Back in 2021, Stéphane Nazé walked us through Framestore’s visual effects work on The Tomorrow War. Since then, he’s contributed to Fantastic Beasts: The Secrets of Dumbledore and Guardians of the Galaxy Vol. 3. Today, he returns to discuss his latest collaboration with director James Gunn and VFX Supervisor Stéphane Ceretti on Superman.
Loïc Mireault started his journey in visual effects in 2014 at Framestore. Since then, he has contributed to a wide range of projects, including all three Fantastic Beasts movies, Paddington 2, His Dark Materials, and the Rebel Moon saga.
Kevin Sears began his visual effects journey in 2007 at Digital Domain, working on Speed Racer. In 2011, he moved to Method Studios before joining Framestore in 2017. Over the years, he has contributed to major projects including Fantastic Beasts: The Crimes of Grindelwald, Project Power, Army of the Dead, and Guardians of the Galaxy Vol. 3.
Can you tell us about your collaboration with James Gunn on Superman? How did he influence the creative process and visual choices?
Stéphane Nazé: James Gunn had a strong vision, and storytelling was the key for him. But more than anything else, he is a very collaborative director and very openminded to new ideas. He genuinely expected Framestore to come with inputs and not just simply execute tasks. With a director like him, you are not just trying to define what he wants; but you are pushing the quality and expectations quite far, as James has a solid understanding of the VFX process.
How did you work together with VFX Supervisor Stéphane Ceretti, and how did you combine your efforts to bring the visual universe of Superman to life?
Stéphane Nazé: Stéphane C. and I have known each other for a while, and the key to our collaboration is transparency. It was essential to be clear about what we could or couldn’t do and what was or wasn’t possible. I would say our work together could be summarized by constant, fluid communication. Stéphane Ceretti trusted our expertise and expected strong creative input from us at Framestore, not just execution.
How did it feel to enter the DC Universe for the first time with this project?
Loic Mireault: It felt great! The impact of visual effects is always huge for this kind of project, and we felt Framestore’s work on Krypto, the SupermanRobots, the Engineer, and the Fortress of Solitude really stood out!
Stéphane Nazé: We felt very lucky and were thrilled to be part of the adventure, especially since Superman is such an iconic character.
Krypto, the Superdog, is an iconic character. What were the biggest challenges in bringing him to life in photorealistic form while maintaining his “super” qualities?
Loic Mireault: The client came to us with a very well done postvis. Even though all the animation had to be redone with the final Krypto asset, we knew we could stick to the main framing, beats, actions and energy, since James Gunn had previously approved it. The main challenge was to break down the actions, intentions, emotions seen in the postvis. This was followed by the exercise of finding an Ozu reference, or other real dog footage from the internet, that was best suited for each action. Matching these references guaranteed that Krypto moved and behaved like a real dog. Finding good references is the key step in the process! Animating behaviour without reference can easily look wrong to the audience’ and make the dog feel uncanny. The human eye has been so used to seeing dogs for thousands of years that it is extremely difficult to make it feel real, and even harder when the director requests the character to have specific emotions or to do specific actions for storytelling reasons.
How did you incorporate James Gunn’s own dog, Ozu, into Krypto’s design? Were there specific elements of her behavior or appearance that were reflected on screen?
Loic Mireault: Krypto is based entirely on James Gunn’s dog Ozu. Like many dog lovers, James had tons of clips of his dog on his phone. So when we asked him for video references of Ozu, he sent us close to an hour of Ozu’s footage in many different contexts, which was essential to capture the essence of Ozu’s behavior and personality.
James was clear from day one: he wanted Krypto to be Ozu. Our goal was to ensure James would recognize his own dog in Krypto’s performance. We basically interpreted those Ozu’s references as if they were an hour long Krypto movie, with the goal of mimicking Ozu’s specific facial gestures, behaviors, right down to matching his iconic asymmetric ears!
Krypto is a dog with superhuman powers. What animation techniques were used to convey his strength while maintaining natural and believable movements?
