With Shane Black replacing Jon Favreau as director of Iron Man 3, there was a lot at stake for this post-Avengers action/adventure. First of all, Black wanted to raise the emotional stakes by giving Robert Downey Jr.'s Tony Stark an identity crisis; then there was the additional firepower needed in a whole new arsenal of remote-controlled suits to battle The Mandarin (Ben Kingsley) and geneticist Aldrich Killian (Guy Pearce) with his superhuman Extremis discovery.
On top of that was the intricate visual effects collaboration that was overseen by production VFX supervisor Chris Townsend that included Digital Domain, Trixter, Weta, Scanline, Method, Framestore, Luma and others.
"Shane Black wasn't sure of the VFX process and we talked about the reality of camera moves and the looks of things and keeping it subtle and not in your face," Townsend recalls. "So he left it to us to do our thing, which was a great creative freedom to push it further but at the same time maintaining that gritty sense of storytelling that Shane and Robert wanted to bring to the film."
The original plan was to have Digital Domain be the principal VFX supplier, but when the company went into bankruptcy, it was decided to split the workload among several companies, with Trixter taking on a more significant role. "It was too much of a risk not knowing the future of DD at the time so we took some of the work away and we gave them different shots with smaller sequences to work on," Towensend adds. "And then in Australia, Fuel, which was working on major sequences, also filed bankruptcy, so we had to deal with that as well."
It was important to recognize the design language that had come before and then take it a step forward to give viewers a new thrill. "We were planning to do 800 shots and wound up doing 2,000 shots," Townsend continues. "We started with a few suits and ended up building  suits, many of which are seen up close in the final battle, so the resources and complexity had to be immense. In fact, we didn't actually have a cut sequence for the final battle until the end of last year or early this year and at that point we had 500 shots in that finale to start creating."
A further complication was at the last minute it was decided to have a major story point change requiring the replacement of one of the actors, which meant they had to literally remove the actor and then shoot another actor on a green screen and composite him into the sequence.
And if that weren't enough, they brought back Pearce for another scene and by that time he had grown a beard so they had to digitally replace his jaw. "So we shot him against green screen, again with the idea of painting out the other actor and putting him into the sequence," Townsend explains. "First, we shot his face with multiple cameras pointing at him just so we had a reference of his performance and then shot him on a full green screen with the correct cameras lined up visually along with witness cameras. And Weta took all that data and it was decided it made better sense to do a digital Pearce. But because we had no clean plates and it was a fiery sequence, Weta wound up replacing that as well."
Design and handoff of the suits was tricky as well. DD did the creative development for 14 "foundation" suits, creating the complete assets for those suits that Weta and other VFX companies used in shots, and assets that other companies were able to combine to create additional original-looking suits.
DD had a small team embedded in Marvel's vis dev team. Marvel's art department created flat concept art, including front and back views or front-only views, and DD created full 3D versions of the foundation suits complete with textures and lighting. DD then turned those assets over to Marvel and Weta for use in their shots. One of the challenges of realizing the suits in 3D was in re-working the designs to ensure the suits had the correct physical aspects to allow them to move, changing proportions and component details for realistic movement.
For Weta and VFX supervisor Guy Williams, this collaborative handling of the suits was a very cooperative process that demanded a more rigorous examination of the animation process and required a "guide rig" system for suit transformation involving differing parts.
"Tony Stark's been busy building variations on the Iron Man suits for different attack mode situations, only there's a lot more variety," explains Erik Nash, DD's VFX supervisor, "including a suit designed for outer space that is reminiscent of the space shuttle with the white and black heat-tialed look; a stealth suit with a charcoal gray, carbon fiber look; and an undersea suit with a combination bronze/teal look. There's even one that has extendable claws. So it was a big modeling chore as well as a task assigning all of these materials for 14 foundations suits."
The biggest sequence for DD was an amusing rescue of falling passengers out of a plane called "barrel full of monkeys." It was a particular treat for Nash, who used to skydive. Early on, Townsend and Brian Smrzs (the 2nd unit director) decided to shoot with live actors free-falling for the most realistic look.
The actors in the sequence, who wore parachutes underneath civilian business clothes, are all members of the Red Bull Skydive Team, as is the freefall cameraman who shot the sequence with a helmet-mounted Red camera. The Team member playing Iron Man wore a red and gold jumpsuit and an Iron Man-like helmet. The Team jumped from 13,000 feet and did multiple jumps per day for nearly a week.
DD then replaced nearly everything digitally but the live actors. The 20-seat turbo prop plane was replaced with DD's CG Air Force One (complete with gaping hole, smoke and debris), and the underlying North Carolina ground plate was replaced with CG terrain that represents South Florida. DD artists also added multiple layers of clouds to the sky, one of which the camera goes through, and changed the altitude of the plane to support the idea that the crew was falling from 30,000 feet instead of the 13,000-foot altitude that was shot. A key part of making the sequence work was radically changing the flight path of the jumper playing Iron Man with a post move to make it appear as if Iron Man was flying up to the crew members and not just falling.
Meanwhile, Trixter was tasked with the fun and funny suit-connect sequences (including the beta test in the garage when Stark has difficulty summoning all of the individual pieces, and the later one when he's captured and can only summon the glove and boot).
"We studied all the other connecting sequences from the previous movies, but the special difficulty in our version was that Stark was moving all over the place and tracking was very tricky," recounts Simone Kraus, the animation supervisor that collaborated at Trixer with VFX supervisor Alessandro Cioffi. "At first, we had only five weeks to deliver footage for Comic-Con after the plates were delivered. Afterward, we started working on the movie version and re-did most of it."
There was also a romantic moment between Iron Man and Pepper that was quite a departure for the franchise. Trixter, which used a combination of Maya, Nuke, Mari, RenderMan, FumeFX, 3ds Max and Photoshop, tried to make us forget that it was man in an iron suit massaging Pepper, that you imagine Stark through the metal.
For late arriving Method (under the supervision of Matt Dessero), they built more internal suit pieces and broke them apart for shots involving water tower destruction, plant regeneration and Extremis acts of terror. Method acquired assets from DD, Weta and Framestore (which worked on Extremis-related action as well).
As for Extremis, the effect consisted of custom blend shapes. On average there were three blend shapes needed per shot to lock the actor's facial performance. The matchmoves were important because the Extremis effect not only contains a surface component, but also a richness that Townsend was after that comes from the deeper internal component of the effect, including an internal glow that is occluded by the bones and vascular system. Method used Maya, Vray, Houdini, Nuke, Syntheyes and Boujou.
"The great thing about the Iron Man films is their irreverence and a believability about who he is and what he can do," concludes Townsend.
There's definitely more Stark can do despite the appearance of a complete character arc for Downey. Marvel swears he'll be back. And there's even a Bond-like tag proclaiming "Tony Stark Will Return."
Bill Desowitz is former senior editor of AWN and VFXWorld, the owner of Immersed in Movies (www.billdesowitz.com), a columnist for Thompson on Hollywood at Indiewire and author of James Bond Unmasked (www.jamesbondunmasked.com), which chronicles the 50-year evolution of 007 on screen, featuring interviews with all six actors.