Breaking down key moments from the Flash/Batman/Supergirl vs Kryptionans battle.
Andy Muschietti’s The Flash features a third act climax in which Batman, Supergirl and the two Flash characters team up against Zod and his powerful Kryptionan forces at a desert site near Edwards Air Force Base.
Wētā FX, working with production visual effects supervisor John ‘D.J.’ Desjardin and production visual effects producer Tamara Watts Kent, created the VFX for the battle scenes.
The work required extensive world building, digital double creation and significant animation and effects to extend live-action stunts and photography captured on a soundstage.
befores & afters sat down with Wētā FX visual effects supervisor Kevin Smith and Wētā FX animation supervisor Simeon Duncombe in Wellington to find out more.
Gearing up for the battle
b&a: Kevin, what were the first conversations you had with production about this third act battle?
Kevin Smith: I was lucky enough to be on set when they were shooting a lot of it. They shot it all on the soundstage, while the sequence is set outside in the desert. Andy had a pretty good idea in his head of how this dos-a-dos, figure of 8 move, would happen. Stitching all that together and making sure there’s a consistent frame of reference for all the shots–that’s where we picked up the creative heavy lifting from the client. It was my third film in a row with D.J., so we’re to the point where we effectively have a shorthand now.
Simeon Duncombe: To clarify, the dos-a-dos was our codename for the action where The Flashes finally team up and do that big move across the battlefield to take out the Kryptonians. There was a lot of staging to figure out that particular part of the sequence. Plus, of course, we then had to tie in the geography of our other heroes, Batman and Supergirl, to make it feel like a big team effort. A lot had to be figured out because it was not represented in the plate photography, so there were some pretty big holes in the edit we needed to fill. This was my fourth film with DJ, so he was confident to just let us run with it and fire back ideas and material that would help inform the cut.
b&a: What did they shoot on?
Kevin Smith: They shot on a stage with blue walls and a brown painted floor. They had an idea of the overall beats in the script. They would have Ezra and Ezra’s acting double acting together. They would then record the other Flash performance in Eyeline Studios’ stage and then give us a whole CG head, meaning that they didn’t shoot one Ezra and then another on the bluescreen and brown painted stage – Ezra did all the secondary performances in the Eyeline booth.
For many shots, we ultimately kept just the eyes and mouths as we effectively replaced the suits the entire time. It got to the point on the shoot where they really weren’t even wearing the suits because they knew we were going to replace them. They’d sometimes just wear the helmets and mocap or gray suits.
b&a: How did you start the process of working out story beats? Did that involve going onto Wētā FX’s own mocap stage?
Simeon Duncombe: Andy (director Andrés Muschietti) always liked to understand geography, so he would often provide sketches of staging ideas. Having those goalposts gave us somewhere to start, then it was just a matter of roughing out that first blocking pass that hit the key beats Andy was after. We would only spend time on the stage when we were confident with where the sequence is headed and what actions were required. Sometimes, however, a lot of staging and action questions found their answers on the stage. Working in a physical space with performers and talking things through was always a great way to problem solve.
b&a: What did you need to build? Tell me just about the environment, in particular.
Kevin Smith: Well, having just come off Hollow Earth in Godzilla vs. Kong where the environment is all made up, it was actually really nice to work on this sequence because it’s set in a real place. Really early on, I started playing around with a bunch of satellite imagery. We got the DEM (Digital Elevation Models) and some true color imagery. Our camera department has a lot of really great tools where you can take all that stuff and register it to each other, because with different satellites you get different patches. We started out with just the Antelope Valley, which was cool because my dad lives there, so I’m super familiar with that part of Southern California.
We also needed some shots in plains which meant we needed to extend what we saw to cover pretty much all of Southern California, especially when we get up high. We built all of that at DEM level. As we got closer to Edwards Air Force Base, we would up-res in patches so that by the time we came to building a shot, we had great detail.
The heroes arrive
b&a: How did you do that shot of Supergirl going through the missile?
Simeon Duncombe: That was one of the first scenes turned over to us. We started that shot early but it was still something we returned to work on a year later to properly final. The fun bit was working out how to peel off the missile around her. With the big speed ramp across the shot, we really paid attention to her posing and getting the cape to slow down in a nice way.
b&a: Was there a live-action element of the actress?
