The airport battle at the heart of “Captain America: Civil War” was conceived as a choreographed ballet by the Russo brothers: Captain America (Chris Evans) has gone rogue and tries to get on the Quinjet, but he’s met by Iron Man (Robert Downey Jr.) and the two teams face off, each with their uber objectives. But then this splinters off into mini-beats with Black Panther (Chadwick Boseman) trying to kill Winter Soldier (Sebastian Stan) and Ant-Man (Paul Rudd) and Spider-Man (Tom Holland) just trying to fit in and becoming the wild cards.
“We were trying to figure out who’s fighting who, the strengths and weaknesses of each superhero, but it’s a non-lethal fight ,so what can we do to show that?” offered Industrial Light & Magic VFX supervisor Russell Earl. Everything was shot on green screen in Atlanta and ILM added the virtual airport. There was a previs cut by The Third Floor along with cuts by the stunt and editorial teams, and ILM added a few wide shots to provide more scope.
What turned the sequence around, however, was having Ant-Man turn into Giant-Man and Spider-Man recalling the strategy from the Battle of Hoth in “The Empire Strikes Back” by wrapping his web around his legs to bring him down.
“He grows to 50 feet and that was a big mass and weight change from an animation standpoint,” Earl suggested. The Russos decided that he should stagger like a drunken baby and Rudd moved around in a mocap suit like Godzilla. They worked on further mocap retiming with different beats for grabbing, running and jumping, and used various tools to stitch the performance together and then augmented it with keyframe animation.
The big challenge, though, was introducing Spider-Man into the MCU. Like all the other Avengers, his web-slinging needed to be grounded in real-world physics. ILM did numerous tests in collaboration with the sibling directors. “They wanted him to be a kid just getting used to his powers, so he didn’t hit the perfect pose,” added Earl, who previously worked on “The Winter Soldier” as well as “Ant-Man.”
“If he’s swinging, how does he get from point A to point B? Physically, we pumped the legs and evaluated shots for believability,” Earl continued. “We calibrated from too over the top or too perfect and added imperfections.”
At first, they alternated between shooting a stunt performer and Holland in the suits. They used witness cameras for Holland and studied parkour for reference. But half-way through production, they decided it was easier to go full digital for the Spidey suit with muscle rig and muscle sim as well as cloth suit and cloth sim. They started with blue spandex and red satin fabric and added a carbon fiber textural pattern and a raised printed pattern on top. They played with the slide to stretch ratio for the fabric so that it looked like a real person talking under the mask.
They shot Holland with two head-mounted cameras for facial performance to drive the movement under the mask. Animation was added to the eyes and jaw movement underneath the suit for greater expression and augmented with keyframe to make it read better.
For Black Panther, they also went from a practical suit, with vibranium thread woven into it to full CG to make him more heroic-looking. They also steered clear of any Batman likeness.
“Proportionally, it was difficult,” Earl admitted. “So we made the helmet smaller, the chest bigger, the shoulders broader and the waist narrower. Animation wise, we gave him cat-like agility and keyed off of stunt performances. Even in close-up fighting, he’s been fully replaced by a CG version. But it’s seamless. He’s a badass character.”
“Captain America: Civil War” is now in theaters.