‘I’m very passionate about cobblestones now’

July 8, 2023

Behind the massive environment and vehicle build and complex compositing work by Rodeo FX for the Arc de Triomphe roundabout scene in ‘John Wick 4’.

Previously, befores & afters spoke to John Wick 4 production visual effects supervisors Janelle Croshaw Ralla and Jonathan Rothbart about the Chad Stahelski film.

This included discussion of the stunning Arc de Triomphe roundabout fight sequence filmed on an abandoned Berlin airport in place of Paris, and that features car to car gunfights, hand-to-hand combat amid the traffic and even a leaping dog.

Now, we’re going in-depth with Rodeo FX, the visual effects studio behind the sequence.

In this interview with Rodeo visual effects supervisor Javier Roca, we find out more about the Paris environment build (all the way down to the detailed cobblestone paved road), crafting a ton of CG cars, dealing with and retaining plate photography that included a multitude of car ‘bucks’, and, yes, how Rodeo’s leaping dog shot was an actual real canine shot on location.

b&a: What were your very first considerations on this Arc de Triomphe sequence when it landed at Rodeo FX?

Javier Roca: The first thing we did was ingest Lidars [carried out by The Yard VFX] from Berlin. Production created an imaginary roundabout with the same dimensions that were in Paris. The ground wasn’t the same as the one in Paris. We took the one from Paris and adapted it to Berlin. Why? Because we wanted to use the stunt cars, as many as we could, especially the hero ones, the ones that made more sense. For the ones that are running in the background, in most cases, we just got rid of them because it was much easier to use digital ones.

Ultimately, we always had to create a digital dummy car to project the lights and to get the reflections from whatever was happening around it, and put it on the stunt car. Which meant sometimes it was easier to do all of that with a digital car. Then, when we had everything aligned, we could start extracting cameras.

We spent a lot of time adapting the two grounds to make sure that when we were extracting those cameras we were as precise as possible. That was super important to make sure the matchmove was spot on. When we had the matchmove spot on, we would do some necessary re-positioning. In fact, the layout process was insane. This is the process of taking all the matchmoves and putting them all in the scene because we wanted to make sure everything was making sense.

With the first edit that we had, John Wick was doing a three-and-a-half times loop around the roundabout–there were so many shots. So we had to change the idea. The roundabout has a specific size and we had to work around that. We would show production a top view identifying where all the shots were–where they were filmed, and where they would end up in the sequence. In some cases we could cheat: ‘OK, it should be here, but maybe it could be here instead because then you’ll get a nicer background. Mostly we were quite accurate across the sequence. But it did take us months to go through that.

Once we had the cameras and layout, we started doing the first passes. We had so many cars. We counted around 1500 cars that were animated by hand. It was a little bit insane! There were shots where we had hundreds of cars, and then two different types of simulations for the cars that were getting in and out of the roundabout, plus the cars that were going around the roundabout. We had buses, too, and pretty much every single kind of vehicle–taxis, scooters, motorbikes, minivans–you name it. Once we defined the path of animation, we started rendering this environment.

The rendering was very complex. It was 113 shots. It was almost like doing a short animated film at 4K, with so many different elements. We had to render two different lighting scenarios for the artists to combine. So, we had Paris, which was always rendered fully. And then the Berlin ‘lights’, to make sure that those lights that they used on the Berlin location were also being reflected on the CG cars. Plus, the other way around, on the stunt cars, we were getting the lights of our CG Paris on top of them as well. The idea was that everything needed to be living under the same type of lighting conditions. Headlights but especially taillights and brake lights are a huge part of a car’s design, so we needed to replicate, or at least re-invent, these lights to be modern, LED vs halogen, taking into account the colour temperature depending on new versus old cars, have the right exposure while still giving lig/comp flexibility to adjust them…and not to mention indicators.

There were actually 99 light groups that we worked on for months as a team. We came up with a system so that, say if one car was breaking that light, it would be affecting three other cars. We would be able to trigger that and then get that reflection in the right place. Once we had that, it was a matter of taking it to comp.

b&a: I was curious, going back a little bit, whether you looked to any specific films or YouTube footage or TV shows of ‘nighttime in Paris’ to get a look and feel for how that area looks?

