Three months before Laika’s 3-D stop-motion feature ParaNorman was set to start production, the company’s breakthrough workflow technology—making puppet faces via 3-D color printing—was spitting out disasters.
"They looked awful," says Brian McLean, Laika’s director of rapid prototyping (RP, or 3-D printing). "The skin tones were terrible and inconsistent. What you saw on the computer screen was completely different than what printed out. There were some 'Oh shit!' moments when we realized we’d jumped head first into shooting this movie using this process, and we now had to figure out a way to make it work."
By sheer force of will, scientific process, and ulcer medication, McLean’s team solved the system quirks. The result—a comedic thriller arriving Aug. 17 about a misfit boy who can talk to the dead—showcases unprecedented character design and emotional nuance for that medium.
"Stop-motion has always had the advantage of beautiful sets, atmospheres and textures," says McLean. "But the facial performances have always been a little limited. Now, with the advent of 3-D printing, there are no limitations."
This artistic leap comes courtesy of an incremental technological progression. The time-honored stop-motion technique is known as replacement animation—literally replacing faces with different expressions, taking photos of each one, and stringing them together for the illusion of movement. From the 1920s on through to The Nightmare Before Christmas in 1993, artists would hand sculpt faces with varying expressions—in the case of Nightmare, roughly 800 heads for its lead character.
"It was very laborious to hand sculpt each of these expressions," says McLean. "It took a long time and the [final onscreen] movement was a little choppy, but you got your point across."
For its first stop-motion feature, Coraline, which was released in 2009, Laika tapped then-emerging 3-D black and white printing technology. Artists would animate faces in a computer, using Maya software, then print them out as 3-D sculpted objects. "We could remove the bottom and top sections of the face, so we could independently replace the mouth or eyebrow sections, then digitally erase the separation line in post production," says McLean. The result: some 200,000 possible facial expressions for Coraline, smoother lip-synching, and greater emotional range.
There was just one catch: the faces still had to be hand painted, including Coraline’s freckles. "Believe me, we negotiated back and forth with the director, because we knew that every freckle added meant some poor painter had to paint thousands of freckles in the exact same spots—otherwise, they would seem like they were dancing around her face and ruin the illusion," he laughs. "So, we were able to push the performances on Coraline, but the character designs were watered down."
Enter ParaNorman. By 2010, 3-D color printing—in its infancy during the Coraline production—had progressed to the point where artists could conceivably paint faces in the computer and print them out in color.
Although preliminary tests were successful, making an entire feature reliant on color printing "had never been done before," says McLean. "But in order for us to move forward, we had to take this chance."
That’s when disaster hit. The four printers kept spewing out colors that were inconsistent with those on the computers and each other. "People take it for granted," says McLean. "But Epson and HP have probably spent about 30 years on color profiles and scientists figuring out how the colors you see on your computer and coming out of your printer are going to match. This technology [3-D color printing] was in its infancy and we were trying to take this machine and push it to new levels and complex paint jobs. All we could do was put our nose to the grindstone and do thousands of tests to figure out the best file formats and color profiles to send to the printer."
McLean’s team had to then figure out how to handle the faces—which were printed out of powder and had the consistency of chalk. The team had to dip them in Super Glue, sand them and bake them in an oven at specific temperatures and times for different effects. "We had to find, then follow, these steps exactly, or the parts wouldn’t match up," says McLean. "At the time, we thought, 'Is this even gonna work?' There were these mystery steps we just had to discover. We only had three months to do it. It was insane.
"There was a turning point," he adds. "For a while, we were a thorn in the side of this color printing company, 3D Systems, because we were constantly calling them up and saying, 'This color is off, or not working correctly, or we’re printing a red sphere and it’s coming out half red and half orange.’ We were using four different color-printing machines—the exact same model—and each would print a different color red. There was no rhyme or reason. They couldn’t figure it out."
With a month to go, some 3D Systems technicians flew to Laika’s Oregon headquarters and flipped when they saw the meticulous documentation—from the temperature and humidity of the room to the steps followed for each test. "From that moment, we had a direct line of communication with their lead color scientists and head engineer," says McLean. "That’s when we really started to be able to perfect it, and a lot of innovation really happened. And when it started to work, it was even better than we thought."
While some of the character designs or effects were immediately apparent—like Norman’s 8800 faces and 1.5 million expressions, or the explosion of freckles on Norman’s best friend—others were the results of happy accidents.
"We sent a bunch of faces to the printer, and instead of laying them all out in a grid, like it was supposed to, the computer stacked them all on top of each other," says McLean. "We didn’t realize it and hit print, and we got a face that was 50 faces stacked on top of each other, with all these noses. We realized, that’s basically motion blur—that illusion of motion you see in comic books where a character is throwing a stick and you’ll see multiple sticks drawn. We could suddenly do that with a 3-D printer."
The color printer also allowed them to give the replaceable plastic faces the patina of silicon, which made for easier blending when placed on a silicon head—particularly handy for one no-necked bully character, Alvin.
Silicon is similar to skin in that it absorbs, then gently reflects light, compared to the bounce-off effect of plastic or metal. "The printer injects color a 16th of an inch into the face, not on the surface, which allows for a technique called subsurface scattering," says McLean. "So you could have this character with a hard printed face next to silicon, and once you remove that seam line in post, you have this beautiful transition of these two materials matching perfectly.
"That translucency and vibrancy of the face was something we took advantage of," adds McLean. "Norman’s ears have a kind of translucency to them—like real human ears that let a bit of light shine through. That’s a direct result of using this material, technique, and technology."
Meanwhile, the RP department wasn’t the only one making technological advancements. The armature department, lead by Jeremy Spake, perfected the puppet’s metal skeletal, and ball and socket structures that facilitated smoother and more exact, incremental movements. Norman’s face, for example, contains magnets to hold the face in place, and over 78 engineered elements, screws, and 3-D printed plastic pieces, mostly to give heightened control over the eyeballs and lids for enhanced expression.
"Rapid prototyping is probably the most visible improvement from Coraline to ParaNorman, but there are all these other underpinning technologies—laser cutters to mold making and painting techniques, to costume movement control to visual effects for set extensions, ghosts, and storm effects.
"We’re constantly using technology to solve problems," adds McLean. "You don’t save any time or money. Because the advancements make it easier to produce these things, you can suddenly create more, and push the performance to do things that were never possible."
Check out the above slideshow as well as Chuck Salter’s ParaNorman story for more behind the scenes shots.