'Avengers: Endgame' Final Battle Secrets Revealed: How The Biggest Shots Came Together, Captain Marvel, Cap Wielding Mjolnir, And More [Interview]

The final confrontation in Avengers: Endgame is one of the most epic scenes in comic book movie history. It's as if a comic splash page came to life, grabbed a basketball, and windmill dunked on the airport fight in Captain America: Civil War. The Endgame battle is a fight between good and evil on a truly tremendous scale, full of the type of jaw-dropping, "holy shit" moments that make you wonder how any other film in the Marvel Cinematic Universe will ever be able to top it.

We'll have to wait and see if that ever happens, but in the meantime, I spoke with Weta Digital's visual effects supervisor Matt Aitken about how Endgame's final battle came together. Weta created the VFX for that sequence, and Aitken told me about how much the battle changed over time, which actors were present for its key moments, that applause-inducing moment when Captain America grabs Thor's hammer, the nanotechnology in Iron Man's suit, and much more.

How much did that final battle change from the conception to the final version?

It was constantly evolving. I think that's the thing with these films: the filmmakers are constantly honing the story until the very last moment. They'll use every moment that's available to them, and we support them in that by making sure that we allow them to keep their creative process open as long as possible. Which can lead to us finishing very close to the film – I think it was within two weeks of the premiere that we wrapped on this one, which is about as close as they can get, really. But we love engaging with the filmmakers to work with them in that way.

It's interesting, with this one, the environment underwent a big change after the plates for the battle were filmed. So the end battle was largely filmed in a block of additional photography which ran from September to October [of 2018] in Pinewood Studios in Atlanta, Georgia, and they were shooting on multiple stages with multiple units running at the same time. We have the Avengers compound, which is on the banks of the Hudson River in upstate New York with woods around it. So the environment would be a combination of destroyed built environment, with certainly dirt, a lot of rubble and building elements, but also some busted trees and tree stumps and burnt out trees. But when it was all cut together and assembled in a rough cut with pre-vis, those tree stumps that they'd dressed the sets with became a bit more prevalent than they had anticipated and wanted the scene to look like. Because it sort of read more like they were fighting in the ruins of a bombed out forest rather than the ruins of a bombed out Avengers compound. So for a majority of the sequences, we actually ended up roto-ing the characters off the environment and replacing the environment with a fully CG bombed out crater.

But that's all right, because we get control of the art direction, if you like, of the crater. That way, we can take more of a creative lead on the way the lighting in the environment plays out. So we're subtly modulating the lighting all the way through the fight, and that's in response to how you can kind of tell the sway of the battle is moving from side to side. So initially, once Thanos has used his ship to destroy the compound, it's really dark. When our three heroes, almost out of desperation take on Thanos, that fight is very dark, clouded over environment. Then the portals open and all our heroes turn up, and we allowed things to get lighter at that stage, so there's sort of an optimism that's allowed to play through the scene. Then Thanos gets his army involved, and as the fight progresses, it looks more and more like he's going to win, like he's going to dominate. He uses the ship to strafe the whole battlefield, and indiscriminately destroy his fighters as much as our heroes' armies. So things get dark again at that point. And at the end of the sequence, when we have post-snap Tony, with that scene tragically playing out as it does, we allowed a kind of dawn light to break. Even though it's an end, it's sort of playing like a new beginning as well.

How many actors are in most of the given shots, and how many are composited from multiple sources?

There's a few shots where, and this is really just a logistic thing, the actors who were needed to be in these shots just weren't able to be on set at the same time. That's the logistics of dealing with a really big, complex, world-class cast. These people have multiple projects on the go. The "women of Marvel" beat, when those women all come together and support Captain Marvel, there's one shot at the start of that where people just keep coming into frame. It's beautifully choreographed, the way it reveals. They were all there on that day, which is an amazing day to be on set for sure, in terms of the power of the acting presence.

Who wasn't there on that day was actually Tom Holland, playing Peter Parker. He wasn't able to be there on that day, and Peter Parker needs to hand the gauntlet to Captain Marvel at the start of that shot. So there was a stand-in on set on the day for that, and we picked up our Tom Holland element later on.

What about that shot that ends with Cap saying, "Avengers...assemble," where you're going down the line and you have everyone with all of the portals? There are so many people in that shot, I imagine that had to be pieced together.

