Courtesy of Warner Brothers Pictures
Real-time storytelling: Unreal Engine brings fast iteration to complex shots on Sinners
Set in the 1930s Mississippi Delta, Sinners is a horror film that follows twin brothers who return to their hometown in the Jim Crow South, where they’re confronted by a supernatural evil.
The film involved the shooting of highly technical sequences, including a stitched IMAX-shot music montage that unfolds like a single breath, and a large-scale train arrival that needed to feel period-accurate and cinematic—all under tight production constraints.
To pull it off, the team leaned into a real-time visualization workflow built around Unreal Engine, using it not purely as a previs tool, but as a shared creative space where ideas could be explored, challenged, and aligned upon long before cameras rolled.
We sat down with Sinners Academy Award–nominated VFX Supervisor Michael Ralla and Pepe Valencia, Emmy Award-winning Visualization Supervisor at Baraboom! for a fireside chat that explored how they used Unreal Engine to execute some of the film’s most complex moments. Check it out below.
The film involved the shooting of highly technical sequences, including a stitched IMAX-shot music montage that unfolds like a single breath, and a large-scale train arrival that needed to feel period-accurate and cinematic—all under tight production constraints.
To pull it off, the team leaned into a real-time visualization workflow built around Unreal Engine, using it not purely as a previs tool, but as a shared creative space where ideas could be explored, challenged, and aligned upon long before cameras rolled.
We sat down with Sinners Academy Award–nominated VFX Supervisor Michael Ralla and Pepe Valencia, Emmy Award-winning Visualization Supervisor at Baraboom! for a fireside chat that explored how they used Unreal Engine to execute some of the film’s most complex moments. Check it out below.
Reimagining the filmmaking pipeline
Traditionally, visual effects workflows place artists late in the pipeline—working on shots after most creative decisions have already been locked in.For Sinners VFX Supervisor Michael Ralla, that distance from the story was exactly what he wanted to avoid. “As a compositor, you’re usually the last in the chain,” explains Ralla. “You’re finishing someone else’s shot, without always understanding the original creative intent.”
After being deeply exposed to Unreal Engine through the Unreal Fellowship, Ralla saw a different way forward—one where visualization could happen in real time, close to the filmmakers, and in service of story rather than just execution.
This mindset aligned perfectly with Pepe Valencia, Visualization Supervisor at Baraboom!, whose background as a storyteller shapes his approach to visualization. When Ralla first reached out, Valencia didn’t ask about budgets or schedules.
“Can I read the script?” he asked.
That moment set the tone for the entire collaboration.
“Reading the script for the first time, the big sequence that really stood out to me as something truly unique was what we call the surreal montage, which is when Sammy starts playing in a trancelike state and all of a sudden, we're going through history,” says Ralla.
The surreal montage acts as a cultural séance, blending West African drumming, blues, funk, and hip-hop.
This mindset aligned perfectly with Pepe Valencia, Visualization Supervisor at Baraboom!, whose background as a storyteller shapes his approach to visualization. When Ralla first reached out, Valencia didn’t ask about budgets or schedules.
“Can I read the script?” he asked.
That moment set the tone for the entire collaboration.
Getting everyone on the same page from the off
One of the most mesmerizing sequences in Sinners is a pivotal hallucinatory musical sequence set in a 1930s Mississippi juke joint that sees a blues performance by Sammie (Miles Caton) trigger a time-bending fusion of Black musical history.“Reading the script for the first time, the big sequence that really stood out to me as something truly unique was what we call the surreal montage, which is when Sammy starts playing in a trancelike state and all of a sudden, we're going through history,” says Ralla.
The surreal montage acts as a cultural séance, blending West African drumming, blues, funk, and hip-hop.
Courtesy of Warner Brothers Pictures
It jumped off the page—but everybody imagined it slightly differently.
Ralla, for example, envisioned the characters in the montage as semi-transparent ghosts floating around. “And then I was talking to other people about them, and they were like, what are you talking about?” he says.
The team needed a way to get everybody on the same wavelength—a way to explore the myriad creative possibilities the sequence held. That’s where Unreal Engine came into its own.
It became the common language: a shared, playable version of the sequence. Using Unreal Engine, Valencia began building the sequence from just a few inputs, including the script, a photographed floor plan from production design, a hand-drawn camera path from the cinematographer, and a list of characters spanning generations.
Ralla, for example, envisioned the characters in the montage as semi-transparent ghosts floating around. “And then I was talking to other people about them, and they were like, what are you talking about?” he says.
The team needed a way to get everybody on the same wavelength—a way to explore the myriad creative possibilities the sequence held. That’s where Unreal Engine came into its own.
It became the common language: a shared, playable version of the sequence. Using Unreal Engine, Valencia began building the sequence from just a few inputs, including the script, a photographed floor plan from production design, a hand-drawn camera path from the cinematographer, and a list of characters spanning generations.
