PFX SHIFTS INTO TOP GEAR FOR LOCKED

By TREVOR HOGG

Images courtesy of ZQ Entertainment, The Avenue and PFX.

Taking the concept of a single location on the road is Locked, where a carjacker is held captive inside a high-tech SUV that is remotely controlled by a mysterious sociopath. An English language remake of 4X4, the thriller is directed by David Yarovesky, stars Bill Skarsgård and Anthony Hopkins, and was shot in Vancouver during November and December 2023. Post-production lasted four months with sole vendor PFX creating 750 visual effects shots with the expertise of 75 artists and guidance of VFX Supervisor Jindřich Červenka. “Every project is specific and unique,” Červenka notes. “Here, we had a significant challenge due to the sheer number of shots [750], which needed to be completed within four months, all produced in 4K resolution. Additionally, at that time, we didn’t have background plates for every car-driving shot. We distributed the workload among our three branches in Prague, Bratislava and Warsaw to ensure timely completion.” Director Yarkovesky had a clear vision. “That allowed us to move forward quickly. Of course, the more creative and complex sequences involved collaborative exploration, but that’s standard and part of the usual process.”

“The biggest challenge [of the three-and-a-half-minute take introducing the carjacker] was the length of the shot and the fact that nothing in the shot was static. Tracking such a shot required significant effort and improvisation. The entire background was a video projection onto simple geometry created from LiDAR scans of the parking lot. It greatly helped that we could use real-set footage, timed exactly as needed, and render it directly from Nuke.”

—Jindřich Červenka, Visual Effects Supervisor

Previs and storyboards were provided by the client for the more complex shots. “We primarily created postvis for the intense sequence with a car crash, fire and other crazy action,” Červenka states. “We needed to solve this entire sequence in continuity.” Continuity was major issue. “Throughout the film, we had to maintain continuity in the water drops on all car windows, paying close attention to how they reacted to changes in lighting during the drive. Another area of research involved bokeh effects, which we experimented with extensively. Lastly, we conducted significant research into burning cars, finding many beautiful references that we aimed to replicate as closely as possible.” The majority of the visual effects centered around keying, water drops on windows, and cleaning up the interior of the car. Červenka adds, “A few shots included digital doubles. There were set extensions, especially towards the end of the film. Additionally, we worked on fire and rain effects, car replacements in crash sequences, bleeding effects, muzzle flashes, bullet hits, and a bullet-time shot featuring numerous CGI elements.” PFX adhered to its traditional workflow and pipeline for shot production. “We were the sole vendor, which allowed us complete control over the entire process.”

A signature moment is the three-and-a-half-minute continuous take that introduces the young carjacker portrayed by Bill Skarsgård. “The biggest challenge was the length of the shot and the fact that nothing in the shot was static,” Červenka remarks. “Tracking such a shot required significant effort and improvisation. The entire background was a video projection onto simple geometry created from LiDAR scans of the parking lot. It greatly helped that we could use real-set footage, timed exactly as needed, and render it directly from Nuke. Window reflections were particularly challenging, and we ultimately used a combination of 3D renders and compositing cheats. When you have moving car parts, the window reflections give it away, so we had to tackle that carefully.” Not surprisingly, this was the most complex shot to execute. “The three-and-a-half-minute shot involved 12 artists, nine of whom were compositors. Working on extremely long shots is always challenging, so dividing the task into smaller segments was crucial to avoid fatigue. In total, we split it into 96 smaller tasks.”

“[W]e conducted significant research into burning cars, finding many beautiful references that we aimed to replicate as closely as possible. … A few shots included digital doubles. There were set extensions, especially towards the end of the film. Additionally, we worked on fire and rain effects, car replacements in crash sequences, bleeding effects, muzzle flashes, bullet hits, and a bullet-time shot featuring numerous CGI elements.”

—Jindřich Červenka, Visual Effects Supervisor

Background plates were shot by Onset VFX Supervisor Robert Habros. “His crew did excellent work capturing the background plates,” Červenka notes. “For most car rides, we had footage from six cameras covering 180°, allowing us to stitch these together to achieve the appropriate background width or use the correct angle. Additionally, we had footage of an extended drive through the actual city location where the story takes place, so everything was edited by a visual effects editor. We simply synchronized this with the remaining camera recordings and integrated them into the shots.” The greenscreen was set at two distances. Červenka explains, “There was a closer, lower one and an entire wall a few meters away, approximately two meters apart. Although I wasn’t personally on set, this setup helped create parallax since we couldn’t rely on the car’s interior. For the three-and-a-half-minute shot, we had separate tracking for the background and interior, where all interior walls were tracked as moving objects. Aligning these into a single reliable parallax track was impossible.”

“[W]e use an internal application allowing real-time viewing of shots and versions in the context of the film’s edit or defined workflows, enabling simultaneous comments on any production stage or context. Imagine having daily reviews where everything created up to that point is assessed, with artists continually adding new versions. In these daily sessions, everything was always thoroughly reviewed, and nothing was left for the next day.”

—Jindřich Červenka, Visual Effects Supervisor

There is an art to painting out unwanted reflections and incorporating desirable ones. “The trick was that the studio-filmed interior had no glass in the windows at all,” Červenka states. “Reflections, raindrops and everything visible on the windows had to be added digitally. Shots from real exteriors and cars provided excellent references.” Fire simulations were time-consuming. “We simulated them in high resolution, and due to continuity requirements, we simulated from the initial ignition to full combustion, with the longest shot nearly 600 frames long. This was divided into six separate simulations, totaling about 30TB of data.” Digital doubles were minimal. “Throughout the film, there were only two digital doubles used in violent scenes. We didn’t have to create any crowds or face replacements.” A CG replica was made of the SUV. “We had a LiDAR scan of the actual car, which served as the basis for the detailed CG version, including the interior. Only a few shots ultimately required this, primarily during a scene where another SUV car was initially filmed. We replaced it, and in two cases, we replaced only parts of the car and wheels to maintain real contact with the ground. There was a bit of masking involved, but otherwise, it went smoothly. The interior was mainly used for window reflections in wide shots from inside the car.”

“We primarily created postvis for the intense sequence with a car crash, fire and other crazy action. We needed to solve this entire sequence in continuity. Throughout the film, we had to maintain continuity in the water drops on all car windows, paying close attention to how they reacted to changes in lighting during the drive.”

—Jindřich Červenka, Visual Effects Supervisor

“The greatest creative and technical challenge was reviewing shots in continuity within a short production timeline and coordinating across our various offices,” Červenka observes. “Each shot depended on others, requiring numerous iterations to synchronize everything. For projects like this, we use an internal application allowing real-time viewing of shots and versions in the context of the film’s edit or defined workflows, enabling simultaneous comments on any production stage or context. Imagine having daily reviews where everything created up to that point is assessed, with artists continually adding new versions. In these daily sessions, everything was always thoroughly reviewed, and nothing was left for the next day. We avoided waiting for exports or caching. Everything needed to run smoothly and in real-time.” Complicating matters was that Červenka joined the project only after editing had concluded. “I had to quickly coordinate with teams distributed across Central Europe, grasp the intricacies of individual scenes and resolve continuity, which required extensive and precise communication. Thanks to our custom collaboration tools, we managed to streamline this demanding coordination successfully, and we delivered on time. But it definitely wasn’t easy!”

Watch PFX’s brief VFX breakdown of the opening scene of Locked. The scene sets the tone for the film with a gripping three-and-a-half-minute single shot brought to life on a greenscreen stage where six crew members moved car parts in perfect sync. Click here: https://www.facebook.com/PFXcompany/videos/locked-vfx-breakdown/4887459704811837/