No, they're actually all there.

Really?

They're all there, yeah. Iron Man, he was there on the day, but he wasn't going to be in that shot originally. He was supposed to be pulling himself together on the battlefield from where Thanos had left him, so we actually added him in. And The Hulk is added in, obviously. But no, I think there's actually been footage that's started to leak online that the cast filmed of each other on that day. That was the day when everybody was there. It was an incredible day.

There's another example, though, which is actually the portal shot of Titan. We really just see Titan really clearly in one of the portal shots, but it's a key shot because we have Drax and Mantis and Strange and we see Quill turn up, and everybody's waiting to see Spidey, because everybody was devastated by Spidey's blip at the end of Infinity War. I anticipated how this was going to play out, and the couple of times I've seen the film with a live audience, it's actually completely played like this. You know people are recognizing Titan, they see Strange and Drax and Mantis, and they think, 'Ah, this is potentially where Spidey's going to come.' And they see Quill, and they go, 'Oh my God, there's only one person missing from Titan now,' and you see him start to web in in the background, and the crowd just goes crazy at that point. It's just amazing. The payoff is huge.

But getting everybody together for that one was tricky. We had Drax and Mantis together, we got the two of them. Strange was necessarily on a different plate because he's floating, so he shot separately on a green screen. Chris Pratt wasn't available on that day, so we picked him up later on with a separate motion control green screen element. And Tom Holland for Spidey had to be another day again, so there's actually four different plates for that one shot. We're doing like a faux motion control on the day. Using real motion control will just grind a production to a halt. It's so cumbersome and unwieldy. So we're being a little more light on our feet than that, but it does mean we've quite a lot of tracking and restabilizing and lighting that we have to do in post to make all of that work, but it worked fine.

You mentioned the portals – how many different locations did you have to create for the interiors of those portals?

I actually haven't done a count, but I can list them for you. So there's Wakanda, for sure. New Asgard, which is where Thor and Valkyrie have ended up, in Norway somewhere. Then we've got Kamar-Taj, the sorcerers are all coming from Kamar-Taj. We've got Contraxia, which is where the Ravagers come from. We've actually got Ravagers coming through on sky cycles from more like a deep space environment. So we just had one of those classic MCU, gloriously colorful sky and star fields that our matte painting team worked up. And then we've got Titan as well in a few shots. So...however many that is. (laughs) Six or seven, I suppose.

Tell me about Captain Marvel. Are there any particular joys or challenges to her moments in that fight?

She's got her binary mode effect, which had been developed for her own movie, so we had that to reference.

Even though Brie Larson shot this movie before Captain Marvel, but you guys were able to do post-production on this after Captain Marvel came out?

Yeah, we did the whole thing quite late, so it actually works in that sense that we were able to get reference initially while they were still in progress on the Captain Marvel movie. We got work in progress versions of her effects sent through to us, and then as that show came together, we got the final versions of those shots to make sure we were on target with that. That's quite a complicated effect, so we had to make sure that was all working. She had a great costume that they'd worked out for her, which was like her 2024-era Captain Marvel costume. But in post, the filmmakers decided that it could look even better, so they redesigned it, and we ended up doing a CG costume for her throughout as well. But in general, that stuff went pretty smoothly. It's a lot of work, but we were very mindful of the fact that she is a key character now in the MCU and we had to do her justice.

Tell me about the "Cap wielding Thor's hammer" moment. That's the biggest audience applause break in the movie from the times that I've seen it.

Yeah. The fans, it's almost like they were anticipating that moment. We hoped that that was going to play as well as it does, because we're a bunch of fans as well. (Pauses) Which film is it where he tries...?

Age of Ultron, where he moves it a little.

Yeah, that's right. There's almost like a sense that he's going to be able to lift it at that time. So the groundwork was laid back then. No, those were just great shots to do. They weren't particularly challenging. We had the lightning that we had to work up. We wanted that to look really good. We just knew that was going to be a thing. When you see Mjolnir lifting up off the ground slowly, you know it's not Thor, because he's being dealt to by Thanos. It's as much a surprise to him as it is to everybody else. But that shot where we whip-pan with the hammer and see Cap holding it, the crowd goes crazy at that point. We did three versions of that shot. The one that ended up in the film, there's no lightning on Mjolnir, but we did a little bit of lightning and then a bit more lightning as well, and we presented them to the filmmakers and they were editorially able to play around with which one they went with.

