Recreating The World Trade Center and creating Visual FX for The Walk

Recreating the towers offered production designer Naomi Shohan and visual effects supervisor Kevin Baillie their greatest production challenge on The Walk. Ultimately, their work is a combination of an extremely large stage set and months of digital recreation.

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“We were not able to shoot between the two towers of the World Trade Center, of course, because, sadly, they don’t exist anymore, but we were able to replicate them in a way that I think is an enormously loving homage to those buildings,” says Joseph Gordon-Levitt. “Bob became obsessed with those buildings, with all the details, and in that way he mirrored Philippe – because Philippe became obsessed with those buildings in 1974 when they were first being built. He could tell you all the different elevators. He could tell you the dimensions of the height and width, and how much distance was between the towers, from corner to corner. Seeing Bob carefully and lovingly bring these buildings back to life was really moving.”

The first challenge came in deciding what to build practically and what to create digitally. “We had to figure out what square footage of the roof set would produce the maximum number of shots, knowing that there would be quite a lot of shots,” says Shohan. “We wanted to be faithful – more than faithful. We wanted to celebrate the towers, the scale of them. If you’re not aware of the place, you can’t possibly appreciate the enormity of the deed.

Relying on the original blueprints for the Trade Center, Shohan designed and built an enormous, 40-foot-by-60-foot corner of the South Tower, where most of the action takes place as the story stays with Philippe during the caper. Though the filmmakers would need to film action from the North Tower as well, they could make due with only one corner, because the two towers were largely mirror images of each other; Shohan could simply strike the stage dressing on top of the roof and re-dress it for its opposite corner.

Shohan’s team built a structurally sound roof – a necessity, because due to space concerns, the most practical place to build the 110th floor (a key location, where Philippe and Jeff hide out for hours) turned out to be right underneath the roof set.

In the end, essentially, Shohan and her team recreated one-quarter of the Trade Center’s 200×200 roof. With creative camera angles, this was often enough. However, to recreate the rest of the roof, the towers, and 1974 New York as seen from nearly 1400 feet in the air, Baillie and his visual effects team at Atomic Fiction brought the project home.

For the Tower, Baillie and his team had access to the original blueprints for every single floor in the World Trade Center, as well as countless reference photos. However, he and his team faced an unexpected challenge. “The Tower itself is a deceivingly complicated thing to make look real,” says Baillie. “It’s so geometrically simple, with those straight lines that go all the way down to the ground, but if you build it perfect, it just looks fake. We had to build the whole thing, and then figure out what the right amount of messing it up was going to be – slight misalignments between the panels, making sure the gaps between the panels wasn’t exactly the same. We also built about 30 floors of interiors, so if you look carefully, you can see desks and chairs inside.”

Even more challenging, Baillie and his team rebuilt a historically accurate representation of New York in 1974 – as seen from 1400 feet in the air, between the two towers. “New York in 1974 looked very different from what it looks like today,” says Baillie. “We did take a helicopter and flew above New York for two days to gather real life reference footage of what the city looks like now, but at the end of the day, what you see in the movie is 100% digitally recreated.”

For reference, Baillie and his team used any reference from the time that they could find, from images on the internet to archival photos in books and libraries to original blueprints and beyond. “There’s a really cool website that has a slider – you drag the slider to 1974 and any building that is new since 1974 is blue on the map,” says Baillie. “It was kind of a cheat sheet for us. At the end of the day, most of the reference photos are just that – reference – so our artists used those to build buildings in the surrounding vicinity completely digitally.”

For the most part, Baillie’s team did the math on each of the buildings to make them accurate. “Even buildings that didn’t have blueprints, we still had the stats on how tall they were,” says Baillie. Even the details – the size and configuration of the windows, for example – is based, whenever possible, on their research, and by “extrapolating intelligently” on the few buildings that no longer exist and had no ideal photo reference from the time.

For the most part, Baillie’s model is meant only to be viewed from above – Petit’s point of view during his walk. However, because Zemeckis planned a few shots from below – for example, from the World Trade Center Plaza – these areas of the model are complete and ready to be explored, as if you were walking around the city.

In the end, recreating the structures of the city and the Towers took Baillie’s “construction team” of 15 people three months to complete – four man-years’ time – after which a team of more than 100 artists spent five months integrating that digital world into the green screen footage from set. “There were definitely times when it was emotional, for both myself and the crew,” he says. “As we went through the reference photography, we saw a lot of imagery from 9/11, because those are obviously the latest images that you can find of the towers. So I think we felt a great sense of responsibility for portraying the towers in a way that was honest and also honored them.

