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n n n n Stop-Motion Animation second, and change face parts to create facial expressions 12 times per second. "Animating on twos gives us more pop," Knight says. "If we want more subtlety, we might animate the faces on ones." When the animator and facial animation specialist have assembled all the digital face parts into the series of expressions they want—per- haps of Norman screaming as he runs from zombies, or frowning, laughing, or smiling— they show the playblast to the lead animator or director. "If he approves the playblast, we cre- ate a shopping list of face parts," McLean says. The shopping list goes to a face librarian, who picks all the physical face parts for the shot. and white whites, which had been the Achilles' heel," McLean says. The studio decided to test the printers with a little model of a zombie head. "When we got it back, it looked fantastic," McLean says. "The yellows were vibrant. The greens, consis- tent. We purchased the machine." Thus, rather than hand-tinting each face part, the artists could use Photoshop to paint one digital part and print multiple copies in color. They would soon learn there were other advantages as well. It wasn't easygoing in the beginning, though. When they first tried printing faces, the skin tones looked terrible. What the painters saw on screen was not what the machine printed. Except for the zombies. "We asked if our machine was bro- ken," McLean says. "They told us that the machine prints green and yellow really well, but other colors can be a problem." Character painter Tory Bryant took the problem in hand. "She went through McLean explains that the characters in stop-motion films that use faces animated with replacement parts have lollipop heads— big heads on little bodies—for a reason. "It's a wonderful design, but it's also a side effect," McLean says. "The bodies are made of sili- con, which is translucent and has color all the way through, so you have subsurface scatter- ing. But, you can't put a hand-colored, hard, printed face next to the translucent body, so you need a long neck." But now, with the color printer, they could put the translucent, color-printed face next to a soft silicon body. "We created Alvin the bully with a thick neck," McLean says. "We could never have done that before. That's one reason why the designs in ParaNorman are so unique." A big inventory solved any problems with continuity. Although each printer outputs slightly different shades of red, the colors fade through the life cycle of the printer heads, and humidity and temperature affect the color. "When you have 10 or 15 copies of a smile, These go into a box that the animator takes to the set, along with an X-sheet that lists expres- sions and face parts frame by frame. "Because this might be the first time these faces appear in sequence, we run tests to be sure the color and registration are accurate," McLean says. Printing Makeup Color was the major difference between the process used at Laika for ParaNorman and Coraline. "For Coraline, we used the plastic printer," McLean says, "the same one we use now to print eye parts. So we hand-painted her face. That's why she has five freckles on each cheek. We needed to keep the paint re- ally simple." At left, the physical tornado and layers of tulle (middle) created and manipulated in the art department provided reference for the CG stormy skies in the image above. In that shot, when the witch moves her face, volumetric CG clouds react. the Pantone book, the thousands of colors, and printed each as a physical chip," McLean says. "That became her palette." color, the crew's excitement about this new pro- cess grew. "We realized the printer puts color one-sixteenth of an inch deep into the model," McLean says. "That was unlike anything we' As they tested the machines to calibrate the When 3D Systems' new color printers became available, they considered new possi- bilities. "Color printing had been around for a while, but the new machine had rich blacks 36 August/September 2012 seen before. In addition to getting wonderful colors, this technique gave us subsurface scat- tering for free. The model didn't look like a thin shell; it looked and felt like skin. We realized we could put color where we wanted, so we put a little red inside Norman's ears, and they looked like real ears. And that broke us free to do a lot of other things." Most important, they could change the characters' designs. d you can find faces that match," McLean says. "Tim Yates, our face librarian, can look at hundreds of face parts and pick the ones that work well together for color." Once an animator finishes a shot and the shot has made its way through editorial, the faces move back into a CG pipeline where artists on the visual effects crew paint out the seams between all the face parts. They also work on the entire shot, removing rigs and, sometimes, reconstructing sets. "We do all the traditional, invisible effects," says visual effects supervisor Brian Van't Hul. "Sometimes an animator will have to cut away a portion of a set to reach the puppet. We shoot a clean plate and tell them to go for it. These are paint and roto tasks no one will no-