That's cool. So Thanos's army, we see the Chitauri, we see the Outriders, I think there were some other forces that we hadn't really seen before. Can you tell me about them, and if they had any names that the Russo brothers or the screenwriters gave to you guys?

Yeah, so there's the Sakaarans, and I think we see them first in Guardians 1, on Morag. They're kind of the ground troops who were trying to stop Quill when he grabs the Power Stone and escapes from Morag. So they're there. We've got the Outriders. The majority of the Outriders this time have actually got two legs and six arms, so they're actually eight-limbed creatures. There were a few of those in the Battle of Wakanda in Infinity War in the ILM sequences there, but in terms of upping the ante, most of them were the eight-limbed variety for Endgame. There's the Chitauri and their chariots, of course, from the Battle of New York from The Avengers. At one point, there were going to be – potentially dark elves were going to show up, they didn't make an appearance.

But the guys who are new are particularly the Chitauri gorillas. We see the Chitauri leading them out by chains and then they set them free. These are not quite King Kong sized, but yeah, giant gorilla-ish, alien gorilla creatures who are a formidable force to be reckoned with on the battlefield. We got 2D concept art for those guys, worked them up in CG – we've done one or two gorilla creatures in the past, so we've got a little bit of experience there – and they were great fun to do. Great fun to fight with, and then great fun to kill off.

You mentioned the dark elves. Were there any other big moments like that which you were sad to see get cut?

The dark elves were mentioned, but we never got as far as rigging them or making them for the battle. No, it continued to take shape all the way through, but of the MCU films I've worked on, it's the one that really changed the least from when I first saw a rough cut through to when it opened. It was always about three hours long, it never seemed to deviate from that. Little bits came and went early in the film, but once we had finished that additional photography block, Jeff Ford, the editor, cut that stuff into the film pretty quickly. I was able to watch a rough cut of the film in mid-September when I was still up in Atlanta, and from then on, it didn't really change that much at all.

I think I read somewhere that Korg and Miek were initially involved in that battle. Is that true?

They are there. They turn up in the portal sequence. They arrive with Valkyrie, and they're in the Avengers Assemble shot. We see glimpses of them. They're in the charge. Miek is wearing his battle armor, which includes articulable legs. He's able to run in the charge. There's a shot that we did that's really the moment when the two armies clash, which is a big, complex, multi-beat shot that sweeps through, I think there's like three different plate elements that come and go through the shot, but mainly it's fully CG, and Drax runs in and jumps on the back of Kull and is stabbing away at Kull. At the same time, Korg is smacking him in the chops. There's little glimpses of them.

I went and saw the movie last night to prepare for this and there's so much going on. I feel like I need to see it a few more times to really allow all of that stuff to sink in.

I think it withstands multiple viewings. It's very dense filmmaking. There's little gems in there that...I'm not even sure I should reveal this or not, although the internet has spotted him.

Howard the Duck?

Howard the Duck. Yeah.

I was going to ask about that, if there was anybody else like that that we should be keeping our eyes out for.

It was great, because I personally have a soft spot for Howard, irascible as he is. He was actually mentioned in the very first draft of a screenplay that I ever got to read for Endgame, which did change a lot. That was 2016 I think, was when I first got to read a very rough early draft. He was mentioned in the end battle in that early draft, so I was like, 'Yeah, yeah, Howard the Duck's going to be in the end battle!' If Howard the Duck is in there, that means everybody's going to be in there, right?

He ended up not featuring in the end battle, but very late in the day – and I think it might have come from Kevin Feige, actually – we got the note that if there was a chance to get Howard the Duck in. There was this one little gap when the Ravagers were coming out of Contraxia where there was room to drop him in, and he wouldn't be too obvious, which is good. It was the way they wanted to play it. It would involve us essentially building and rigging and shading and prepping a hero digital character for one tiny little beat. I've counted, he's actually in eighteen frames of the film. So it's not like a huge presence. That's a lot of work for a small amount of time. But we were so delighted to be able to do that, and what we heard that when we sent the shot through and it was reviewed in the screening room at Marvel with the filmmakers, they were all clapping and cheering to see Howard.

