When John Knoll swings around from his desk, he comes face to face with a wall-sized line chart that shows the progression of the 1,700 visual effects shots he supervised for Star Wars Episode III: Revenge of the Sith. The lines on the chart start near the floor and slant smoothly upward. When the last shot wraps, they’ll reach head height.

Knoll spends mornings in dailies and looking at individual shots. The afternoon is a mixture, from checking the stage to looking at review requests for shots people want to run overnight.

"A show like this has to be scheduled like clockwork," he says. "You have to make sure there are no kinks in the pipe, that everything is ready when it’s supposed to be ready." He turns to answer a review request that appears on his monitor with footage of Obi-Wan riding a lizard-like creature. The TD needs to put a digital light saber in Obi-Wan’s hand and wants to know if he can fake it or if he needs to create a CG hand so the fingers will close around the light saber. Knoll quickly types a message telling him to create the CG hand.

To the right of his desk, a four-channel motion-control system is planted squarely on the floor. If you drew a timeline between the heavy metal box and the wall chart, you’d trace Knoll’s 20-year career in visual effects.

Knoll built the motion-control system while at USC film school to put an Oxberry animation stand under computer control so he could create a slit scan experimental film. It was 1984 and the computer was an Apple II. Two years later, he was a motion-control cameraman at ILM.

"I’d say my M.O. has always been: Develop a hobby, get really good at that hobby, and turn it into a profession," he says. It turns out that his hobbies have influenced the way visual effects are created by other professionals, too.

Take Photoshop for example.

Two years before Knoll arrived at ILM, Lucas had sold Pixar and started a computer graphics department. During a tour of the CG department, Knoll saw a demo of Pixar’s Image Computer.

"The demo wouldn’t impress anyone today, but it knocked my socks off," he says. "They loaded a David deFrancisco laser scan of a film element onto the Pixar frame buffer and sharpened it. The implications weren’t lost on me. The world was open to massive innovation. But the hardware cost thousands of dollars."

Not long after, the 23-year-old went home to Michigan, where he saw the image-processing programs his brother Thomas was creating on a Macintosh for a doctoral thesis in vision systems. The rest is history.

When he and his brother were about a year and a half into creating Photoshop, Knoll moved into ILM’s computer-graphics department and The Abyss (1989) became the first feature film to use a version of Photoshop. But by then, Knoll already had a new project in mind – digital compositing.

"The optical process was a slippery fish," he says. "But with a digital composite, when you fixed something it would stay fixed, and you could keep making the shot better without degrading the elements. There would be no limits."

When a shot came up in The Abyss that would have been a nightmare to composite optically – the door closing on the pseudopod with a splash – Knoll and Jay Riddle jury-rigged a way to do the composite digitally using the Pixar Image Computer and an Exabyte tape drive. The tape drive was necessary because the Pixar had only 16 MB of memory in its frame buffer – enough to hold one high-resolution frame.

"It was kind of a crazy rickety process," Knoll says. "But it was really exciting. No one had done this before."

By 1990, Knoll had become a visual effects supervisor and when he took the effects helm for Star Trek: Generations in 1993, he turned another hobby into a profession. "I was bidding a shot where the Enterprise goes into warp drive," he says. "The numbers I got back from computer graphics were depressing because it was bit like we were doing a dinosaur movie. I’d been playing around with commercial tools, so, as an experiment, I decided to do the shot myself." He built the model in Form Z and created the shot on a Macintosh one weekend using Electric Image and After Effects.

"I became enamored with the idea of simple shots with simple tools," he says. So, when Star Trek: First Contact showed up, ILM’s Rebel Mac group was born. The unit moved from Star Trek to Star Wars Episode I, for which they created the space battles, and on to Episode II. Eventually, some Rebels left and founded The Orphanage.

"The Rebel unit succeeded themselves out of business," Knoll says. "Now, ILM’s computer graphics department has tools for keeping simple work simple."

Given Knoll’s M.O., you might think he’s moved onto something else. You’d be right. Remember that old motion-control system beside his desk? He brought it into his office for a reason – a little hobby project that he can’t talk about yet using that system and a digital camera. Given Knoll’s career trajectory, chances are it, too, could change the way people create visual effects.