This past weekend, Marvel’s Thor: Ragnarok became the studio’s 17th straight number-one opening, thanks to a well-established formula of heroic action moments, grand mythology, and evil entities eager to destroy the universe. The format fits the familiar pattern of the Marvel Cinematic Universe, but Ragnarok nevertheless stands out due to the unique comic sensibilities of director Taika Waititi. He doesn’t take himself — or superheroes — too seriously, and he heavily incorporates the kind of improvisational, character-based approach that he honed with indie movies like Hunt for the Wilderpeople and the improv vampire comedy What We Do in the Shadows. The resulting movie is hilarious, irreverent, and totally unique.

But Ragnarok is also a tentpole visual effects film, filled with CG characters like Hulk, artificial environments like the planet of Sakaar, and massive superhero fights. Talking to visual effects supervisor Jake Morrison (The Avengers, Ant-Man), it’s clear that the combination of elements presented an unusual challenge: Morrison needed to devise a visual effects strategy that would let Waititi shoot the film and work with the actors using the methods he’d grown accustomed to, while still delivering on the blockbuster spectacle any Marvel title requires. Before the film’s opening, I jumped on the phone with him to discuss how he and his team turned the Hulk into an improvisational actor, the secrets of Cate Blanchett’s shape-shifting costume, and why a children’s stunt double ended up fighting as Thor.

Taika Waititi brought a unique sensibility to this film, but he’d never tackled these kind of visual effects before. What was his approach when you first met, and how did you help him with the process?

There were really two things that we touched on, and the first one was the most freeing thing for me. He said, "I like the way I shoot my films. I shoot long takes.” He doesn’t cut camera very much; he just keeps rolling. He likes to be behind the camera. He's throwing lines out at his actors, keeping them off-balance, coming up with fun new things on the go. Anything that comes to mind, with the view that a lot of the stuff you shoot may not end up in the picture, but it's nice to try.

So he wanted to be able to make sure none of the technology got in the way. I could see his concern that if you've got a scene where Mark Ruffalo is riffing with Chris Hemsworth, Taika wanted all the Hulk / Thor banter to be completely improv — or to be able to be completely improv. We had written words [in the script], but he wanted to be able to go beyond that.

He basically said, "I don't want to have to have hundreds of people running in and doing technical adjustments with head-mounted cameras and stuff like that. I just want to shoot the actors. I trust that you know what you're doing, but make it so I don't have to think about this stuff." So that was something we took onboard really early on, just to make sure he had all the tools he would have on a normal picture. Ricky Baker and Sam Neill's characters in Wilderpeople are actually riffing, like they're talking to each other, and it should be as transparent as that to Taika when he's got Ruffalo and Hemsworth, and they're having at it. Like the scene where [Hulk and Thor] are kicking stuff from left to right across the room, or the make-up scene on the bed. That's all improv, and that's Taika throwing out all these lines. So the thinking was the same way.

What techniques did you have to incorporate on-set to make shooting feel organic?

We came up with some really interesting virtual production techniques. When the camera operator put their eye to the eyepiece of the camera, they would actually have a live version of the Hulk overlaid on top of Mark Ruffalo. So if you had a shot where you're panning from, say, Chris to Hulk, you actually want to pan from Chris to Hulk, not Chris to Mark — because Mark is 5'10" or what have you, but Hulk is 8'6".

In the middle of all this computer-generated imagery, there really seems to be a focus on getting as much as you possibly can in-camera. It feels like the technology has evolved to such a degree that the focus can be on letting filmmakers shoot the way they want to shoot, rather than letting a visual effects technique define their process.

As it should be, really. If you go back 15 years, there was a moment where, as an audience member, you would look at a film and you'd go, "Okay, I can feel there's an effects shot coming up," because the camera would suddenly stop and lock off. Almost like Bewitched, when everyone would just freeze in place, and then somebody would run out of frame, and you'd start the camera again. It wasn't really that far from that for a long time, and I think our emphasis as visual storytellers now has been to really lean on making sure the tools are as transparent as possible.

I go to films for the people, the characters, the journey; for the humor, the drama. Everything else we do as visual effects is set dressing. It's the sprinkles on top. It's the fun stuff which helps you believe the environment the characters are in, but they should never eclipse the performance.

Something like this, like Thor: Ragnarok, is Chris' film with an incredible ensemble cast. You want to see Tessa Thompson, you want to see Tom Hiddleston, you want to see Jeff Goldblum and Cate Blanchett and all that stuff. Even though Cate Blanchett’s suit is 100 percent CG the entire time. Our job was is to make sure that if you've got an Oscar-winning actress in that role, if she does a small aside and just does a small hand gesture, that's not something we in the VFX community should be ignoring. We should be honoring that. So the entire performance, making sure it really flows straight from whatever happened on camera that moment, with the director directing, is the final thing you see — just kind of the amped-up, coolest version of the scene we can do.

You said Cate Blanchett’s entire costume is computer-generated. What was she working with on the set?

We did a hybrid. We decided early on that we wanted to give Cate a cool suit to wear. Because it's good for it to be all on-camera and in character, and sometimes the gray [mocap] leotards are not the nicest things. I've had many actors wonder why the hell we can't come up with something better, so for this one we did, and we built a custom suit for Cate which looked absolutely amazing.

We took the motion capture markers down to a size they'd never been before, and we embedded them into the suit. So if you actually see the behind-the-scenes footage, you can see that Cate is covered in these little dots, which are not quite the ping pong balls [normally used]. They're these tiny little things, like tiny hockey pucks. And then there's wires running all over, and there's two battery packs on her, and all that kind of stuff.

