Legato and his Sony Imageworks team created a virtual 3D environment — clouds, sky and landscape poking through the clouds.

By way of example, Legato cites another project in his career when he had to recreate something that had really happened. For his Oscar-nominated work on Apollo 13, Legato says, “just because I could shoot the Apollo rocket on a stage didn’t mean I had the liberty to change the lighting that would have been there if I had been outside during lift-off. I had gone to the actual launch pad in Florida to check what the lighting was like out there, and when I shot the rocket model on stage I didn’t vary it from that at all. That made it more real. Even when you shoot something on stage, you live with the problems that you would have had if you’d shot it for real. Then when people look at it, they think, `That MUST be real,’ because if you’d had the opportunity to change it, you would have.”

The challenge with The Aviator was that they had to create both the aerial combat footage from Hell’s Angels and Hughes’ perspective as he was shooting it. Legato stresses, “We wanted to create the idea — and it’s a very subtle one — that our camera photographed him filming that moment. Although we could do anything we wanted to do with computer-generated techniques, we wanted to limit ourselves to the filming techniques of the day. Even though we did this big `CG scene,’ I was copying what the real planes did in the take that wound up in Hell’s Angels. You’re seeing clouds, the sky and the landscape poking through the clouds — it’s a virtual 3D environment much like what was there when Hughes shot his film. We emulated what was in his movie. Then we had an interpretation of what things must have looked like if you were in a third plane watching Howard film the scene. That’s the only liberty that we took with it.”

Legato notes, “We mimicked how this 60-plane armada flew, and it was pretty hairy. Back in 1927, Hughes built those planes. It was after the First World War and those planes didn’t exist anymore, so he cobbled together planes to shoot. For us to match Hell’s Angels, we had to alter our planes to match what Howard did back then. Hunter Grazner built the models for this show. They had all the plans and did a beautiful job. We photographed their model to use for textures on our CG model. We created a 3D version of Hughes’ plane and all the biplanes.”

When it came to the environment that races by beneath the Hell’s Angels dogfight, Legato notes, “the landscape was supposed to be Germany. But Hughes had actually filmed in Chatsworth, California.” Hughes’ choice — Iverson Ranch — was a popular filming location at the time, used for scores of films, including The African Queen. Since Chatsworth is now a heavily populated suburb of Los Angeles, that location would no longer work. Instead, Legato shot background plates at the relatively remote Catalina Island off the coast of Southern California. “It was similar to what Chatsworth looked like in Hughes’ time,” he says.

Legato captured footage that would provide the raw material for the virtual environment that the CG planes would fly above. “Basically, I went with a VistaVision camera and panned around.” Sony Imageworks created a 3D sky dome and wire frame geometry of the terrain onto which they would tile still images from the VistaVision footage. Legato observes, “If you were to be exact — like taking a Lidar scan of the area — you’d have the exact topography and you’d have the photographs from any one angle that looks exactly like that piece of topography. If you lay the photograph on the geometry, you wouldn’t be able to tell the difference. Using that idea, you now can spin the whole world around — as long as you have enough photography to cover a given area — you have basically a 3D photoreal mountain range. You can fly anywhere you want.”

Re-creating believable, cloud-filled skies that appeared in Hell’s Angels presented another CG challenge. When Hughes was shooting the original footage for the Hell’s Angels dogfight, notes Legato, “it took months and months of shooting and re-shooting to collect all the footage that they needed. They were on it for two or three years. When Howard didn’t like the shots because there weren’t enough clouds in the sky and he didn’t think it was exciting enough, he hired a meteorologist to predict when there would be clouds. then they would film.”