“The other emotion we felt was pure excitement,” Baillie continues. “It really hit me, after we finished shooting, I spent two days in a helicopter flying right over Ground Zero at 1400 feet – we were hovering exactly where it was that Philippe was walking on the wire. It makes the hair on the back of my neck stand up, just talking about it – I’m literally in the place where this guy did this walk, with no safety gear, I’m looking down, and I’m just awestruck. It was really great to get that experience from the reference imagery that we were able to capture, but also that emotional sensation, that thrill of heights, and danger from that high up, and we made sure that every shot we have in the film gives that same sensation. I honestly don’t think the visuals that we have in the film would have been as good if I hadn’t been there to feel what that felt like.”

The Visual FX

In addition to recreating the World Trade Center and the City of New York, visual effects supervisor Kevin Baillie had many more responsibilities to make The Walk as seamless as possible.

For the walk sequence itself, Baillie says that as impressive as Gordon-Levitt’s feat of learning to walk the wire was, visual effects were able to give an assist in two ways. “For the simpler stuff, Joe did the actual walk himself, which was amazing,” he says. “For some of the more complex stuff, like when he lies down, or when he has the pole over his back, the wire was nestled into a 20-foot-long green steel beam. When you look at the actual footage, he’s walking on a six-inch-wide plank that has the wire in the middle of it – but when we removed all the green, it looks like he’s just standing on a wire.”

Of course, the real-life Philippe Petit had years of training to perform his coup; Gordon-Levitt had eight days. Certain, technical moves on the wire were beyond his ability. For these, the filmmakers employed a double, Jade Kindar-Martin, who is one of the most accomplished high-wire walkers in the country – a man who married his wife on the high wire, and who, in a fabulous and serendipitous coincidence, was trained by Rudy Omankowsky, Jr. – the son of Papa Rudy, who trained Philippe Petit. “We took a photo and put both Philippe and Jade on the phone to Papa Rudy, Jr., because he was so excited that we were making the film,” says Starkey. “Jade continued the training of Joe that Philippe had started prior to filming. On Saturdays, they came in, continued to train and Joe got proficient at crossing the tower.”

Kindar-Martin also performed the wire-walk stunts that were beyond Gordon-Levitt’s abilities. Visual Effects was there to make his performance seamless with Gordon-Levitt’s. “There were a few truly complicated stunts that only a true wire-walker could do – like kneeling down on the wire and saluting with the hand, or the more complicated turnarounds, or juggling flaming torches on a slack rope,” says Baillie. “As talented as Joe is, those are things he can’t do. Those were performed by Jade, the stunt double, and we did a face replacement. We scanned Joe’s face in 43 different poses, so we could record all of the muscle movements that his face is capable of. We could mimic the look of concentration and determination that Joe would have if he was doing that action on the wire.”

The Walk was shot in 2D and converted to 3D by experts at Legend3D. Though it wasn’t that long ago that 3D conversions carried a negative stigma, Baillie now says, “I’ll never do a movie any other way. It’s such an amazing process, and I think it looks better than shooting a movie with two cameras, because you can sculpt the depth to help the audience feel the particular emotion that the director intends. You’re not grounded in reality – you can do what human eyeballs do anyway, which is to filter information and create a modified version of reality that your eyeballs then pump to your brain.”

The film was conceived as a 3D film, and Baillie notes that the entire team was careful, from pre-production all the way through post, to make decisions that would work well in 3D. “For example, we used wide depth of field for focus – we kept everything in focus as much as possible,” Baillie explains. “Bob was also excited about using long, sweeping shots, rather than quick cuts. Usually, a film will have about 2000+ shots, but The Walk only has 826. And Bob did that intentionally, so that the audience has a chance to really take in and explore the 3D environment that they’re seeing.”

The Sets

To create a background of 1974 for The Walk, production designer Naomi Shohan aimed for simplicity in design, a credible world for the character of Philippe Petit to appear against. “We weren’t in the real places and we weren’t in 1974, so we did our best to evoke the spirit and look of the real places,” says Shohan. “We made an attempt to be faithful.”

Which is not to say that the film is not designed. Shohan’s approach was to aim to evoke the beauty of Petit’s movements, his grace and form, by creating the space for him to move. “There were some reference photos that I saw of Petit in his New York apartment, talking with his friends; there was just a table and a wall and a picture and he’s moving through it. He’s very graceful – the ultimate figure in space,” she recalls. So, she concluded, “This is a film about a man in space. I hoped that the simplicity of the design would leave room in the frame for the human being to be almost a silhouette as he moved in space.”

To achieve that, she made monochromatic choices in her color palette. “I wanted the colors to be quiet and recessive,” she says. “If there was going to be much color, I preferred that it be in the wardrobe.”

The one exception, of course, was the circus. “A long time ago, I went to a circus in the South of France. It was a little, one-tent circus. It was the most charming circus I’ve ever seen. I remembered that and wanted our circus to be more like that, an old, traveling European circus, more like Cirque du Soleil in their infancy than Barnum & Bailey – a mom and pop, old-school, one-ring circus.”

Shooting on location in Montreal, the filmmakers were given access to a block and a half of cityscape that they could send back in time 40 years.