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True Colors

Jun 9, 2007 1:00 PM, By Michael Goldman

A look at color grading and cinematography on Ratatouille, Shrek the Third, and Surf's Up.

Navigation
Introduction
Ratatouille
Shrek the Third
Surf's Up
Sidebar: Grading Bees, Handling 3D
Sidebar: Bird's View of Paris

Mockumentary blues

For Sony's Surf's Up, an animated “documentary” about surfing penguins, Sony Pictures Imageworks' art director Ron Lukas and visual effects supervisor Rob Bredow were the two keepers of the movie's color palette. Lukas headed up the effort to build an extremely detailed color script in Photoshop, (see below) and supervised the key scene painters, while Bredow managed the effort of executing that template in 3D.

The two then worked together with Imageworks' senior digital colorist Paul McGhee, operating in a Lustre (v. 2.7.1) suite during the DI to finalize the entire palette.

“The color ideas in the movie mainly started from the locations, which were very distinctive color-wise, since there is a fundamental contrast between Shiverpool, our version of Antarctica, which was cold and blue-gray and freezing, and Pengu Island, which is a tropical Pacific Island paradise,” Lukas says. “The lead character, Cody, arrives at Pengu Island from Shiverpool and is blown away by the difference between the warmth of that place and where he is from. So that fundamental contrast drove most of our color ideas. From there, we created a color script based on the outline of the story, designed to ensure color continuity throughout the movie.

“After that, my job was to supervise the painters who color-keyed the sequences, and I even painted a lot of them myself. We completed the movie in color keys, and then I would help the CG department, particularly in lighting, to follow through with our color ideas throughout the 3D process. But early on, we literally had 2D paintings to describe practically every setup. It was all planned and beautifully executed so well that there were no wholesale changes to do in the DI. That was more about making everything match reel to reel and scene to scene.”

Given the nature of the movie's style — created to replicate a documentary with sequences appearing to be shot on 16mm or 35mm film and sometimes on old video cameras — the subtle aspects of color work were central to Surf's Up. So much so that the layout and animation departments had to consider the creative impact their work would have on the lighting and, therefore, the color schemes.

James Williams, head of layout on the project, for instance, normally does not have to delve too deeply into the color plan. His job is to supervise compositional and motion elements in the layout stage, while leaving color issues up to Lukas and his colleagues in the art department. However, Williams points out that the creative nature of the project required him to think constantly about light and shadow implications of everything done in the layout phase.

“Shadows and other aspects of the lighting and tone become compositional elements within scenes, and, therefore, [in layout] we have to concern ourselves with them — especially in a movie like this, where we were doing a documentary,” Williams says. “I recall, in one instance, the two main characters, Cody and the Geek, are having a conversation on the beach, and in order to underscore their emotions, we deliberately played one character in shadow and one character in light to accentuate their separation. Then, there is a reveal, a point of realization in the sequence, where Cody realizes something significant about the Geek, and we use his movement from shadow into light to underscore that. That directly involved light, but was planned in the layout stage. The scene with the roller-coaster ride through the lava tubes had similar issues, as they play light against dark. We ended up texturing the environments to convey that idea across to the other departments. Many of the caverns in the sequence were color coded as we passed it along to help everyone feel the transition from one particular area to the next. Those colors got passed over to lighting, and then they make it a lot more beautiful.”

Bredow emphasizes that Surf's Up is a good example of an animated movie where color was among the most stylized of all the elements — from increasing the emotional impact of bringing viewers out into the water with the surfing characters to increasing the realism by deliberately introducing artifacts and other ways of making the imagery appear less than pristine, in keeping with the documentary approach.

“It's a very detailed movie,” Bredow says. “There was a requirement that the movie be detailed enough that the audience felt they had gone surfing when they left the theater, and that dictated the level of detail we achieved with the water, and all the photographic elements. We have lens aberrations, film grain — things that are part of the language of normal film in a live-action situation. But at the same time, to be stylized, many of the designs and shapes and colors were pushed outside the realm of what you could normally photograph easily. We have realistic water, for instance, but with incredible aqua colors that you would be hard-pressed to find in real life. In fact, after we finished the movie, for fun, we did a realistic water test to make the water look perfectly photoreal, and we found that the real water had less saturation and punch than what we needed for this animated movie.”

Bredow says that for a CG film, the DI is the most precise way to achieve high-quality detail work.

“At the end of the movie, in the sequence where the Boneyard race happens, it's meant to be an overcast environment — a gray day, with the sky just slightly purple and a haze over the ocean,” Bredow says. “Of course, all those colors are slightly different. If you add a little magenta or green to it, it makes a big difference shot to shot. We matched it, of course, as close as we could in the lighting phase, but in the DI, each shot got a half point of magenta, a half point of yellow, and so forth, making it a smooth and continuous environment. That let us be more precise with colors, while at the same time, seeing it in an interactive way one sequence at a time as we went along, to make sure it was all working, and to fix it if it wasn't. Lighting one shot at a time takes hours in live action, and days in computer animation. The DI lets you do it immediately by eye. That's a huge improvement.

“The other thing is, we now have to target multiple release mediums — particularly the digital cinema and film releases — and that means the colors will all be slightly different. The DI process is where we absorb the difference between those two target mediums and work it out to be very close to a 1:1 correlation. That is how we were able to refine blue/aqua-green waves on Pengu Island to look right for both versions — they are really the hero shots of the movie.”

As complicated as it remains to establish a consistent color look for digital cinema that can translate seamlessly to the film world, Bredow and McGhee say the art of color science and Imageworks' sophisticated LUTs have greatly streamlined that process.

“For this movie, our main grade was done for the XYZ pass for the digital cinema version,” McGhee says. “Our color scientists have made great look-up tables which allow us to transfer that grade to film and to HD. Then, there are shots that get small tweaks to look better for the film version. But for the most part, by changing the color LUT, we can get it very close for the film version during the main pass. We still do lots of tests with the lab [Deluxe, Hollywood] for the film version, and we did an answer print correction in the lab on Surf's Up [for the film version], which is still common. But for that process, for the most part, we only need to do an occasional one-point correction for one sequence here or there, and that is very minimal. That has been the case on our last two [CG] shows — Open Season and Surf's Up. So that shows how the color science has improved.”

© 2008 Penton Media, Inc.