Not even the most reluctant animal-lover can watch Okja without feeling an emotional attachment to the creature at the heart of the movie. Bong Joon-Ho's Netflix film has much the same effect as Babe; even though Okja is a genetically-modified super-pig raised in order to end up on a meat farm, you can't help but come to see Okja as a beloved sentient being that deserves a chance to live its life. 

This is in large part owing to the blood, sweat, and tears of Okja's VFX team, which accomplished the stunning feat of bringing a 100% CGI creature to life across a complex production. At the head of that team was Erik-Jan de Boer, who won an Oscar in 2013 for his work on Life of Pi. On set, de Boer created many different puppeteered versions of the animal according to what the scene required. He mapped out the puppet rig's every move to child actress Ahn Seo-hyun, who plays Mija, Okja's owner, so that she could sustain a believable performance in the absence of her co-star. He instructed cinematographer Darius Khondji on where and how Okja would move in the frame. Then, back at Deluxe Studios in Vancouver, de Boer and his team animated the super-pig with a breathtaking attention to detail.

Producer Jeremy Kleiner summed it up: "The ability to create a fully CG character in a live-action film that is as real as the human beings, and where the emotional reality is as real as in the most naturalistic of films—it’s an astonishing feat. There is a level of seamlessness in the interaction between Okja and the characters around her that is astounding—and it all stems from the amazing interdepartmental partnerships between these teams, all of them going to great lengths to give us a living, breathing Okja."

No Film School caught up with de Boer to discuss getting creative with the process, including using a pogo stick to simulate riding the super-pig on set, and how he pushed technology to its limits in order to create the complex workflow that gave birth to the Okja we know and love.

No Film School: What was the process of getting on board Okja?

de Boer:Stan Glass, who is the tech supervisor at Method Studios, had worked with Bong [Joon-Ho] in the past. I met with Bong for the first time and he showed me the object concept. He didn't have a script ready to share yet. He was interested in working with me because I had done a lot of movies with kids and CGI animals. We discussed how we would go about approaching something like this. And then, of course, it took a year and a half or so before we started shooting it. 

NFS: And what happened in between that initial meeting and the first day of production?

de Boer: Once we did a full breakdown of the script, we started to identify all the shots that would require some very specific physicality and interaction with the creature. We built this full range of "stuffies," as we called them. They were basically foam props that allowed us to solve all of these visual challenges that we had ahead of us. Some were just specific to one shot, but others were more generic and we could repeat use them.

"For when Mija is riding Okja, we built a huge pogo stick so that it has all the physicality that you would expect when you ride a big animal."

So we had, for instance, a head that was very light, so we could run around and puppeteer with it easily. But we also had a version that was a lot heavier, so that we could properly bump and exert some serious force with it. We could Velcro the ears onto it, or take them off depending on the challenges of the shot.

We also had a neck piece, a bust, a flank, and a whole range of props and tools that we could use to solve each of these setups. One of the things that we always did was bring out a PVC rig that reflected objects' sides properly. That allowed us to very effectively show the camera operator how big this animal was and what the final choreography was going be on the screen. So we would rehearse, lay out the choreography, and then switch to a more detailed prop for the final shooting.

1200_9'Okja'Credit: Netflix

NFS: So the detailed prop was what Mija [the main character] was interacting with on set most of the time.

de Boer: Exactly, yes. And those were made out of EPA foam that we cut out of flat sheets of foam and then glued together into the shape of objects. They were based on 3D models that we supplied to this company called Cell in Korea, and they printed them out the then glued them into the final shapes.

For when Mija is riding Okja, we built a huge pogo stick so that it has all the physicality and the momentum and the percussiveness that you would expect when you ride a big animal like that. Traditionally, that's done with a hydraulic motion-based solution, but we did it with a big pogo stick so that we had the proper hang time and all the overlap in the clothing and in the hair that you would expect from riding a creature.

We would rehearse each scene with Mija so that she felt very comfortable being on top of these props and riding them. We wanted her to focus on her performance—it was very important to us that she always stayed in character and understood what we were doing. So if she had to ride on top of this pogo stick, or crawl out of the mouth when she does the toothbrushing, we always rehearsed that with her, so that she was comfortable and that we didn't have to spend time on set going through that stuff.

"We used a lot of dog references, especially Labradors and Vizlas, to animate the facial performance."

Some of these shots were actually pretty tricky choreography, with switching some of these props around so that she would be touching the neck in one moment and then pushing the butt at the other. And then we would swap them during the take so that we would always hit the right moments. When you look at the original footage, it doesn't make a lot of sense. But then when you see Okja go through her paces, then it sort of all falls into place.

There was a lot of stuff happening on location. Some of the locations were very hard to reach and we had to fly some of these props in with a helicopter. But it was very cool. My animation director, Stephen Clee, who also did all the post-production work on the creature, would run his team of animators during post-production, which was 25 people. But he was on set with me at all times, and he always puppeteered these props. So he was in front of the camera with Mika, acting out Okja's actions. I was with Bong behind the camera, looking at the monitor, and connected through a radio with Steve, so he could make adjustments and timing changes between takes.

