A deep dive into the on-location chopper flying, bluescreen shooting, and final digital VFX work by DNEG for this and many other huge scenes in the film.
UPDATED WITH NEW BEFORE/AFTER IMAGES!
At one point in Louis Leterrier’s Fast X, Dominic Toretto (Vin Diesel) uses the wreckage of two crashed choppers–still attached by wires–as a weapon against his adversaries.
This ‘nunchuck’ is one of many outlandish moments in the film, and one in which the visual effects team, led by production visual effects supervisor Peter Chiang, had a key role.
In this case, DNEG helped orchestrate the moment, as it did in several other big scenes for the Rome runaway bomb, various cannon car scenes and the Portugal highway chase (which involves cars, helicopters and even a large military plane).
befores & afters asked DNEG visual effects supervisors Aleks Pejic and Francois Lambert to break down just some of their biggest shots.
You’ll learn what was filmed for real, how a new array car was used, the LiDAR that took place, what bluescreen filming was done, and where digital visual effects took over.
b&a: For the shots of the Rome ball bomb, tell me about actually building that ball asset? What were some of the approaches you took to any mixing or matching of the real ball bomb with the CG one?
Aleks Pejic: The prop department created several versions of the bomb and they were used on set as a lighting reference. The original plan was to hopefully use the prop in final shots, but due to the way the rig had been built we knew quite early on that we’d need to replace it with a CG asset. Because the prop was being dragged on rails, the motion was very linear which wasn’t the look that production VFX supervisor Peter Chiang and director Louis Leterrier had imagined. So, the plan from the beginning was to create a fully CG asset, but to reference some of the motion and lighting from the on set shoot with the prop.
What we learned as we got into the sequence was that, because the ball was rolling down the hill for quite a long time, it was going to go through certain phases of damage. To start with, damage from going through buildings and colliding with roads, etc. But then also from the gas pump explosion when it catches fire. All of this would create damage to the surface of the bomb, which Peter wanted to demonstrate as we progressed through the sequence. That triggered the creation of several different bomb variations and different looks. The original asset would look one way in the lighting conditions, and then completely different with all the charcoal, burnt sections, and scratches.
b&a: How were sections of streets for Rome (or the filming location) built up, either for CG shots, or extensions, or to aid in compositing? How were these assets incorporated into DNEG’s pipeline?
Aleks Pejic: The Rome sequences were shot in different locations–some in Rome and some in Turin–and, as the story had a particular pace, some of the locations had to be compressed distance-wise. So, the final look is not necessarily true to life. We combined together the two shoot locations to create the Rome environments, either by altering the Turin plates and adding Roman features, or by enhancing the Rome plates.
Creating the environments varied from shot to shot. Sometimes we used ariel plate photography to reconstruct the geometry and sometimes we created buildings in full CG, depending on the camera moves and how close the shot was to those buildings.
Our DFX supervisor, Ben Cowell-Thomas, was on set in Rome with Peter and they made sure every location was LiDAR’d and photographed. Peter also did very specific helicopter passes for us in order to gather the references needed to reconstruct particular areas and sections of Rome for the big wide establishers.
We used a combination of all the available tools for environment builds to get the sequences looking as photoreal as possible.
b&a: There’s a shot where it breaks a bus apart in two—can you discuss what was done here in live-action and how you got to a final VFX shot?
Aleks Pejic: Again, for this sequence, the bomb prop was replaced with a fully CG asset and we enhanced it with the roll damage, dust, and debris to make it more believable. The bus was shot practically, but it was made out of polyester and that was fairly visible in the sense of its colour, and the way the damage and debris behaved. So, we enhanced what was there in the plates, adding CG elements to make it more true to life.
b&a: For the shots of the final explosion and shockwave, what tests did you do at first to get the desired look?
Aleks Pejic: We started by referencing both nuclear and underwater explosions throughout history. We quite quickly realised that neither reference on its own would work for the scale and look we needed for the particular shot. We would either end up with only water or, if it was an earth explosion, just the debris and the soil without the water. So, there were a fair amount of creative challenges to find the right look. In the end, we took some of those real life references and, with direction from Peter and Louis, created the final explosion which was a hybrid of both.