Courtesy of Warner Brothers Pictures
Within two days, the first visualization pass was ready. The speed of this turnaround changed everything.
Instead of debating interpretations, departments could now look at the same sequence, move through it, and discuss what was working—and what wasn’t—while there was still time to adjust.
What was more, multiple departments were able to use the work to answer their questions early, from the editors requesting missing shots to the grips planning rig footprint and placement.
It stopped being about ‘previs’ as a deliverable. “It became visualization we were using throughout production,” says Ralla.
The surreal montage was designed to feel like a single take, but it was shot on 65mm IMAX film, with big, heavy cameras; limited film roll lengths; and complex choreography.
By visualizing the sequence in Unreal Engine, the team could identify where stitch points had to exist due to film limits, plan transitions without relying on typical tricks like whip pans, and test Steadicam movement against real physical constraints.
What’s more, they could rehearse timing against music and performance beats, with Unreal Engine helping them spot potential problems early on—rather than finding out about them on set, when it might be too hard or too late to solve them.
Instead of debating interpretations, departments could now look at the same sequence, move through it, and discuss what was working—and what wasn’t—while there was still time to adjust.
What was more, multiple departments were able to use the work to answer their questions early, from the editors requesting missing shots to the grips planning rig footprint and placement.
It stopped being about ‘previs’ as a deliverable. “It became visualization we were using throughout production,” says Ralla.
Identifying problems early
Technical visualization in Unreal Engine made it possible to identify potential issues early in the process, by stress-testing decisions against reality.The surreal montage was designed to feel like a single take, but it was shot on 65mm IMAX film, with big, heavy cameras; limited film roll lengths; and complex choreography.
By visualizing the sequence in Unreal Engine, the team could identify where stitch points had to exist due to film limits, plan transitions without relying on typical tricks like whip pans, and test Steadicam movement against real physical constraints.
What’s more, they could rehearse timing against music and performance beats, with Unreal Engine helping them spot potential problems early on—rather than finding out about them on set, when it might be too hard or too late to solve them.
Courtesy of Warner Brothers Pictures
Because iteration was rapid—often one new version per day—the team could try bold ideas, see what broke, and redesign before costly shoot days.
“If it’s not working, you fail fast,” says Ralla.
Testing and discarding ideas when you’re working with costly IMAX film of limited length is prohibitively expensive. Unreal Engine provided a way to do that exploration before a single roll had been shot.
Speed wasn’t just a pre-production advantage—it mattered on set too.
During the train shoot, Ralla captured reference footage on his phone and sent it directly to Valencia, asking for a quick visualization pass with a CG train added.
Using Unreal Engine and Unreal Engine Marketplace (now Fab) assets, Valencia turned it around fast enough to influence next-day decisions.
It was about more than final pixels—it was about asking the question, "Does this work?"
“I was like, that's great—I love it,” says Ralla. “And we moved on and shot the rest of the sequence.”
That kind of rapid prototyping—moving cameras live, sharing screens, adjusting ideas in real time—made Unreal Engine a creative sandbox where decisions could be tested before committing time and money.
“If it’s not working, you fail fast,” says Ralla.
Testing and discarding ideas when you’re working with costly IMAX film of limited length is prohibitively expensive. Unreal Engine provided a way to do that exploration before a single roll had been shot.
Speed wasn’t just a pre-production advantage—it mattered on set too.
During the train shoot, Ralla captured reference footage on his phone and sent it directly to Valencia, asking for a quick visualization pass with a CG train added.
Using Unreal Engine and Unreal Engine Marketplace (now Fab) assets, Valencia turned it around fast enough to influence next-day decisions.
It was about more than final pixels—it was about asking the question, "Does this work?"
“I was like, that's great—I love it,” says Ralla. “And we moved on and shot the rest of the sequence.”
That kind of rapid prototyping—moving cameras live, sharing screens, adjusting ideas in real time—made Unreal Engine a creative sandbox where decisions could be tested before committing time and money.
Courtesy of Warner Brothers Pictures
Planning complex shots with confidence
Unlike traditional previs, the Unreal Engine visualizations on Sinners didn’t disappear once shooting began.They were used to fill gaps during editorial, explore alternative shots late in production, and help maintain continuity of intent through post.
Editor Michael Shawver even requested visualization shots to help shape the cut—using them as placeholders and planning tools.
In many ways, much of the film’s visual effects work happened before the crew ever stepped on set.
For Ralla and Valencia, leveraging Unreal Engine on Sinners was about creating a clear, shared understanding of the story—early enough that every department could contribute their best work.
“Communicating that creative intent early on, to as many people as possible—it gets us all on the same page,” explains Ralla.
Unreal Engine helped the team move faster, collaborate better, and execute ambitious ideas with confidence—proving that real-time workflows aren’t just changing how films are made, but when the most important creative decisions happen.