Dec 24, 2016

How Leica Animates Giant Eyes using Bowling Balls - Kubo and 2 Strings-

Stop motion is by its very nature one of the most hands-on kinds of animation. But how do you animate a giant underwater eyeball frame-by-frame- It's something Laika had to conquer for Kubo and the Two Strings. The solution rested with a bowling ball.

That's right, a bowling ball. And it was just one of the techniques used to produce the crucial 'Garden of Eyes' sequence in the film, which also involved significant model fabrication, traditional stop motion, digital plant life, cg water, greenscreen compositing, and other visual effects.

Cartoon Brew finds out more about the bowling ball solution, and other aspects of the sequence, from key members of the Laika crew.

In the sequence, Kubo dives below the water surface in search of his father's magic armor. But he encounters a shoal of giant eyeballs. Laika's rigging department worked with the lighting and camera departments to devise how the giant eyes would look. Just one was built and then replicated for the shoal.

“Essentially giant illuminated sclera on stalks, the creatures incorporated an array of LEDs seated behind the pupil, shining through counter-spinning rippled domes,” said animation rigging supervisor Oliver Jones. “A 32-inch perspex ball filled with a steel fabric mesh picked up the tiny specular flashes and swathes of cascading light. The end result is an electric and mesmerizing moiré effect that hypnotizes both Kubo and hopefully the audience.”

Since Kubo's stop motion puppet was about six inches tall, the entire eye creature puppet had to be built at a size that would achieve the correct scale. The result was that it stood at a hulking 11 feet. In order to control the eye, Laika came up with a semi-automatic solution – the bowling ball.

“Instead of moving the puppet by hand,” explained Jones, “we devised intuitive remote interfaces for a stop motion animator. A bowling ball was transformed into a giant trackball with two hacked computer mice translating the rotating coordinates into a three-axis rig that in turn rolled the puppet's floating eye. A miniature proxy puppet with 'off-board' encoders controlled the body movements.”

This robotic system meant animators did not need to move each of the eye's 16 tentacles frame by frame. Here, instead of a traditional ball-and-socket armature, cables were tugged by stepper motors installed internally on a telescopic ribcage. “We choreographed a swim cycle nicknamed the 'Garden of Eyes dance' which supplemented the animators' key-frame performance,” said Jones. “Pre-programming and recording animation dramatically cut down stage time.”

Since the sequence takes place underwater, Laika had the additional problem of making Kubo's kimono and his hair move realistically. Animation supervisor Brad Schiff turned to real world reference for guidance. “I went to our local gym at lunch one day, and, wearing a kimono, jumped into the pool shot and shot video reference of myself swimming around. It was incredibly useful to see how the fabric of the kimono and my hair moved underwater. This reference informed how the kimono needed to be built to get the heavy flowing feel of being underwater.”

The stop motion cloth kimono was originally crafted with extra support material and Tyvek backing (a kind of polyethylene fiber used as a weather barrier) so that it didn't move around during animation. So for the underwater version, this material was taken out and extra wire and foil placed in the sleeves, cuffs, collar, and ends of the kimono. “That gave the animator, Danail Kraev, the ability to get the finite organic shapes in the costume needed to emulate the look of it being underwater,” said Schiff.

Of course, that was only part of the solution to make the shots look like they were happening underwater. Kelp plants in the scenes were also fabricated and rigged practically with fishing line to programmed stepper motors. They were then filmed under multiple lighting passes from several angles, and replicated by Laika's visual effects team to form an extensive library of submerged forest.

The vfx team was also integral in bringing all of the elements together – the eyes, kelp, and characters which were sometimes animated separately against greenscreen. “The art department was very specific with the layout of the environment as well as the scale of the kelp and monsters relative to the puppets,” said visual effects supervisor Steve Emerson. “Timur Khodzhaev was the sequence lead. He set up a system in Nuke so that we could get accurate depth for plankton. Then, along with senior compositor Ralph Procida, worked very closely with the art department and camera team to dial in the color, atmosphere, and volumetrics.”

Although an attempt had been made to stop motion animate Kubo's hair for an underwater feel, it was determined to do a cg replacement after some early tests. “That allowed the stage animators to focus on cloth and puppet motion,” said Emerson. “It's the only hair replacement that we did in the film. All other puppet hair performances were done in-camera by the stage animators.”

At one point, Kubo has a direct encounter with one of the giant eyes. It puts him into a hypnotic state that leads him downwards towards the monster's enormous mouth.

“The original storyboards showed Kubo's eye turning white, but director Travis Knight was interested in exploring other options,” related Emerson. “Our lead compositor, Michael Cordova, came up with many ideas, but the one that Travis really responded to was a dilating pupil that transitioned into the look of the Garden of Eyes monster eyeball. He did it all in 2D. He sourced a plate of the monster animation, extracted the eyeball portion, then warped, tracked, and integrated it onto the Kubo puppet.”

This shot, perhaps more than most, emphasizes the way Laika has never shied away from taking advantage of as many resources as possible to bring its films to life. This means that both practical and digital methods were considered. Indeed, so critical are the digital methods that Kubo is among the 10 shortlisted films under consideration for the best visual effects award at the Oscars.

“I'm really proud of the underwater work that we did for Kubo and the Two Strings,” said Emerson. “Mostly, in that so much of it was realized through inter-departmental collaboration across the studio. There's something about having stop motion animators, set builders, and puppet makers collaborating with digital artists that takes us into some really unique visual territory.”