We did that in conjunction with the art department. With the art department, we would actually build all the motion capture cameras into the sets themselves. To Taika's point at the beginning about not letting the technology get in the way of the performance, we didn't want to have to shoot a scene with Chris and Cate, and then say to Cate, "I'm sorry, we need you to go off to Stage 4, which is a little gray mocap [stage called a] volume, where you're going to have to stand there and then re-perform the scene again." Because you won't get the same performance twice. It's all about capturing that moment.

We actually had it so all the sets had mocap cameras built into them. So if you take the throne room scenes, for example, we had mocap cameras ringing those. The Korg meets Thor scene, for example, we had Taika in the [motion capture] rig, there are actually panels built into that prison set. If we were shooting a scene with Loki and Thor, we would just put the panels in. And if we had a motion capture scene, we would then pop the panels out and you'd see the mocap cameras behind there. We just had to paint them out [in post-production]. So it meant that, again, everything was happening in situ. It made the actors more comfortable: you're really in sets, and you can really use that entire performance.

Hulk and Thor have this really fun Odd Couple chemistry, and that’s largely possible because Hulk talks more than he ever has before. On the visual effects side, what enabled you to make this new, chattier Hulk?

We started from scratch, actually. We went back to ILM, because Industrial Light & Magic have the history, and they've built every Hulk so far. But the Hulk has only really ever had to deliver one line, in Avengers 1, where I think he said, "Puny god." So it's like two words that you've ever had, over two pictures.

When [Marvel] told us, "It's an exciting picture. By the way, we're going to have Mark Ruffalo in it," that means we've got the Hulk; that's awesome. And then the moment of extreme disbelief was where they said, "Well, now the Hulk actually has to tell jokes." That's a hell of a thing to hang off an effects element. We went back to ILM and said, "We're going to have to re-engineer this from the beginning."

So we figured, “Okay, if Banner’s been trapped inside the Hulk for the last two years, they've probably morphed a bit more, and there's a pretty good reason that the Hulk should look a little bit more like Ruffalo.” Because Mark is actually delivering these lines, and you've got his facial performance and all the rest of it, it only makes sense that we should try and bring that actual physical structure of Mark's face into the Hulk.

So you see a completely different Hulk. He can do things the old Hulk couldn't do, simply in the sense that his mouth can make different shapes. He hasn't got the broadest vocabulary, but he could. So it was a rebuild from scratch, and I for one just enjoyed giving him a fresh haircut, too.

Sometimes when I’m talking to visual effects supervisors, we’ll hit upon some sort of small, almost accidental breakthrough that came up during the course of making the film. Was there anything like that on Ragnarok?

I think there's this really abstract breakthrough that started off as what could be a terrible idea, one of those ones when you're just wool-gathering like, "Well, we have to put a fight together between Hulk and Thor."

I worked on Avengers 1, where we did the fight in the Helicarrier. Chris would be battling this really big guy called Troy, who's like 6'7" or something like that, and then SFX built this extra little padded suit that went on top of him that had a Hulk-sized head, and all the rest of it. But what I took away from that one is that really, because their shoulders are about the same height, all the punches were thrown just like a bar brawl. There's nothing that made it into a super-fight, that made this stuff believable. The Hulk vs. Thor fight is a big centerpiece [of Ragnarok], and you want the audience to believe this is really these two gods actually battling it out.

I'll be honest with you, I had this idea… I was like, “Well, Chris is 6'4", and the Hulk is 8'6", but we can't get an 8'6" guy. So what if we reverse-engineer that?” And we go, "What if the Hulk was 6'4"? Can we find a stunt guy who's actually the reciprocal math?" And we did the math, and it turned out that 4'8" is the right number.

We dug into it, and we found this amazing stunt player called Paul Lowe in London, who does a lot of stunts for the Harry Potter films. He doubles for kids as a stunt player. He is built like a boxer, frankly. He's basically a scale version of Thor. So we were like, "Well, what if we do this scale mocap thing? Could it work?" And the answer is, it does.

So we choreographed the entire fight with Paul at 4'8", and Ryan Tarran at 6'4", who's one of our Thor stunt doubles. We were able to actually make it so if Thor's punching at Hulk, it’s an uppercut. If Thor kicks Hulk, it's a kick in the knee, as opposed to the belly. If Thor runs around the back, it's a kidney punch; if you jump up and do a stranglehold, it's actually a leap to get up. And all of this enabled us to actually create a fight which really worked viscerally, and you actually feel that these guys are really in there and wrestling correctly.

So we motion-captured that entire fight in our mocap volume, then taught Chris [Hemsworth] the Paul version, the scale-Thor version of the fight. He performed that on a blue-screen stage just against heavy bags and focus mitts, and stuff like that. Then, when we took the Hulk mocap from the fight and plugged that into the Hulk model that ILM had, and put Chris' blue screen together, those two things locked in. And then after that, the ILM animators run wild. But it meant that the bones of the fight, the grounding of the whole thing, feels much more real, and much more visceral, because it really is the right scale.

That's such a great low-fi hack.

Yeah, it's literally one of those moments where you're like, "Is this the stupidest idea anybody's ever come up with?" And then I suggested it, and everybody's like, "I guess I can't see any reasons why it wouldn't work." And then we just did it.

Thor: Ragnarok is now playing in theaters.