Computer Graphics World

November 2008 35 CG I n n n n aesthetically into the backdrops, the artists used realistic textures, acquiring basic ma- terials from photographs and then mixing the textures in Photoshop. ey used this process to create the clothes, leather goods, metal objects, skin, and other materials. With Symbor, the artists then built complex shaders driven by mathematical parameters such as facing ratio and dis- tance to the camera. ey used these Blinn shaders for basic surfaces such as leather and metals, some velvet shaders for clothes and horse hair, and subsurface scattering for the skin. "We had a lot of subtle shading details on things like Zoe's clothes or her Uncle Arnold's clothes: Both wear garments em- broidered with gold and have different vel- vet shaders to give them a sense of fineness and richness," Brach says. Nevertheless, the artists used what Brach describes as a "fat S" shader for the hairs instead of a tradi- tional hair shader, for a soft look achieved with a short render time. Lighting and rendering was done with Mac Guff's Symbor as well, combined with MGLR, the studio's rendering en- gine. e light rig was based on ambient occlusion, which allowed the group to control the mood of the sequence; some- times image-based lighting was used, along with some raytraced light sources. Mac Guff's R&D department created a multilayer system based on various outputs that enabled the group to generate basic layers (occlusion pass, diffuse pass, normal camera pass, and so forth), as well as the possible mask and shader output needed by the compositing department—all in a single process. "We even rendered a layer for each light source, with all the possible information (diffuse, spec, shadow) so we could refine the lighting color in real time within 2D," Brach says. Animated Characters After the modelers were finished, the files were handed off to the rigging department. Each biped character rig—set up in Maya and managed with InK, the studio's in- house tool—contained approximately 75 joints, with 100 or so controllers. "Because this is cartoonish animation, everything had to be squashable, stretchable, bendable," says Mathieu Trintzius, character rigger, "but I wouldn't say that the animation falls into the cartoonish style; it is more realistic animation, with the exception of Hector." Even some of the dragons were rigged with the base system, including the World Eater, although the group devised special rigs for creatures that had unique designs. is also held true for the props. All the characters were then hand-ani- mated in Maya, reflecting a style that ani- mation supervisor Kyle Balda describes as "somewhere between full and a hybrid 'limited' animation in 3D"—hardly sur- prising given Qwak's traditional anima- tion background. "ere is a lot of sappy pose-to-pose animation, but for the most part, the style of the animation is driven more from the personality of the charac- ters," explains Balda. "For example, Lian- Chu hardly moves except for when he is in an action sequence, so his acting is subtle compared to Gwizdo, who moves a lot as he talks, but more or less freezes up when it's time for action." According to Laurent de la Chapelle, animation director, the team was tasked with creating a full feature's worth of ani- mation in about nine months, and with 26 animators divided between the Mac Guff and Trixter facilities—about half the time and resources as a Hollywood ani- mated feature. e groups commonly employed video reference, which enabled the directors to communicate the acting/action intentions for a sequence that was being animated long distance by Trixter in Munich. "is was simply a way to communicate the character's motivation for a sequence, as opposed to using a detailed guideline of the exact poses we wanted," notes Balda. e facial setups were based on muscu- lar movements in the face, rather than the creation of shapes that reference particular phonemes or emotional expressions. In this way, the animators were not limited to the same "F-shape" or the same surprised eye- brow pose. "It was up to them to sculpt the poses themselves based on a combination of the anatomy of the character and their own graphic sensibilities," Balda says. Each character model contained several facial controllers on the eyes and mouth, giving the animators a good deal of free- dom in creating facial expressions. is sys- The characters, including the hulking Lian-Chu and little Zoe, are clearly stylized, yet to fit them into the realistic environments, artists added fine details to the characters' clothing and props.

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