As for the destruction around the explosion, we actually expected to do significantly more damage than we did in the end. From our references, we learned that these kinds of explosions generate a lot of dust, and visually that dust overtakes everything else that’s underneath it. So, building the destruction became almost secondary to compliment the look, rather than driving it. The final look was really the overwhelming dust that is created by these big explosions.
For the rest of the shockwave sequence, we looked at real life references of tornadoes and hurricanes that reach up to 150 mph. We referenced what would happen to the trees, the buildings and the water, and then tried to recreate something similar that would fit into the shots for the sequence.
b&a: Can you break down the different elements of that explosion and shockwave—including what city assets, water, debris and other elements—and how the explosion was simulated? What would you say was the way you ensured you had the right balance of all these things?
Aleks Pejic: The explosion and shockwave were created in Houdini with lots of different passes to determine the different types of debris, building destruction, the water simulation, spray and waves, and the dust from the ground. The sequence was a combination of a lot of different passes that then went to comp to generate the really complex look.
To find the right balance we used our real life references, but there was also a certain level of artistic guidance from Peter and Louis. They always wanted the actors and story points to be visible for the audience, so we deviated a little bit from certain references in order to make sure that the shots were driven by the story.
b&a: The emergence and chase involving the cannon car in the quarry area in Portugal is great—for that part of the chase, what were the different elements that would make up the final shots, from plates, to bluescreen photography, environments, CG cars and fire and explosion elements?
Francois Lambert: Regarding the blue screen composite process, we utilized a 12-camera array mounted on a modified car, an upgrade from the 9-camera array used in Fast 9. The purpose was for the array car to follow the hero car’s path extensively. For example, during second unit shoots in either Italy or Portugal, the array car driver would precisely replicate the movements of the stunt cars, capturing a 360-degree view of the car’s surroundings. It went as far as driving through a large puddle of water to match the action of Jakob’s El Camino jumping out of the mine tunnel and into the water in the Portugal scene.
This footage was then sent overnight to the blue screen set in London. There, the lighting direction and position of the blue screen set were adjusted to align with the second unit footage. The main cast would then be filmed driving in the blue screen car buck. Finally, at DNEG, the footage would undergo compositing to seamlessly integrate the actors into the desired environment.
This process allowed us to create realistic and immersive blue screen composites, ensuring a seamless integration of the actors into the surrounding environments captured by the array car during filming.
b&a: Tell me about the environment build for the highway chase, again, how did you approach building this asset to use for all CG shots, extensions and whatever else you needed it for?
Francois Lambert: To bring the Portugal car chase sequence together, we filmed in various locations across the country, including Lisbon’s harbour, a quarry in Alenquer, and a highway in the Douro Valley. Although these locations were visually stunning, we needed to seamlessly blend them. For instance, we incorporated highway scenery into wide shots of the quarry to make them feel closer. To achieve this, our team undertook the monumental task of gathering extensive LiDAR data, capturing the entire stretch of the quarry and highway. This effort allowed us to create a detailed environmental mesh. The highway was divided into four zones (blue, green, black, and orange), and our mesh matched each zone. We utilised this data for layout and match move process.
In the middle of the sequence, a plane carrying Dom and the Charger enters the scene. In the story, the plane is unable to find a landing spot, leading Dom to drop his Charger onto the mercenary cars. However, the actual location for this event was relatively flat. To overcome this challenge, we surveyed the surroundings and captured the landmark mountain range known as Serra da Estrela. Using long-range LiDAR technology, we collected as much data as possible from the base of the mountain and completed it with a helicopter photogrammetry shoot. The environment team then created a CG mountain and seamlessly integrated it into the highway environment. This aspect presented a significant challenge for us to overcome.
Another challenge happened later in the sequence as two helicopters’ carcasses cause havoc on the highway. The team had to replicate an entire piece of the highway and bridge in order for us to destroy pieces of it. In that beat, the real location and full CG environment live side by side seamlessly.
b&a: In that highway chase, in general, what ways was DNEG controlling CG cars, in terms of matching animation to real cars? ie. crafting believable, but also sometimes high action, driving? What did any pod or stand-in cars or car frames help with here?
