Turning Glasgow into Philadelphia for the Zombie Apocalypse of World War Z
DS: I’d agree. I was quite impressed with how real everything “felt.” Even the zombie attacks. Not that I know what that actually looks like. The first thing that makes me raise an eyebrow in a vfx-driven film is when the physics obviously don’t work. Tell me a little about how you animated and made the zombies?
MJ: There are some rather unforgiving scenes we had to do. For example, where the girl leaps and smashes her head through the windshield of the RV and drags the guy out. When the guys is being savaged on the ground, that’s a fully CG zombie. We had several scenarios where we had to cut between a real performer and a close-up of a fully CG character that’s supposed to look like them, cut back to a real performer, then cut back to CG. It was almost a visual effects nightmare scenario. We were so keen to not have them look like CG “things” that we had to go to town to make sure the digi-doubles were as realistic as we could get them. We had a whole scanning pipeline and an onset photography pipeline. If I thought a zombie looked “cool,” we had a system using color-coded pieces of paper that I would give to the performer. If it was yellow, that meant that zombie should be recorded for reference. If it was green, they needed to be photographed and scanned. We had this whole separate village setup where we were scanning 50-60 people a day. We needed that because we just didn’t know what was going to play later in the movie. While I was onset making the movie, there was this whole other team scanning and photographing and moving people on turntables.
Antony and his team had spent a lot of time working on flesh and hair sims. For example, the girl who is biting on Ryan, she has long dark hair which is flying and flopping around. You want that sim to be realistic and natural, obviously, but you can’t have her hair flopping over the point where the director wants to see the teeth biting the guy’s neck. I can’t tell you how many versions of that sim I saw.
DS: It sounds like a ridiculously complicated and involved production.
MJ: It was. But I was never aware of it because it worked so well. Onset we had two units working. Each had a dedicated group of trackers, match movers, things like that. The movie style is all hand-held. We’re zooming all over the place. All things that make our lives a little bit tricky. Each camera had to have zoom encoders built onto it. All the data from that had to be logged. We had teams running witness cameras. It was a 24x7 operation. When we finished shooting, the scanning team rolled in and worked through the night, scanning locations everywhere from the town center of Glasgow to the old streets of Malta. It was pretty busy.
In post, I spent my entire life locked in a darkroom [laughs] so I never got to see just how many people we had working on everything. Key people were Andy Robinson, who was my digital effects supervisor, Thomas Dyg who was my environment supervisor, Antony Zwartouw who was the CG supervisor. We were unified in our desire to keep it as real and subtle and photographed as possible.
DS: As far as the environments, tell us about the scenes in Philadelphia and the New Jersey rooftop. Why would you choose Glasgow of all places to transform into Philadelphia?
MJ: Essentially, Glasgow stood in for Philadelphia. Glasgow is similar to Philadelphia in some respects. It works very well on a “first floor” level. You go anything above that, it’s not America anymore. You don’t have the tall buildings or the skyscrapers. I was trying to create a weird fusion between the two places that kept some sense of reality. When I got to Philadelphia, I had in my mind a logic of how the two locations would work together. This is the square in Glasgow…this square in Philadelphia looks very similar. We made sure that when we were adding in buildings, we were adding in Union Station and other buildings that in reality would be in Philadelphia. The Comcast Tower and things like that are all geographically in the place they would be if it were Philadelphia. Hopefully, if you’re familiar with the city, it will kind of make sense. Nobody would probably ever care, but there was a lot of work making sure it all properly blended together.
Aviv [Yaron] and I went to Philadelphia and spent a great week on various rooftops. We’d be on the roof of the town hall, office buildings, places like that, texture photographing buildings, building facades, skycrapers. Aviv was on an endless series of scissor-lifts. We were always closing down sections of the road on Sunday morning, driving up and down working at various heights. Originally, there was the thought that we’d do all these buildings in CG and we’ll do textures, things like that. But when I was in Philadelphia, I said to Aviv, “That building is right here. It’s real. Let’s just photograph it and use that.” The environments team did something incredibly cool, which worked out really well. Rather than do everything in Maya, the traditional 3D way, all the environments, from Philadelphia to the New Jersey rooftop, are actually created in Nuke, using the 3D capabilities of what is essentially a 2D package. Again, my big thing is to make the film look photographed. So, we’ll start with photographs! We’ll use reality as much as we can. Real buildings and real photographic textures. Then we’ll put them onto geometry that we create within a 2D package. It looks like a real building because it is a real building.