Issue link: https://digital.copcomm.com/i/83694
CG Animation ■ ■ ■ ■ ponent. It might be the lighting component, or a matte we defi ned, the hair on his head, his clothes, his face. Th at gives us tons of extra images we can control in the composite. Nuke loads in the main frame, and sort of automati- cally loads up the AOVs as options to be used in the comp. We customized it a bit. Rather than 50 nodes, we had one that's aware of all the fi les that go with it." Th is tweaking took place on a large scale, as for the party, and on smaller scales, too, to achieve the graphic style Tartakovsky wanted. "One thing we often did was for Dracula," Kramer says. "He had a shiny cape, but Genndy [Tartakovsky] wanted the cape to feel like a black mask. Dark, with no wrinkles, no light. So, we would go through our AOVs, fi nd the specular light, and subtract it from the fi nal image." Learning Experience Non-photorealistic rendering also helped bring Tartakovsky's style to the backgrounds as well as the characters. "We were constantly mitigating detail to focus on silhouettes and the portion of the frame Genndy wanted to focus on," Kramer says. "Th e castle [re- sort hotel] was really detailed. So we ended up throwing backgrounds out of focus and dumbing down the textures. If the action was in mid-frame and the foreground was dis- tracting, we'd darken it way down to get rid of the detail." ture artists had already built Dracula's resort hotel and the immense lobby before Tarta- kovsky arrived. "It was basically done," Kramer says. "[Th e As with the characters, modelers and tex- Crowd Control Animators at Sony Pictures Imageworks typically use a proprietary crowd sys- tem to control simple crowds and Massive software for more sophisticated gatherings. But, in Hotel Transylvania, the crowds—mainly monsters in the lobby or at parties—were somewhere in between. "Animating 60 characters would have been too much," says Dan Kramer, visual effects supervisor, "but so would the overhead in setting up a sophisti- cated crowd system." So, for a shot in which a variety of monsters dance in odd ways, the crew generated simple cycles, applied them to characters, and baked out animated characters. Then, to create the scene, they pulled in the charac- ters, placed them in the shot with simple translations and rotations, and let them dance. "We had a system in which an animator could bring up a little user interface, browse through animated cycles, see a character move in real time, and then drop it into the scene," Kramer says. "It was incredibly light. There was no rig, just polygonal data that we put into Maya. We used 'Sparrow' to stream 100 characters at once. Sparrow is an OpenGL plug-in we wrote to store polygo- nal data on graphics cards in an effi cient way and stream it back. It's similar to the now-public Alembic cache. We could have 100 characters in the scene, and the animators could scrub in real time, grab characters, rotate them, place them, and change the offset." crew] had built a lot of areas for the previous version of the script. Th e reception desk was perfect. But, the castle is immense. We had other areas that hadn't been touched much at all. Genndy tweaked the design as much as he could to fi t his own style and taste." And that happened, sometimes, even after the shots were in production. Layout artists might have already designed camera moves and were ready to send the shots into anima- tion and lighting when the shots went back for changes in texturing and modeling. "It was a challenge to push look-develop- ment, model building, and environments fur- ther into production than on previous shows," Kramer says. "We were building the bridges as we were going across the canyon. We kept pace, but we were much closer to lighting than we're normally comfortable with. We were do- ing look-dev on characters and environments a month and a half before we wrapped." result was stunning, and the crew learned from the process. "We often knew exactly where the cameras Th ere was a good side to this, however. Th e were," Kramer says. "So rather than building whole environments and over-building, we could build more effi ciently, which was im- perative when we were so close to lighting. I'm going to think about this system for the next fi lm—decide how much we build ahead of time, how much to hold off on. We might need to crew the fi lm diff erently, but I think some sort of hybrid might work. Sometimes we were too close to the metal. But other times it was more effi cient." When you look at the character animation and clean graphic design of this fi lm, you might think, "Oh, simple." It wasn't. Creating the look and feel of a hand-drawn, 2D animated fi lm with 3D tools, especially with characters and environments designed for another style, was diffi cult. It was a creative process, as well. "I was looking for something diff erent," Crossley says. "Th is fi lm was a creative, fun project. It had a unique energy. And, I could see on the faces of the animators, 'Wow. Th is show is diff erent.' Th is project changed so much, but in such a positive way, and in ways I didn't expect. I'm really proud and glad to have been a part of it." ■ Barbara Robertson is an award-winning writer and contrib- uting editor for Computer Graphics World. She can a be reached at BarbaraRR@comcast.net. August/September 2012 15