By Iain Blair

The Fox family film The Call of the Wild, based on the Jack London tale, tells the story of  a big-hearted dog named Buck whose is stolen from his California home and transported to the Canadian Yukon during the Gold Rush. Director Chris Sanders called on the latest visual effects and animation technology to bring the animals in the film to life. The film stars Harrison Ford and is based on a screenplay by Michael Green.

Sanders’ crew included two-time Oscar–winning cinematographer Janusz Kaminski; production designer Stefan Dechant; editors William Hoy, ACE, and David Heinz; composer John Powell; and visual effects supervisor Erik Nash.

I spoke with Sanders — who has helmed the animated films Lilo & Stitch, The Croods and How to Train Your Dragon — about making the film, which features a ton of visual effects.

You’ve had a very successful career in animation but wasn’t this a very ambitious project to take on for your live-action debut?
It was. It’s a big story, but I felt comfortable because it has such a huge animated element, and I felt I could bring a lot to the party. I also felt up to the task of learning — and having such an amazing crew made all of that as easy as it could possibly be.

Chris Sanders on set.

What sort of film did you set out to make?
As true a version as we could tell in a family-friendly way. No one’s ever tried to do the whole story. This is the first time. Before, people just focused on the last 30 pages of the novel and focused on the relationship between Buck and John Thornton, played by Harrison. And that makes perfect sense, but what you miss is the whole origin story of how they end up together — how Buck has to learn to become a sled dog, how he meets the wolves and joins their world. I loved all that, and also all the animation needed to bring it all alive.

How early on did you start integrating post and all the visual effects?
Right away, and we began with previs.

Your animation background must have helped with all the previs needed on this. Did you do a lot of previs, and what was the most demanding sequence?
We did a ton. In animation it’s called layout, a rough version, and on this we didn’t arrive on set without having explored the sequence many times in previs. It helped us place the cameras and block it all, and we also improvised and invented on set. But previs was a huge help with any heavy VFX element, like when Thornton’s going down river. We had real canoes in a river in Canada with inertial measurement devices and inertial recorders, and that was the most extensive recording we had to do. Later in post, we had to replace the stuntman in the canoe with Thornton and Buck in an identical canoe with identical movements. That was so intensive.

How was it working with Harrison Ford?
The devotion to his craft and professionalism… he really made me understand what “preparing for a role” really means, and he really focused on Thornton’s back story. The scene where he writes the letter to his wife? Harrison dictated all of that to me and I just wrote it down on top of the script. He invented all that. He did that quite a few times. He made the whole experience exciting and easy.

The film has a sort of retro look. Talk about working with DP Janusz Kaminski.
We talked about the look a lot, and we both wanted to evoke those old Disney films we saw as kids —something very rich with a magical storybook feel to it. We storyboarded a lot of the film, and I used all the skills I’d learned in animation. I’d see sequences a certain way, draw it out, and sometimes we’d keep them and cut them into editorial, which is exactly what you do in animation.

How tough was the shoot? It must have been quite a change of pace for you.
You’re right. It was about 50 days, and it was extremely arduous. It’s the hardest thing I’ve ever done physically, and I was not fully prepared for how exhausted you get — and there’s no time to rest. I’d be driving to set by 4:30am every day, and we’d be shooting by 6am. And we weren’t even in the Yukon — we shot here in California, a mixture of locations doubling for the Yukon and stage work.

Where did you post?
All on the Fox lot, and MPC Montreal did all the VFX. We cut it in relatively small offices. I’m so used to post, as all animation is basically post. I wish it was faster, but you can’t rush it.

You had two editors — William Hoy and David Heinz. How did that work?
We sent them dailies and they divided up the work since we had so much material. Having two great voices is great, as long as everyone’s making the same movie.

What were the big editing challenges?
The creative process in editorial is very different from animation, and I was floored by how malleable this thing was. I wasn’t prepared for that. You could change a scene completely in editorial, and I was blown away at what they could accomplish. It took a long time because we came back with over three hours of material in the first assembly, and we had to crush that down to 90 minutes. So we had to lose a huge amount, and what we kept had to be really condensed, and the narrative would shift a lot. We’d take comedic bits and make them more serious and vice versa.

Visual effects play a key role. Can you talk about working on them with VFX supervisor Erik Nash.
I love working with VFX, and they were huge in this. I believe there are less than 30 shots in the whole film that don’t have some VFX. And apart from creating Buck and most of the other dogs and animals, we had some very complex visual effects scenes, like the avalanche and the sledding sequence.

L-R: Director Chris Sanders and writer Iain Blair

We had VFX people on set at all times. Erik was always there supervising the reference. He’d also advise us on camera angles now and then, and we’d work very closely with him all the time. The cameras were hooked up to send data to our recording units so that we always knew what lens was on what camera at what focal length and aperture, so later the VFX team knew exactly how to lens the scenes with all the set extensions and how to light them.

The music and sound also play a key role, especially for Buck, right?
Yes, because music becomes Buck’s voice. The dogs don’t talk like they do in Lion King, so it was critical. John Powell wrote a beautiful score that we recorded on the Newman Stage at Fox, and then we mixed at 5 Cat Studios.

Where did you do the DI, and how important is it to you?
We did it at Technicolor with colorist Mike Hatzer, and I’m pretty involved. Janusz did the first pass and set the table, and then we fine-tuned it, and I’m very happy with the rich look we got.

Do you want to direct another live-action film?
Yes. I’m much more comfortable with the idea now that I know what goes into it. It’s a challenge, but a welcome one.

What’s next?
I’m looking at all sorts of projects, and I love the idea of doing another hybrid like this.

Industry insider Iain Blair has been interviewing the biggest directors in Hollywood and around the world for years. He is a regular contributor to Variety and has written for such outlets as Reuters, The Chicago Tribune, The Los Angeles Times and the Boston Globe.