Oscar-nominated VFX supervisor discusses the challenges of creating two believable CG action heroes.
As an action-packed science fiction adventure, Marvel’s Guardians of the Galaxy was the studio’s first cinematic foray outside the hugely successful Iron Man / Thor / Captain America / Avengers narrative universe. Audiences were introduced to five brand new characters, a dysfunctional group blasting across the galaxy alongside a seemingly dim-witted human, Peter Quill, played with suitably dim-witted charm by Chris Pratt.
As expected, the five rabble-rousing misfits manage to stop fighting each other long enough to band together and save the day. But what wasn’t expected was that central to the very heart of the Guardians eventual redemptive heroism was an unlikely team of two completely CG characters – a belligerent and irascible raccoon, Rocket, and a gangly, oversized tree stump, Groot.
Leading the film’s Oscar-nominated visual effects work was Stephane Ceretti, known for his fantastic work on Thor: The Dark World, Cloud Atlas and Captain America: The First Avenger, who spoke about the challenges he and his teams faced delivering a believable and emotionally satisfying performance from two completely digital actors.
Dan Sarto: On this film, a science fiction adventure complete with strange new worlds, a host of space ships and large scale interplanetary battles as well as two completely digital characters, the amount of vfx work you supervised must have been immense.
Stephane Ceretti: Ninety-five percent of this film contains visual effects, so I was involved in many, many areas of the production. As a sci-fi movie, you have many universes to create. But our main focus was creating Rocket and Groot, the completely digital characters that become two of the Guardians. It was our biggest focus certainly as far as getting the storytelling right. Framestore created Rocket and MPC created Groot. We all shared assets so both companies could have both characters in their shots. We spent a lot of time making sure both these characters worked well with the rest of the Guardians and other actors in the movie, making sure their performances were good and that audience wouldn’t question them as just CG characters.
DS: Describe your involvement with the visual development of these two characters.
SC: When I joined the movie, Marvel had already done some design work. Marvel has a design team that creates all the characters and costumes they will use. So starting with those designs, we worked with Framestore and MPC, looking at live raccoons and trees, trying to bring the designs back into real life as much as possible. There were also had some tweaks we wanted to do to their faces, especially their eyes, to get the best possible performances. So we worked on the size and shape of Rocket’s face, eyes and mask, Groot’s face as well as eyes, in addition to things like finding the right proportions between the size of the two characters, the proportions of their bodies, how they walked, all the walk cycles. We even brought a live raccoon into our office so we could study how it actually behaves.
My work really was about facilitating the progression from concept to what ended up in the movie, to discuss what James [Gunn, the director] was looking for as well as come up with ideas and solutions for capturing all the emotions and performance from the characters. We needed to ensure we got the right look of the fur, the costumes, movement, body proportions, all these types of things.
DS: What was the main challenge integrating digital characters into the live action? Did you use any performance-capture?
SC: We didn’t use any performance-capture for Rocket or Groot on the film. What we did on-set for Rocket was use Sean Gunn, James’ brother, who is a very good actor, to interact with the other actors. We tried to make it as simple and not bogged down with technology as possible, so we could get a good acting flow between Chris [Pratt], Zoe [Zaldana], Dave [Bautista] and our CG characters. We used two guys. We had a mime for Groot on-set as well as Sean for Rocket. We tried to keep it very light in terms of technology, so we could get the right rhythm and performance from everybody without having the vfx too involved.
After we filmed our first version of the sequences, we recorded Bradley [Cooper] and Vin’s [Diesel] voices, filming them in the booth as well. James was directing their performances, getting them to act out their sequences for us to reference for our animation. So we ended up with reference shots of them moving and talking as well as their body language. We also used some of their facial performances as well.
James we extremely involved in the animation process. He had almost daily sessions with the animators, directing them almost like he’d direct an actor. He was quite precise about things like eye movement, head turns, everything to get the timing, comedy and emotion right.
So, we used a kind of hybrid approach, taking the best of everything we filmed, recorded and referenced to create our performances.
DS: The complexity and enormity of these types of films continues to amaze me. In your role, working with Marvel as well as working with different vendors, what were the biggest challenges you faced on this movie?
SC: On a film like Guardians, the biggest challenge you face is time. You always feel like you’re never going to have enough time to get things done. It’s just so big. You want everything to be as good as possible, so you always keep fighting for time. From a vfx standpoint, the biggest challenge on the film was getting Rocket and Groot right. But then, there’s everything else going on around them as well. The size of the film, the amount of work, creating that universe, it’s just so huge. Working along with Charlie Wood, the production designer, you have to design everything. There’s environments and space ships you have to design and build. You have to animate and do all the visual effects. You have to keep track of everything.
Marvel has a process where they work to finesse and get the best out of every shot. They may change the cut -- they might change everything at any time. So, you have to keep that in mind and be fluid and open to changes. You have to make it work. That’s how these movies are made. You’re always thinking, “What might change? Then what will I have to get done?” You try your best to stay on top of everything. We had a really good team at Marvel that tracked and followed everything.
In addition, we tried to choose good vendors and make sure they got the job done. We were very lucky on Guardians to work with such a good group of vendors.
DS: Looking as objectively as you can, what visual effects on this movie do you feel audiences and Academy members paid most attention to?
SC: I think people notice and can relate to our digital characters. They feel real. They understand the amount of work that must have gone into making them so believable. But in the end, if you don’t have a good story, all of that visual excellence is useless. I was just lucky enough to do visual effects on a movie that was really fun, that people enjoyed. The characters were so well-written. The worked so well. They felt so real. They didn’t feel like gimmicks. James said, “I don’t want them to look like Bugs Bunny in the middle of the Avengers.” That’s how we always looked at it. Even though we did such a huge amount of work, it was in service to a movie that people really enjoyed.
DS: When you look at the work done by your Oscar-nominated peers, what makes you take notice and say, “That was truly outstanding?”
SC: Well, this year I must say, the work was amazing. At the VFX Bake-off, looking at 10 minutes from the 10 best visual effects films of the year, you think, “My god, there is so much work that went into these movies!” It’s like getting slapped in the face. Everything looks so good. I don’t know how they [Academy members] choose these movies. It’s so hard. But I do notice more and more how the performance of CG characters like in The Hobbit [The Hobbit: The Battle of the Five Armies] integrate so seamlessly with the real actors in the movie. They look as real as the other characters. That’s impressive.
DS: What do you enjoy most about the work you do?
SC: First of all, I’m French, so I’m never satisfied [laughs]. I really like all aspects of the work I do. When you work hard on a picture, and it all works right, and in the end, people like it, that’s pretty cool. Working with all these really clever people around me, that’s really cool too.
Dan Sarto is Publisher and Editor-in-Chief of Animation World Network.