As director George Lucas planned out what he was going to do on Star Wars: Episode III Revenge of the Sith, he relied on a core group of 12 previsualization artists, who created over 6,500 computer-generated shots that showed possible approaches to various intricate computer-generated action scenes. He worked closely with them to block action, try camera angles and moves and experiment with what would work in the film long before shooting ever began.
The previsualization work was done by JAK Films, a sub-company of Lucasfilm set up specifically for the new trilogy. The artists began work on Episode III about a year and half ago. Many had worked on shots for the director’s cut of THX-1138, then rolled right into the Episode III previz, staying on the movie until the early part of 2005.
The previsualization process began in the picture editing room, where editors Ben Burtt and Roger Barton roughed out a preliminary cut using storyboard images and shots from old films, including the previous Star Wars movies. Reference clips from the cut were then sent to the previsualization department. “We translated those into 3-D shots,” says Dan Gregoire, the previsualization-effects supervisor for Episode III. “We started building sequences shot by shot. We have George’s ideas, our own ideas and ideas from the art department, but basically it comes down to George saying, ‘We have a space battle come up with something interesting.’ Then he’ll come back and give us revisions. After a couple of revisions, it’s approved and sent to the editorial department and we move onto the next sequence.”
Unlike many visual-effects departments in which individual artists work on a very specific aspect of a shot before handing it off to someone else, for Episode III, a single artist would own an entire shot or sequence from start to finish. “Everybody is multi-faceted,” notes Gregoire. “You have to be able to understand the full 3-D production process from start to finish. Storytelling is paramount being able to put one shot ahead of the next and understand how shots come together. You also need good, strong framing and composition.”
While Gregoire receives a lot of résumés from people who have been working at large facilities, he often finds that those artists have been doing nothing but rotoscoping or some other narrow specialty. “People get in these little niches and either don’t understand or don’t want to understand how their work impacts other people,” he points out. “Once you get into one of these big facilities, your mind can turn to mush because you’re doing one thing all day. I usually like to hire people from smaller companies that have less division in their labor force.” He also looks for artists who have just finished school, because they’ve come out of a boot camp environment in which they’ve had to make their own projects and they still have all the disciplines fresh in their minds.
One of the senior animatic artists on Episode III was Euisung Lee, who began working at JAK Films in 1999. Lee taught himself Adobe Photoshop and 3-D animation at home and was hired after David Dozoretz, the previsualization-effects supervisor on Star Wars: Episode I The Phantom Menace, saw part of a demo reel that Lee was in the process of building for himself. Lee worked on some of the final shots in Episode I, then stayed on for the next two installments. “I was really lucky,” says Lee, adding that he finds being plunged into a sink-or-swim situation the best way to learn something. “You have to get the job done when you know George Lucas is going to come in and say, ‘Where’s my shot?’”
According to Lee, the artists at JAK Films averaged two or three shots a day each, and if the shots were simple, they could do as many as four or five. However, very complex sequences that required a lot of problem solving could take much longer he spent about three weeks on one battle sequence alone. In all, he completed about 500 shots.
While the artists did use some existing CG models, including simplified versions of ships and other objects created at ILM for the earlier movies, they had to build a lot of their own assets before they could animate the sequences. Episode III also has a lot of new environments, which had to be developed by the JAK Films artists. “Since we’re the first ones to do it, we’re building it all from scratch,” stresses Lee.
The previsualization work was done exclusively with off-the-shelf software, primarily Alias|Wavefront Maya and Maya’s built-in renderer for 3-D and Adobe After Effects for compositing. “We don’t want to get mired down in a development process that may or may not work,” explains Gregoire, who points out that when people use proprietary tools, they may not explore other ways to do the same kind of work and may miss out on new features in commercial products. “If you want to be on the cutting edge, you may need to do your own developing. But for most productions, and especially previz, off-the-shelf tools are more than adequate.”
The computers used for the 3-D work were Windows-based PCs with AMD processors, and while JAK Films started the show using Macs for 2-D, by the end it was basically an all-PC shop. “Our PCs were just blazingly faster,” says Gregoire.
During Episode III, JAK Films switched over to machines using AMD Opteron 64-bit processors. “Each chip is attached to its own data pipe, so you don’t get a bottle neck,” says Gregoire. “It’s a much more elegant, fluid architecture, and it had a dramatic impact on our overall workflow. Just by switching to that alone, we were able to really cut down our production time in half, and we were able to start going home on time.”