Loic Mireault: It’s worth mentioning that Krypto was a fully keyframe animated character. No Motion Capture was involved in the process, and there was no real dog, puppet or animatronic on the original footage to base our animation on. Since we had nothing to match from the plate, Krypto’s performance was developed and designed from scratch by the animation/postvis team in post-production, with obviously, the crucial creative input from James Gunn.
Another important aspect to mention about Krypto is that James Gunn wanted Krypto to feel, move and act like a real dog. Even though he’s a superdog, he wasn’t meant to be more intelligent, or acting differently as a normal dog. But since he is a superdog, we obviously had a lot of very challenging unrealistic jumps and heavy body mechanics shots with Krypto. Our approach was to ground these supernatural actions by always sticking to real dog footage and poses.
The flight sequences required a different approach since the reference just doesn’t exist! Dogs, unlike humans, rarely walk in a perfect straight line. Probably since they do not have to be in a specific place, at a specific time. They live more in the present, sniffing or walking around, looking for food or following another animal path using its scent. We felt Krypto’s flight path shouldn’t feel as clean and elegant as Superman.
We also found that Superman’s flight pose, with straight, elongated limbs, didn’t translate well to Krypto’s canine anatomy and looked unnatural. Instead, we developed a flight style that felt more authentic to the character.
The Fortress of Solitude is an iconic location in the DC Universe. Can you talk about how you approached creating it entirely in CG, and what specific techniques you used to make the crystals so impressive?
Kevin Sears: The Fortress exterior and interior started from an amazing set design on a stage. We honored the set photography by keeping as much as possible and approaching this as an extension build. However the needs of some of the exterior shots with it rising and settling into place necessitated that it was full cg when viewed from outside. When planning the Fortress asset we knew it would require many crystal sizes and variations. We ended up making 54 different kit crystals that were all very detailed. Some of those are as big as the Empire State Building! Then we carefully arranged them into the main silhouette of the Fortress concepts and then filled in the rest with a total amount over 6,000! Each one had controls to animate in Animation and FX for adding subtle details of the action. For crystals that came close to the camera, we procedurally had FX generate the shattered interior cracks to give complex refraction on these clear objects. Then, we added FX snow and textures to integrate them with a full CG landscape and snow simulation.
For the interior shots we continued with this approach and applied it to more unique crystals to match the set photography. There is a large wall of crystals behind the SuperComputer. This was animated in the same way to allow it to open and slide the crystals to allow the sunlight to heal Superman. All the 16 months on the show was spent optimizing and managing the crystal renders. We did two render passes to capture refraction details with a limited number of bounces of light and then a final render with reflections on top that gave us the final result. At 4K resolution it was days of rendering. Some shots seen in the trailer took each frame around 7 days on our highest cpu and ram requirements.
What were the biggest technical challenges in creating the Fortress of Solitude, particularly regarding modeling, texturing, and lighting?
Stéphane Nazé: The Fortress of Solitude has been one of our biggest challenges, primarily a technical one. We approved quite quickly the look of the Fortress but we spent most of our time trying to “optimize” this asset. The render times were enormous… The initial approach was to say “let’s have no limit and create the most beautiful Fortress of crystal, but when the “look” was approved, we faced the challenge of actually rendering it. The asset contains 6000 pieces of crystals with complex structures inside of each piece, being reflective and refractive.
Each shot was quite unique in the approach, some shots (like the top down view in the opening sequence) were fully CG and we rendered each frame in full resolution, but on shots with minimal camera movement we split in 3 layers. The background ones were one frame projection with more simple geometries, the midground ones were sometimes a mix of projection with an addition of reflections/refractions and the foreground ones were fully CG. Obviously shots with no camera movement at all were single frame render. It was impossible to render all the frames in all the shots. On some shots, we even upscaled the renders to save time. Not all the 6000 pieces were unique, we created 50ish unique pieces in modelling, textures then we used the instance process to duplicate them. But even with this huge optimization effort, reflection and refraction are never render-time friendly!
The battle sequence in the Fortress involves The Engineer and robots. Can you explain the challenges of creating this scene, particularly with The Engineer and the FX effects associated with her?
