis Harold O’Brien brought to life King Kong in 1933, using methods that are still used today, and in some form, were used in The Boxtrolls.

Stop motion is a taxing, tedious process. A film will start with a story. In this case it was a very detailed story, based on the children’s book, Here Be Monsters by Alan Snow. Then the studio will move to 2D designs, then renders, then actually physically building puppets and sets.

The process has essentially remained the same since for decades and decades. But recently, stop motion animators have been able to do more, and The Boxtrolls is one of the biggest, if not the biggest stop motion productions ever created. By and large, that’s thanks to 3D printing, which allows the creators to make facial kits with every possible expression all on the computer, then print them out.

That’s tedious as it is, but it’s not even getting to the tip of the iceberg. The Boxtrolls had 79 sets, more than 20,000 props, one “hero” or main puppet for each character, dozens of replicas for various poses and stunts, and thousands of expressions for their little faces. And humans have to move each teeny weeny part.

“Mechanical face animation is a bit like Swiss watch-making for the puppet head; the animator hand-manipulates the character’s facial expressions through the silicone skin,” Georgina Hayns, Laika’s creative supervisor of character fabrication says. “Eyebrows, jaw, lips — they are all adjusted by hand. Our human background puppets in this movie all have mechanical heads. Some of the puppets with mechanical heads have gears that can be accessed through their ears!”

Tiring as it may sound, Laika is only pushing the boundaries further. Boxtrolls is the studio’s third stop motion movie after ParaNorman and Coraline.

“One of the unique things about Laika is they have been together for three films. That never happens in stop motion. Usually stop motion crews up — like with a Tim Burton film,” One of the directors, Anthony Stacchi told me in a phone interview. “A director pulls them together and then they break up, or they go off and work on TV shows.”

Sticking together has worked in Laika’s favour. Each film has built upon itself to create a new movie more magical than the last. Laika has built proprietary software, and teams have learned how to work faster and work better. Perhaps even more importantly, the studio has benefited hugely from the development of 3D printing.

In past stop motion productions, someone in the faces department (Laika’s largest department) would have to create by hand a new face for every single expression a puppet made. Now they can render them on a computer and print each one out in brighter, more nuanced colour, and print them out more quickly than hands could make them.

How does that translate into what you see on a movie screen? The film Coraline, for instance, had 207,000 possible expressions total. Eggs, the hero in Boxtrolls, had about 1.4 million.

“I think if the people in Coraline had been able to look in the future and seen the faces we were doing for the Boxtrolls, they would have quit on the spot because it just wasn’t possible. Because we print everything now in full colour right out of the printer,” Graham Annabele, The Boxtrolls other director told me. “Part of the design in the Boxtrolls, the characters, we have little touches of colour and lines, that stylistically put our characters in the wacky world that we’ve created. There are a ton little lines and things all over the place a few years ago that would have never seemed possible.”

But 3D printing has made a new type of rapid prototyping possible:

“It’s] the subtleties that the printers are capable of, which goes back to the printers themselves but also the materials that they’re putting through them now,” Staachi said. “The faces have a look kind of like a Lucian Freud portrait or even an Egon Schiele painting where the colour variation is very subtle.”

The printers lend themselves to speed and add this depth of emotion to characters and allow the animators to create a bigger, brighter world. That’s something that’s better appreciated when you think of The Boxtrolls in the context of The Nightmare Before Christmas, also a stop motion film. What they’re doing — making these replacement faces — is no different now in 2014, but it’s a more advanced process.

Staatchi told me: “Jack Skellington from Nightmare Before Christmas has replacement heads where they were hand made. You can see them. They can only get a certain amount of consistency when they’re hand made. So you can see them jerk around and stuff. That’s why it really helped in the design of those characters in that world that there was a certain simplicity to the head shapes. Our characters have a more caricatured or more realistic look to them and much more complex shapes to them. Only by doing it by computer, printing it out could we have kept the performance consistent and like you said, having the ability to print more faces just allowed us to add more subtlety to the characters performance.”

How do you see these things translated to film? First, as a viewer, you always always believe that Cheesebridge exists within a larger world, even though it’s filmed in a tabletop set. (Another credit to Laika is that it has a CG department that adds elements to the backdrop). Second, there are huge action sequences in The Boxtrolls that couldn’t have been possible in previous stop motion production.

In those scenes there are tens to hundreds of characters with intricate costumes that move fluidly and realistically. The hoop skirts sported by Cheesebridge ladies presented a particular challenge, but it seems effortless on screen. Then there’s the depth of emotion that the characters truly express. It’s real — I felt it!

In the movie, Eggs befriends a little girl, Winnie, a daughter of a member of the Cheesebridge upper crust (Lord Portley-Rind) who is obsessed with Boxtrolls. Eggs has been raised by Boxtrolls and thinks he’s a Boxtroll, so the two come from two different worlds. But in one moment they connect:

“[There’s the scene] when Eggs and Winnie are sitting on the edge of the cavern wall and they’re talking about what fathers are and those faces have very subtle colour changes and very subtle transitions because those performances are subdued there,” Staatchi said. “You just see these little minute changes on his face where he’s getting happier and she’s getting sadder when she’s realising that her father doesn’t live up to this idea. It’s amazing that the subtlety of the performances and what Rachelle the animator did for them — the tiny little movements that they’re making.”

Every day on set, there was an animator making sure that those emotions looked real and not like a dead little puppet just lying there. And both directors assured me that “what you see is what you get” in The Boxtrolls. But to see these concepts come to life, you have to see the movie. And you should! Especially (but not only) if you’re taking your kids. It’s one of those movies laden with jokes that work for adults and kids.

It’s worth seeing for the impressive technique alone. While kids can appreciate the magic, you can only fully grasp what you’re looking at when you understand that the 100 minutes of film was created through thousands and thousands of hours of animations. Make sure you stay through the credits!