'Iron Man' crew had desired effects

Visuals designers found success aiming for realism

Director Jon Favreau issued a mandate to "Iron Man" senior visual effects supervisor John Nelson: Keep it real. So Nelson, an Oscar winner for "Gladiator," strove for photorealism in Paramount's blockbuster comic book film, mindful that the characters had to be kept front and center.

When Robert Downey Jr. suits up in his metal exoskeleton, the gleaming body armor is a combination of computer-generated versions, created by lead VFX house Industrial Light + Magic, and practical, built by Stan Winston Studios.

"We would always try to do as much as we could practically, but we replaced most of it with CG because it's mostly an action movie," Nelson said. "We had practical stuff to ground us, and that made it that much better."

The ILM team, which included internal VFX supervisor Ben Snow ("Star Wars: Episode II -- Attack of the Clones") and animation supervisor Hal Hickel ("Pirates of the Caribbean"), developed several suit variations, including different sizes and flying abilities.

In some cases, character performances were captured using iMoCap, ILM's proprietary motion caption system first used for the CG Davy Jones character in the "Pirates" films. For "Iron," Downey or stunt people were used depending on the needs of the shots.

Some of the motion capture was filmed at Perris Valley Skydiving in California, where the motion of skydivers was captured in a wind tunnel. For Iron Man's flight, a combination of flamethrowers and CG flames were used to create realism.

To allow Downey to act inside the exoskeleton, the team created a virtual display with which the actor could interact. Those shots were created at VFX house the Orphanage.

The climactic final showdown has Iron Man and villainous Iron Monger battling in three key locations: a freeway in Long Beach, Calif.; 80,000 feet in the air; and on a rooftop. In the complex sequence, the aerials were mostly CG environments. Some plates were shot, for instance, from a Learjet diving with a nose camera at dusk. Miniatures also were shot for the final sequence.

A lot of research also went into the level of reflections on the chrome suit, particularly in the night scene.

Shrinking schedules have become an ongoing challenge in the VFX industry, but Nelson insisted there are two sides to that coin.

"Both are good and trying," he said. "With big action movies like this, people are always trying to shove as much into them as possible. It makes delivery difficult. The other side is, if you are in post and you see you can make something better, you want to do that."