Issue link: https://digital.copcomm.com/i/739236
22 cgw s e p t e m b e r . o c t o b e r 2 0 1 6 woodblock print, yet it had to behave like the water in nature. Helming the challenge was Effects Lead David Horsley, formerly of Rhythm & Hues. Working with Emerson, Horsley developed the fluid simulation in Side Effects' Houdini, blending it with mesh geometry and Ren- derMan displacement shaders that captured both the whirling and scoop patterning sought for the waves. Effects artists also used Houdini and volumetric shaders for the ominous wall clouds and thunderheads that roll toward the boat, laying them into plates using The Foundry's Katana and Nuke. Houdini also powered the effects for the sea spray and the water flooding the deck. For the driving rain, compositor Timur Khodzhaev developed a 2.5D system that incorporated Houdini particles into Nuke. Laika divided the fight sequence aboard the boat into two sections, above and below, separating Monkey's battle with the Sisters on the deck, and Beetle's attempt to rescue Kubo underwater in the Garden of Eyes. From their pipes, the Sisters blow long, black tentacles of smoke that chase aer and seize Kubo, spinning him around like a ragdoll. Laika wanted the look of these Smoke Demons to inform and echo the driving snow of the blizzard in the film, particularly gusts of the denser ground snow. VFX artists generated both the snow and smoke in Houdini using particle simulations driven by force vectors, while animators added significant keyframe animation for the Smoke Demons, as well. E X T E N D I N G S E T S A N D C R O W D S Almost every stop-motion set in the film is greenscreened and paired with a CG set extension, lending an epic scale to the village and Kubo's promontory home, for example. But one of the most important extensions furnishes the Hall of Bones. In this sequence, Kubo plunges from the snowy Far Lands into a bejeweled subterranean hall guarded by a 16-foot skeleton monster. The stage set was 360 square feet, with a very short wall encrusted with 380 12x12-inch jade-colored resin tiles encompassing two-thirds of the set. The CG set elevated the wall to an imposing 22 feet, employing a RenderMan shader for the jade tiles with subsur- face scattering. "We ended up building just one wall and rotating it around, using shader variations to add variety for each tile," says Wachtman. "Using the one wall, we set it all up in Katana, and used the hierarchy copy, which lets you make another scene graph of the same wall and use attributes to drive shader parameters." A pivotal moment of the film sees re-animated ancestors rising from the lanterns in bodies of silvery moonlight. To create the apparitions, the VFX depart- ment modeled the ancestors in Maya based on a plastic puppet that had been lit from within, like a lantern. "We built digital characters to do the same thing," says Wachtman. "The first thing we did was write all our shaders using [Pixar's] Slim and the RSL-based system we used for the film. We wrote our own little subsurface scattering that would deal with the light from the interior and refraction." Using Katana, the shader was hooked up to the asset. In Katana, artists rigged three little geometry lights in- side the head, chest, and base of each character's kimono, all of which shed the light that il- luminates the scene. On closer inspection of the ancestors' transformation from lantern to spirit, audiences will see, graft- ed subtly into the transition, Saito's woodcut textures. This scene is one of the few to feature digital characters. In fact, even the hyperkinetic origami animations were creat- ed by stop-motion animators. Among the only CG origami in the film were a flock of birds that join a songbird in flight above Kubo as he treks through the blizzard, all of which were modeled and keyframed in Maya based on stage-animated origami overseen by Character Supervisor Brad Schiff. H E A R T O F R E S I N Indeed, far from being lud- dites and purists fossilized in a stop-motion world, Laika wants to embrace every tool at its dis- posal, from photorealistic CG to squash-and-stretch. Kubo and the Two Strings is easily its most ambitious film, not only in the breadth of its technical and ar- tistic reach, but also in the depth of its themes and emotions. But the bulk of its dramat- ic accomplishments were powered by innovations in rapid prototyping, innovations that McLean hopes will continue, especially in the area of perfect- ing the fidelity between Maya model and printed resin. "When you look at Monkey and Beetle and how they perform, especial- ly Monkey in the cave, there's so much tenderness and subtlety in the performances that gives me a lot of confidence that the polyjet technology is the way we're going to get the most out of these characters." ■ Martin McEachern (martinmceachern@hotmail.com) is an award- winning writer and contributing editor for CGW. An interview with Kubo Director Travis Knight THE MOON BEAST IS A COMPLEX, MULTI-LAYERED CHARACTER.