Loic Mireault: That sequence for sure brings quite a lot of challenges for the team, but was a lot of fun to design! Due to her nanite suit, we had to fully replace María Gabriela de Faría (The Engineer) body for a fully CG suit. While we stick closely to her original performance, the CG suit gave us freedom to slightly change her arms and hands positions for better interaction with the robots she was fighting. The stunt actors were then removed from the plate and replaced. The Robots were also keyframes-animated, and we didn’t necessarily match the stunt actors’ performance, but we still kept the same timing and framing.
The workflow for the robots’ destruction was also quite challenging. We had to go through a first pass of animation to determine what robot will be cut where. Rigging would then create a robot variant for each of them with that specific cut. Our FX artists will then simulate a very precise cut with all the small debris and sparks and then our CFX artists would add their capes being shredded.
The robots and Luthor glasses were reflective and we had to animate things we were not seeing on screen to ensure their reflections would appear correctly in the surfaces visible in the shot.
The Engineer has nanite-based blood. Can you talk about the innovations you implemented to represent this complex concept in a visually convincing and realistic way on screen?
Kevin Sears: The Engineer was a character based FX that Framestore was awarded as the lead vendor. She started with a highly detailed digidouble with a complex groom of braids and an amazing holographic costume material that we analyzed from a sample in the studio. This suit had practical double layer details like a 3D movie poster. We couldn’t believe it was real so it became a fun jumping off point for the artists to see and really inspired the CG team to take this character to the next level. Concepts from DC showed the multitude of her abilities and powers to transform her suit and skin into anything the script described. We decided to simulate the costume as a traditional Creature FX pass after Animation. This added a crucial reality to the suit behaving like a real skin tight costume. After this step, the FX team recreated her suit and mesh with primitive cube geometry to allow it to peel away and have interior thickness. During the fight sequence with the SupermanRobots, the Engineer’s body is full cg with subtle behaviours of spike and wave motions across her suit. She pulsed and became a living simulation as she attacked them with her spinning blade arms. Those blades were also a series of small nanite cubes that had an unique fan pattern in their layout and motion blur for a comic book graphical aesthetic.
Later in the sequence, we have the Engineer hack the SuperComputuer and she forms a headdress of nanite spikes across her neck and face. These were again placed by FX across her face track geometry and animated to appear and become brighter with energy light increasing. The tendrils of long nanite geos were connected to her body to make the interaction with this scene! Ultimately there were rocket thrusters, ripped nanite faces, spinning blades, bazooka cannons, and nanite swarms as the wide range of abilities the FX and Asset teams created for The Engineer.
Were there any memorable moments or scenes from the film that you found particularly rewarding or challenging to work on from a visual effects standpoint?
Loic Mireault: I don’t have a specific shot or scene in mind, but it is always extremely challenging to bring such a hero asset like Krypto to life. Not only from an animation point of view, but also on an asset level. All the details on the fur such as small dust particles and wet fur due to melted snow, in addition to the muscle simulation, snow and wind interaction. Without all that, Krypto wouldn’t have felt nearly as integrated into the world
Stéphane Nazé: There are many of them, especially for this movie! For creative reasons, I would say the close up shots of Krypto in the opening sequence, because we pushed quite far the quality, the details and we got the “wow” effect at the end. There is also the Fortress of Solitude, the shots, from my perspective, are beautiful. They have been super challenging creatively and technically.
Looking back on the project, what aspects of the visual effects are you most proud of?
Stéphane Nazé: Framestore has been lucky enough to work on two very iconic assets. Krypto and the Fortress. But more than anything I am very proud of the consistency of our shots! Which is the key for not being disconnected of the action
What’s the VFX shots count?
Stéphane Nazé: 540 shots
What is your next project?
Loic Mireault: Supergirl
Stéphane Nazé: Supergirl 🙂
Kevin Sears: Supergirl
A big thanks for your time.
// VFX BREAKDOWN
// TRAILERS
WANT TO KNOW MORE?
Framestore: Dedicated page about Superman on Framestore website.
Stéphane Ceretti: Here’s my interview of Production VFX Supervisor Stéphane Ceretti.
© Vincent Frei – The Art of VFX – 2025