Did you have access to – or does it not really work like this – the character designs and models of Howard's first appearance in the MCU? Were you able to use that to inform what you did, or did you have to redesign it from the ground up? How did that work?

Yeah, it's a really good question. Not just with Howard, but a whole bunch of these characters and creatures, they've made appearances in other MCU films. So Marvel are great. They will always make sure we get delivered those assets from other vendors. The last thing we do on any of these shows is package everything up and send it back to Marvel so they've got it for future reference and future use like this. There's always work we have to do when we pull a character from another facility, because so much of the way we all individually approach this work is proprietary within our own facilities, so we all need to use what we can but then build out the rest in our own individual pipelines. Sometimes the assets will work the way we get them in terms of level of detail. Sometimes we'll want to do a pass because our requirements may be more higher scrutiny than the level that they were built for on the other shows. So we might need to do some up res-ing work as well. But there's a lot of that kind of swapping around of assets that happens.

I know you also worked on the nanotechnology aspects of Iron Man's and Spider-Man's suits. What can you tell me about that?

Yeah, that's some tech we developed on Infinity War first. So we used a helmet reveal to re-develop that tech, that's something we're doing in Houdini, which is a simulation package that we use. It's a combination of particle simulations and fluid simulations, so the material kind of moves around like a fluid metal, like mercury or something. The gag is that it sort of locks in like an underlying grid structure, so it kind of crystalizes and forms a grid, and we're doing that with procedural modeling techniques in Houdini. The outer shell of the suit will sort of swell out through that and lock into place. We had a lot of fun on Infinity War with all the different weapons that Iron Man generates using this tech, and we get to contribute to the design of those and the build of those.

It's really only used in a few key moments in Endgame. As part of the initial battle, Iron Man generates what we call the lightning re-focuser and catches Thor's power and turns that into a really high-powered blast of his repulser energy to Thanos. The main use of it really was the snap, when Tony uses that tech to form a gauntlet on the fly. He's palmed the stones off Thanos without Thanos even realizing, and he's used his nanotech to move the stones into place on the gauntlet. And then obviously the Infinity Stones, there's all this power that starts to generate and surge through the suit, and we had the suit kind of trying to protect Tony from all this power and energy, so there's quite a complicated bleeding edge effect that's playing through those shots. As we worked on reviewing those shots with Dan Deleeuw, Marvel's visual effects supervisor, and the filmmakers, we really worked on finding the balance between showing all that power and all of that destructive energy and the damage it was causing to the suit, but not having it be so distracting and flamboyant that it took away from Tony's moment. This is a key Tony moment. So that was a real balancing act that we had to work through there.

Earlier in the film, you see Tony going to great care to design a specific gauntlet. Were there ever any conversations about how this was actually possible that he was able to generate one on the fly? Any story reasons you heard about?

I think it was really that he was never going to be the one to wear it, initially. You see the stones being carefully calibrated into place. That was when they were being cautious, and ultimately it's Hulk who ends up wearing it. This is shots that ILM did, so I'm only just talking as an audience member here. The gauntlet that he makes there is going to fit itself to whoever's going to wear it. But in the heat of the battle, and he realizes that this is the one in 14,000,605 that Strange has been talking about, this is the way it's gotta go, in this moment of ultimate sacrifice, he really throws caution to the wind. He's more cavalier and he just builds a gauntlet on the fly. There's no real protection going on there, but he knows it's gone beyond that anyway.

And finally, what is the aspect of the work that you and your team did that you're the most proud of?

For me, both times I've seen the film with an audience, the way the portal sequence plays out is immensely satisfying. The way it was written and conceived by the filmmakers, I knew it had the potential to be an amazing sequence within the film. People say it's the most emotional moment of the whole film for a lot of people, I think. And I didn't want bad visual effects to detract from that. So we put a lot of effort into making that stuff work really, really well. All those environments are full 3D CG environments so that they track with the moving cameras incredibly accurately. We wanted it to look beautiful as well, you know? This is a glorious moment. We've got these giant portals, there's sparks drifting around, there's nice color complexity in the shots. So yeah, I definitely didn't want to make a mess of it, and I think it worked out OK, and it's had a fantastic reaction from the audience both times I've seen it, so it's been wonderful.