"What we were interested in at that point was what were going to be the technical 'gotchas.' They are the things that an artist can do with a flick of the wrist, that will take a team of five computer scientists six months to try and figure out how we are going to do it. Gotchas are things that are technically impossible to do. A good example from Episode I is when the script said, 'The Gungan army marches out to meet the Droid army.' One sentence. It took us 10 months to figure out how to do it. They were innocent lines in the script and they were certainly innocent drawings on the wall. You might say, 'Isn't that interesting?' until you try to figure out how we are going to get that to work."

The Number One Challenge -- Elaborate Costumes
"One of the first things that we noticed when we first met with George was the very elaborate costumes that these digital characters were going to be wearing. We were happy with where we had gotten with digital clothing on the first movie, but we realized immediately that clothing would be at the top of our technical challenges list for Episode II."

"In the Star Wars world, we have digital characters that are composited beside real people. In a film like Shrek, everything is animated. In Star Wars, we have digital characters living in the 'real world.' The audience can compare Natalie Portman's beautiful costume to Yoda's robe in the same shot, but Yoda is digital and his clothing is not real. It's virtual. The audience has to see them as equal. It has to have the right weight, the right billow, the right follow through. The audience has to believe that these two characters are existing in the same space at the same time. If they don't, we have failed as special effects artists."

"It's a very high bar to get over. We walk around all the time observing people wearing clothes so we have a very rich understanding of silk, burlap, leather and how other fabrics look when they are moving. When we apply that to digital characters we have to be amazingly accurate. That was our number one technical problem."

The photo-realistic backdrops in the Clone War were all created digitally. © Lucasfilm Ltd. & TM. All rights reserved. Digital work by Industrial Light & Magic.

Challenge Number Two - Digital Environments
"The next thing we focused on when we saw the beautiful production paintings of these worlds was: how elaborate were the cityscapes and the scenery going to be in this movie? At that point, we were informed at how little was actually going to be built on the stages in Sydney. John [Knoll] and his group of people began to work on how we could improve our digital environments. John and his team worked for months trying to perfect that."

"One sequence ILM is proud of is a chase through a cityscape early in the film. At the other end of the spectrum, Ben Snow, another one of the visual effects supervisors, worked on the Clone War. He created photo-realistic rocky environments including canyons, buttes and plains."

Creating realistic movements and reactions are key to making digital action sequences like this one from the Clone War credible. © Lucasfilm Ltd. & TM. All rights reserved. Digital work by Industrial Light & Magic.

Challenge Number Three - Rigid Body Simulations
Rigid body simulations is the creation of believable weight and gravity on objects that are falling and exploding. Coleman says, "Imagine that you have a clone who is running along and gets hit by a concussion wave. He has to fall and 'clatter' on the ground. That's very difficult for an animator to animate, to get the right bounce and weight without spending a great deal of time on it. The team that worked on the clothing simulations came up with solutions so we could have vehicles exploding and pieces flying off them or droids hitting the ground and clattering. We used our new software to create realistic reactions every time two digital objects hit each other. It's amazing how many times that shows up. George knows his audience."