Issue link: https://digital.copcomm.com/i/48986
n n n n Character Animation His world has been in live action and film, and live action is a world we understand. The fact that we're using animated characters and we aren't filming backgrounds didn't make any difference. We're composing and lighting as though we were on a live-action film. The biggest issue for me, though, was the interiors. We had to push our indirect illumination." Using RenderMan, the lighters sent rays inside a point cloud, which was a simplified color version of a scene. "Then for final beauty renders, the surface shaders did a lookup into the point cloud to do the indirect illumina- tion," Stables says. "For shadows, we used our PantaRay to generate big point clouds. When the shader executes the final beauty pass, the specular looks up into the point cloud, as well. It's not a mirror type of reflection. We weren't doing caustics; we weren't bouncing specular around. But we were getting a glossy reflection." The test case was a sequence that takes place within a ship's corridors. "We couldn't get away with just diffuse light," Stables says. "We had to account for specular light. We couldn't do the kind of cheating and magic lights we might have done in CG. We didn't want to, and also, Steven Spielberg is extremely particu- lar about lighting." The indirect specular and indirect diffuse lighting were especially important for lighting the characters. "Because specular is angle-depen- dant, it's really the main component that allows you to read the shape of an object," Wojtowicz says. "So a lot of our look development centered around dialing in the specular qualities to their best, especially with Tintin. In the comics, his face approximates a sphere, and to be faithful to a degree to that, he's geometrically simple." The more haggard characters, like Haddock and Sakharine—older, more mischievous, with interesting geometry in their faces—are easier to light. Tintin's simple, youthful face gave the lighters nothing to hang shadows on, no angles. "We had to squeeze details from a wide array of techniques, and one of those was having an intricate specular response," Woj- towicz says. "If we were to put Tintin in his apartment with its walls of brightly colored wallpaper, and put a couple of hot light sourc- es at either end, the entire room would light up and wash him out with all the diffuse light contribution from all the angles in the room. So, if we don't have a specular reflection, we lose his shape. We even used indirect specu- lar in exterior scenes when we needed to in- crease the visual complexity of an object mov- ing through the scene, or the camera moving through the scene. We were more selective because it's a bit more expensive in terms of 18 December 2011/January 2012 render time, but we did use it." Because Tintin chases through several coun- tries during the film, the lighters faced situa- tions ranging from the desert in the middle of the day to overcast oceans, and all the lighting needed to interact in a consistent manner with the new hair shading models and the new sub- surface scattering models for the skin. All this attention to detail—the new muscle system for the characters' faces and Snowy's shoulders, capturing skin textures, new hair and fur systems, new shaders for hair and skin, the 1600 variations of Tintin that it took to produce a character that looked right, the re- search into reference materials and research into scientific methods, and more—combined to make a film that critics such as Variety's Les- lie Felperin praise: "The motion-capture per- formances have been achieved with such exac- titude they look effortless, to the point where the characters, with their exaggerated features, what's around it digitally," Letteri says. "The whole shot becomes digital, and most people don't know the difference—and that's the in- teresting part. It doesn't matter. So, it's hard to define the lines these days. In a way, that's what Jim [Cameron] was trying to do with Avatar. There should be no barrier moving between these different worlds." "But," Letteri continues, "live-action visual effects ground you. You have a photographic plate. You judge everything by the pixels next to it. You know when it doesn't work. And I think that was the hardest thing about [mak- ing an animated film]. If you're going to try to make it look real, you need a touchstone for reality. In a world that's completely digital, it becomes easy to convince yourself that some- thing looks good because it looks better than the last time you saw it. But if you put it next to something real, it doesn't [look as good]. So we couldn't let ourselves be convinced. Because The challenge for the water-simulation team was in creating photoreal water in a comic-book style. An up- dated Fast Fourier Transform library for the waves, Smoothed-Particle Hydrodynamics for cresting foam, Exotic Matter's Naiad for hero interactions, and Weta's own Synapse fluid-simulation software helped. almost resemble flesh-and-blood thesps wear- ing prosthetic makeup." Asked how he was able to keep the char- acters in Tintin out of the notorious uncanny valley, Letteri's answer is, "We didn't try. We weren't thinking about it. To tell you the truth, the question only came up when other people started asking about the movie. For us, these are just characters we like to watch. They either work or they don't, and if they don't work, you can call it whatever you want. When you're working on a film, you're focusing on the spe- cifics. Is that eyelid doing the right thing? Is that lip doing the right thing?" But certainly the studio's experience with live-action films, with the rigors of matching the real world and often substituting virtual for real, had an effect. "In live-action films, when you have a visual element that isn't real, it's becoming easier to create the reality and we come from visual effects, we strive for accu- racy, to make everything believable. We photo- graphed lots of reference. We constantly judged against something real. When we needed to know what Tintin's hair looked like wet, we persuaded someone with red hair to cut it like Tintin's and soak his head in a barrel of water." There you have it. If you want to stay out of the uncanny valley, soak a redhead in a barrel of water. And then hire the best artists and researchers you can find, ones who work me- ticulously for years to make the world on the movie screen seem real. n Barbara Robertson is an award- winning writer and a contributing editor for She can be reached at BarbaraRR@comcast.net. Use your smart- phone to access related video. Computer Graphics W orld.