Kevin Smith: There was a plate for the pull-up moment. We knew then that our CG Supergirl was going to have to hold up really, really well. We tried to make that plate work but in the end we mostly relied on the digital double.
b&a: There’s a very heroic sliding shot that was seen in many of the trailers, with Flashes and Supergirl screeching to a halt. How was that accomplished?
Kevin Smith: That is an example of something that they shot on stage on wires. We kept most of it – we may have had to replace the suits, but performance-wise, it’s all there. We just had to extend the length of the slide. There was a lot of work in having them come out of the jet for that scene, coming into the slide.
Crafting a dos-a-dos
Simeon Duncombe: The dos-a-dos was something Andy had figured out. He gave us a sketch of the staging he was after, where the different Kryptonians would be placed throughout the battle field and what moves the Flashes would use to take them out. We had some funny codenames in there, like ‘elegant kick’ and ‘wrestle boost’ to mark those moments.
Kevin Smith: It was a bit of a head-scratcher first. They turned it over and kept referring to it as a “dos-a-dos”, but until Andy drew it we weren’t exactly sure what it was.
Simeon Duncombe: We went down to our mocap stage with a couple of animators to get our heads around the blocking. We would start fleshing it out, then through the blocking process tried to refine the pacing to build up to a nice, big crescendo. Originally, it played out in the cut as one long sequence, but it’s now intercut with other beats from Batman and Supergirl.
b&a: In that sequence, there’s time ramps and speed ramps throughout the whole thing. How do these things impact animation and visual effects?
Kevin Smith: There were three speeds we had to deal with. There’s the speed of the world, which is always normal. There’s the speed of Flash, then there’s the speed of the camera. You could have Flash moving fast with respect to the world with a normal camera for Flash, say. Then there’s Flash looking like he’s at normal speed and the background’s frozen. Then you have an actual speed ramp on that, so suddenly Flash speeds up. Then the world comes back, or sometimes Flash would slow down and you change the world that the camera lives in. Ultimately, the relationship of the camera to Flash and the real world changes all the time.
b&a: I imagine one of the big challenges is connecting to live action plates. Were they shooting any Phantom plates, for example?
Kevin Smith: Not really. Usually, we were just trying to do a really severe speed-up and slow-down on plates. They did shoot stuff at 48, 96 and 128 fps. I think even 128.
b&a: I was curious about ramping up and down and how that impacts VFX, too?
Kevin Smith: The hardest thing was all of the background stuff. You can ramp up a sim – from slow to fast is easy – but you can’t take a big simulation, like all the oil fire plumes of smoke that are trucking along at real-time, then suddenly have that slow down. You have to sim it with the time ramp in it, which is hard as the client may want to adjust that later. You can’t always be re-sim’ing it every time they may want to change the speed, so we eventually came up with a way to resample the simulation so that we could change the time warps on the fly, and all we had to do was re-render.
Coping with capes
b&a: How did you tackle cape animation?
Simeon Duncombe: In the case of the Batman cape, it had to do a lot for different performances, because he goes from a glide to realistic grappling to being thrown onto the ground.
Kevin Smith: The creature and animation pipeline guys came up with a new system where it didn’t have to just be animated or sim’d. We could animate key poses, then run a sim on top of that that, which would do its best to hit those key poses. Or we could run a simulation, then feed that back to anim, where they could do some high-level curves and animation keys on top of that.
It was all about hitting comic hero beats. It’s all about what the picture was in those particular moments with the cape. Sometimes we animated those moments then tried to sim in between. Sometimes we ran a sim and were like, ‘Oh I like it and it feels very natural, but can it do this at this one moment?’ We went the other way and just had anim put little tweaks on top of that. It’s basically simulated, but we could fudge it a little without having to try to just sim it over and over and over to get magic.
One shot with Batman got so complicated that at one point we said, ‘Do you want us to just make it digital?’ They were like, ‘Yes.’ That meant Andy had the creative freedom to direct the characters instead of having to try to stitch the plates together.
Simeon Duncombe: Yes, your hands are tied sometimes if you have to lock into plates. I remember the point where we got really good at digi-doubles several years ago, where it was no longer an argument. It used to be a hard sell, because animation would always be the first to pitch digi-doubles in order to free up the camera and action, whereas compositing downstream would be, ‘Hand me the plate!’
Kevin Smith: We had some incredibly huge closeups on Supergirl that are CG, and I just don’t think people realize. One is her flying to camera and it swings around the side and pushes into her ear when she hears the battle. That’s all digital. Five years ago that would’ve been a nightmare. Now it’s like, well, we just have to put a little more work into it.