Issue link: https://digital.copcomm.com/i/119349
n n n n VFX•Stereo 3D Oz was filmed entirely on stage. There were no exterior locations. Most of the landscapes were hybrids with a set piece in the foreground, CG set extensions in the mid-ground and background, and matte paintings in the far background. tastical landscape, a land of jagged peaks and water alls, and into a lush area. All through the f movie, we explore different corners of Oz." Production Designer Robert Stromberg, who won Oscars for the art direction on Avatar and Alice in Wonderland, created the concept art for the film. To further guide the postproduction crew, he painted over dailies shot on the elaborate sets. "Robert married the concept art with the set," says De Jesus. "Because his paint-overs would have gone through Sam [Raimi], they gave us the first solid approved look of a scene or a shot. We paid very, very close attention to those paint-overs. He provided lighting cues in addition to what they built." On set, the Imageworks team scanned and photographed each set and collected HDRIs at two heights for each lighting setup. "We had almost 1,000 HDRI pairs at the end of the shoot," Stokdyk says. "We could fully reconstruct what Deming lit for any set. But, you always art-direct a bit away from that or put special lighting in to make it look more artistically beautiful. On set, the DP is concerned with making a shot look beautiful. Real is automatic. But in visual effects, we have a dual challenge. We have to make the shot look beautiful and look real. If we cheat the lighting and put a rim light around our monkey, he is lit more beautifully even though the lighting isn't 'real.' So, it's something we have to weigh constantly. This is a fantasy movie with a flying monkey in a fantastic world. We wanted it to 12 CGW0313-Ozpfin.indd 12 look real, but also fantastically beautiful." Most of those fantastic environments were hybrids: A set for the near-ground, CG extensions for the mid-ground to background, and digital matte paintings in the far background. Working from Stromberg's paint-overs, a team at Imageworks mapped out the assets the crew would need to build. The first step was matchmoving. Layout artists positioned the stereo virtual cameras in the same position as the on-set camera, albeit inside a digital environment that matched the outlines of the set. "Layout worked in [stereo] 3D all the time," De Jesus says. "This film and Spider-Man were our first native shows. Because we had native stereo from day one and had the [digital] stereo cameras from the matchmove, there was no reason not to look at stereo in layout and in animation – sometimes even in effects as early as possible to get a sense of where to play up the stereo." Then the layout department looked at the previs for each shot and the images that Stromberg had painted over the dailies. "We had to reconcile how they cheated with what we could do," De Jesus says. "For example, they might have used forced perspective, but when we had to create the shot in stereo, it would break." Next, the layout artists set the stage for the animators, and ordered assets. "Our layout and model departments worked hand-inhand," De Jesus says. "Ordering props was an ongoing process: Modeling was constantly meeting layout's requirements." The final layout with the shot fully set-dressed with upgraded models would happen after animation. Flowers and Trees Modelers built all the props to work from any angle so the assets could be re-used, and they made the set extensions from scans of the sets so that the digital replicas would perfectly match. "We always tried to be efficient and build only to camera, but the reality is that this is the director's playground and directors like to move around," De Jesus says. "Although many models could be re-used, the texture painting was done more to camera. If we had shots only from a particular angle, we'd paint only those assets in high detail." To link the unique landscapes, the visual effects artists populated areas in each with similar assets, and used a similar layout for the ground cover. "We'd mix and match the assets, but they were the thread that takes us from start to end," Stokdyk says. "For example, we might have a cornfield next to the yellow brick road, with a unique lighting, layout, and feel. But, the flowers in the foreground would appear in three or four other places, as would the fence posts along the yellow brick road." The cloth and hair teams created the ground cover, the grass, and flowers. The layout team managed the trees, with effects adding dynamics. By the end of the film, the teams had created a forest library with 500 March/April 2013 3/14/13 12:11 PM