The hardware change had another important effect: because the process was now so much faster, Lucas began to sit with the artists and work with them directly, something that had never happened before. “That was quite unusual,” says Lee. “When we first learned that George was coming upstairs, it was a little tense, really quiet. It was a lot of pressure. But he started coming up every day, and after a while, it wasn’t a big deal anymore.” At times, he adds, Lucas would talk with them about the ideas behind the movies and about the Force — a dream come true for the Star Wars fans on the crew. He would also bring his lunch and a bottle of soda every day, and after a while, the artists started to collect the bottles, joking that they would sell them on eBay after the movie.

Lee and the other artists found that by working with Lucas, they learned to think more like directors and editors. “When you have him next to you, he points out what happens in the context of story,” observes Lee. “Focusing on one shot and making it look pretty may not be as important. Sometimes, George would approve a sequence, but sometimes he would say it’s distracting, not helping the main story. You’d try to not be attached to your great idea.”

Although the hardware change accelerated what the artists could do, they still had to work light and not get too embroiled in minutia. “Obviously animatics have to be done really fast,” says Gregoire. “You can’t spend too much time on polishing them up and making them pretty, like final shots. They’re really low-res.” For the most part, the models were built using polygons, making them lighter and easier to handle than NURBS-based (non-uniform rational B-splines) models would have been.

Texturing and lighting also required a balance between keeping the process fast and making the results detailed enough to indicate what the final shot would look like. “We worked with the art department to create textures and surfaces, and we lit the sets for time of day, which created certain moods and feels,” says Gregoire. The artists used mainly three-point lighting, working with Maya’s built-in lights.  “We tried not to get overly complicated, because we have pretty strict deadlines.”

All of the previz files and resources were sent to ILM, so that they could be used as references. Although ILM artists rebuilt the models, they were able to take paths, animations, framing, lens selection, subjects’ positions in frame and other attributes right out of the animatics and build on them in Maya and After Effects.

Once shooting began, previsualization ended, because there was no longer enough time to go through the whole approval and update process with Lucas. But the artists kept working, changing their focus to what they called pre-postproduction. As the live-action sequences were shot, they would do a speedy effects pass on them so that the shots would be easier to look at and judge in the editing room. “It gave George something to cut together,” says Gregoire. “We do everything ILM is going to do, but we do it at video resolution -- and quickly. It involves rotoscoping, building sets, extending sets, adding characters and filling out the plates.”

Lee says they also did less-obvious image manipulation.  “For George, shot footages are another starting point,” he explains. “He manipulates plates in an editing bay to change shot composition and angle of view, and even fabricates new shots by combining multiple plates. Our job is to complete those manipulations by adding proper background and visual-effects elements”

Gregoire says that by doing these pre-postproduction shots, they also helped Lucas offer better guidance to the artists at ILM, making it possible for him to tell them what was actually being used in the cut, so that they could skip the rest, which saved time.

He adds that while studios and producers often resist the idea of previsualization because it means adding another line item, the concept is becoming more widespread as they realize that it could save money. “Rick McCallum, the producer, is a total convert on previz,” says Gregoire. “He figured that it saved the production about $10 million.”

Gregoire sees previz headed toward a more mobile, guerrilla-style approach, something that he tried out after Episode III with Steven Spielberg on War of the Worlds. Working on an Acer 3400 laptop as he traveled with the production crew, Gregoire would previz shots in a trailer or in a tent off to the side of the set. “Steven would pop in whenever he had a free minute, or he’d give me a new idea and I’d run it out a few hours later.”

While the crew initially had no idea who Gregoire was, they soon saw how much the previz was helping Spielberg, and they began to take cues from it as well. “It really was the vortex of a lot of things that happened on the picture,” the previz supervisor notes. “By the end, everybody was calling on me, ‘Dan, what happening next?’” He says that the translation from digital to reality is always a little difficult, and things do change but the previz shots that he made for Spielberg formed the foundation of what the crew would do. That made it possible for cinematographer Janusz Kaminski, ASC and the camera operators to start planning what they would do for various shots. “It gives everyone a place to start,” he admits.