Having a system like that really allowed me to get the right motion and physicality out of these props. And because Steve is an animator and he knew what we trying to achieve, he could execute properly and deliver a proper object performance on set. But then he took all that knowledge back home to Vancouver, and then directed the team to animate a CGI object to the level that you see in the movie.

Okja-ff2-006'Okja'Credit: Netflix

NFS: That's an incredibly intricate process.

de Boer: Yeah. Bong and I had discussed this from the start. And I explained it to Bong: The only way that people are really going to believe Mija and Okja and their little pet friendship is if we have a lot of contact, and if that contact is truly believable. And the movie has a lot of really intricate and tender caressing and stroking. Some of that stuff is really hard to do in CGI, and it took a lot of hard work from all departments in post-production to pull that off.

So you have all the physical moving, then you have the animation, then the lighting, and then, of course, the compositing. And if you think about the quality of the contact shadows and all that needs to be in the animation—to make sure that the live action and the CGI are properly married together and that you can really feel that connection—that is really tricky work. And the team really did a great job.

NFS: Were you responsible for bringing Okja to life in terms of her personality, face, and the way she moves—sort of like a playful hippo?

de Boer: Yeah. As part of our character studies and the development of the creature, we do a lot of R&D to get the right musculature and skin definition into the creature. That is a very technical and complicated process.

"It's very easy to over-animate or to go too cartoony on this. You really have to restrain yourself."

Since Okja was designed as a GMO, she had to come across as a believable meat producer. So it was very important for us and for Bong that she had a very healthy and luxurious feel to her skin and her mast. You could harvest a lot of pork from her.

But another part of it, of course, was that she needed to be appealing and that you could enjoy looking at her and Mija together. She had to have a certain pleasantness to her. So we did a lot of facial performance studies. It's very easy to over-animate or to go too cartoony on this. You really have to restrain yourself and dial it in to the right level. So we used a lot of reference from nature: hippos and elephants for locomotion, for weight, and for any sort of skin or muscle reference. And we used a lot of dog references, especially Labradors and Vizlas, to animate the facial performance.

Okja_0Original sketches of Okja alongside the animal prototype.Credit: Netflix

NFS: I'm a huge dog lover and I found myself feeling an emotional connection with Okja the way that I would if I were interacting with a dog. So it's interesting that it has a basis in the mechanics of how you built the animal.

de Boer:Right. Yes. And there is a certain sentient feeling to Okja because, of course, she rescues Mija from the cliff. And that definitely goes beyond what your Labrador would be able to figure out. So there is a little bit of enhanced intelligence there, but I always asked the animators to play her as if... I mean, she's listening, right? She's trying to pick up a few key words that she knows.

NFS: What was the most complex shot to orchestrate from start to finish? I know every single one must have been. 

de Boer:Yeah, you're absolutely right; there were a lot of those! From a CGI point of view, there are some shots where she's swimming in the water, and all that water is CGI. So that's always very challenging to do, from a technical point of view. In terms of stuff that involved a lot of mechanical bits and pieces, the tooth-brushing was difficult, and Mija sleeping on top of the animal was a really tricky one. 

"From a technology point of view, we're always trying to push ourselves further and try to do better."

But one of the most exciting shots was the shot where she runs up to Okja and then flips onto her neck and starts riding her out of the traffic tunnel. First of all, just the process of shooting that and getting the camera to do the right thing, getting all the extras to look into the right spot at the right time, putting all those cars in the right places, doing all that with the constraint of the location and availability of the tunnel...that was really very exciting. But what was really cool for us is that actually involved a full digital media. So Mija, in the first half of that shot, is a digi-double. She's actually virtual. And then at the end of the shot, when she comes around the corner, it's actually a green screen element that we shot on the huge pogo stick. We had CG cars that are being banged and pushed around, we had live-action cars, we had live-action people, we had a digi-double, we had a live-action Mija, and then, of course, Okja running through that whole thing. That shot was really an interesting puzzle to do.

But if you look at the underground shopping mall, for instance, we actually built the part where Okja crashes and slides into the store. That was actually built on a stage. We drove a real minivan into the store to get the proper chaos and collision that we needed from that moment. And that was really exciting.

Okja-ff2-008'Okja'Credit: Netflix

NFS: Was there anything that you had to teach yourself on this project, or that you had to conceive especially for this project that you hadn't done previously?

de Boer:Yes. Almost everything is new. Just the simple fact that your team is always undergoing change and you have new players on your team that you have to deal with...that is always a challenge.

But from a technology point of view, we're always trying to push ourselves further and try to do better. One thing that I think I was more conscious of this time around was just trying help Mija deliver the strongest performance while she was dealing with the props. I realized that that really is also the responsibility of the VFX team. It's not good enough for us to just hold up a tennis ball and say, "This is where the creature is." I really tried to help Mija as much as possible to understand what Okja was doing and feeling, and to connect with that piece of foam on those props. I think that really paid off at the end. 

NFS: Do you have any advice for up-and-coming VFX artists?

de Boer: It sounds sort of cliché, but just keep your eyes open and look at how people move, how life behaves. Keep drawing, and really just try to get your head around a computer and make sure you're comfortable with all the functionality and the tools that are available to create images.

Make sure that you enjoy how light plays off the water and how reflections and refractions work. And how shadows look.