Javier Roca: We looked at hundreds of pieces of reference. We had a little bit of footage that they got from Paris, so that give us some information. One of the best references I found was one of those multi-camera array set-ups that they had for driving through the same locations that John Wick does in Paris. It was a 360 degree camera with all the angles. And it was a wet night, too.

b&a: You mentioned you received some Lidar and photogrammetry. What did that help you build?

Javier Roca: Well, we ended up creating another 200 meters around the roundabout into the neighborhood. I mean, they could have gone and done more of the chase and fights into all those streets if they wanted to! There’s so much detail. We have a library of benches with different types of graphics and stickers on them. The same thing with the traffic lights and stop signs, so many variations. If you zoomed into any of those buildings or homes, we even had modeled the inside of rooms, that allowed for parallax shift. We didn’t want to get into any kind of 2D matte paint. We just wanted to make it real.

b&a: What was also the approach to building vehicles?

Javier Roca: That was a really interesting process. They had a lot of scans from the cars that they were using in Berlin. Some of them the director didn’t like a hundred percent. He was very specific. They didn’t really even want super modern cars. We even had some vans from Poland in there from the 60s. The whole team was a little bit amazed by how eclectic the collection of cars was.

One challenge was that the stunt cars in Berlin didn’t have the vibration that you would normally have on Paris streets, because there were no cobblestones on the shoot. So, we had to do a lot of fine tuning to get something that worked with the ground that we built.

b&a: You mentioned cobblestones there. When I talked to Janelle and Jonathan, they both mentioned Rodeo’s cobblestone work. How did you approach it?

Javier Roca: I’m very passionate about cobblestones now. Selling the ground was very important. You’re constantly looking at it from so many different angles with so many different lights that are affecting it. Some areas are wet and some areas they wanted to keep as dry patches. We were going through leaving tire marks, too. It was also important what time of year it was, in terms of what kinds of leaves needed to be around, if it was Fall. How clean did it need to be?

We ended up leaving it as clean as possible and just focusing on providing as much detail as possible, especially for close-ups. I would say that the cobblestones are the most important assets that we built and the one that we put the most amount of work into.

b&a: In the cinema, I remember the audience roaring when John Wick was crossing the lanes of roundabout traffic, and just the fighting and missing some cars, and then maybe an assailant would pop onto the bonnet of a car. Tell me about putting that scene together. What was it like for you when you saw the plates for that which must have involved some car bucks that you’d need to replace?

Javier Roca: When I saw those plates, I said I need to find a car with the lights as low as that, with the same kind of illumination on the ground. That was challenging for us, as well, to matchmove that very specific shape. It was great for the stunt performance. It allowed them to jump, but not to get hurt. In some cases they were using real cars, and in some cases they were using these props. We had to use a very specific type of animation in order to fill that gap.

Sometimes we had to replace what was behind that car, because if you have a stunt actor behind one of these props, and you want to keep the performance, and you don’t want to make a digital, then you are attached to whatever that prop is doing. Sometimes it wasn’t fast enough, so we’d need to start doing some kind of re-time in order to make sure the impacts felt right. The cars that were easier to replace were the ones that had like a little bit of greenscreen on top.

b&a: Did you actually have to do many digi-doubles at all?

Javier Roca: No, no, no. It’s all real. John Wick is the only digi-double digital we needed for the inside of a car when he gets hit. But, Keanu was always driving his car, which was amazing. It helped a lot. I think when you start doing, say, face replacement, we can do a really good job but it’s never quite the real thing.

b&a: There’s a scene where the dog jumps along a bunch of cars, how was that achieved?

Javier Roca: That was a real dog they had on set jumping across some platforms. We just built the CG around the action. And if the dog was not jumping long enough, we’d make a longer car.

b&a: Can I give a shout out here to the people involved in matchmoving, tracking and roto, because, obviously you’re extracting sometimes moving and spinning cars, you’re extracting Keanu and the stunt performers, the camera’s moving wildly sometimes. Tell me a bit about that prep process.

Javier Roca: Yes, well, I think we have only two fully CG shots. Everything else is a combination of plate and CG. Every single process had their own iconic task for us–we call it the ‘John Wick factor’, you know, in another movie it would be a certain level of complexity, and in John Wick it’s ‘John Wick level’. We loved the fact that everything was shot practically, with real cars doing real actions, interacting with each other. That already sells the shots.


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