Francois Lambert: During the shoot in Portugal, the team strived to capture as much of the action as possible using real stunt cars. Each of the hero cars, including Dom’s Charger, Jakob’s El Camino, and Dante’s Fairlane, had their respective stunt doubles for the pursuit scenes. We had a variety of mercenary cars, such as BMWs, Land Rover’s Discovery, Mini Coopers, and FJ Cruisers, as well as nondescript vehicles for the highway scenes. For each car, we had a corresponding CG version that we could seamlessly switch to when needed.
One particular challenge we faced was maintaining continuity as the sequence progressed and the cars sustained damage. To address this, each CG asset had multiple variations to depict the evolving state of the cars over time. We frequently replaced cars as the editing progressed to ensure continuity was preserved. In fact, in every shot, a matchmove of the cars in the plates were executed for each hero car. This allowed us to add additional damage to a fender or remove scratches that were meant to occur later in the timeline. We also introduced more cars to heighten the sense of danger when Dom drove into oncoming traffic. Additionally, we replaced or added mercenary cars as required by the storyline.
Even for the helicopter smash, a practical empty Charger was projected from the top deck of the highway onto the lower deck. The car crashed beyond repair, but provided a great reference for how it would arc during its massive jump. With a wide range of matchmoved action footage, including car driving, drifting, swerving, and ‘flying’, our layout and animation team had all the references they needed to create the full CG shots.
In the end, most cars were replaced or enhanced throughout the sequence seamlessly without the audience ever knowing about it.
b&a: When the two helicopters are grabbed by wires and ultimately crash, can you discuss some of the conversations you had about physics—that is, obeying them as much as possible in terms of flying, crashing, explosions, but also making it as exciting as possible?
Francois Lambert: In this part of the sequence, two helicopters ascend on each side of a highway bridge, aiming to shoot harpoons at Dom’s Charger and throw him off the bridge. However, Dom retaliates by activating his NOS, causing the helicopters to collide in mid-air and crash.
We were fortunate to have two real helicopters on set, piloted by Fred North and his skilled team. We shot with them for a few days in Portugal around the city of Vila Real. They were able to perform a good amount of the stunts within a safe distance of each other, after which we took one helicopter away for the moment they had near misses, then both of them were grounded for the climatic moment in which both helicopters crashed together. This allowed us to study their movements and manoeuvrability, which proved valuable for creating the final blend of real and CG helicopters seen in the movie.
Our VFX animation team used the real helicopters as a reference point to ensure realistic physics, weight, and flight paths in each shot. After completing the CG animation for the helicopters, Fred was invited back to the screening room to provide guidance on the movements a real helicopter would make under various forces, such as being pulled and tugged or positioning itself to lift a car and even how a helicopter would crash if pulled. This allowed us to tweak our animation one more time before sending it to lighting. This attention to detail resulted in an exciting and authentic portrayal of the helicopters seen in the film.
The subsequent beat, that we called the ‘nunchuck sequence’ presented its own set of challenges. Dom utilizes the wreckage of the crashed helicopters, still attached by wires, as powerful bludgeoning weapons against the mercenary cars. The Charger drifts and spins, igniting the helicopters and causing destruction as it manoeuvres. On set, under the direction of production VFX supervisor Peter Chiang, we devised a plan for the Charger to spin and roll the wires like a yoyo, generating speed and centrifugal force to eliminate the cars around him. This proved to be a complex – if not the most complex – animation task, requiring us to carefully balance the visual excitement and danger while maintaining the weight and realism of the vehicles involved. Our animation team worked diligently, creating multiple iterations in collaboration with the FX and lighting teams to ensure timely delivery of the final fiery, debris-filled sequences.
b&a: In this highway sequence (and in the film in general), there seems to me to be such a great use of atmosphere, dust, sparks, flying debris etc to help sell so many of these frenetic shots…what did you find worked and didn’t work when adding in those kinds of elements?
Francois Lambert: In general, our primary objective for the highway sequence was to ensure that the FX remained faithful to the real photography. We closely studied how the actual stunt cars lifted dust and dirt in the quarry scene, as well as how the Charger generated white tire smoke while drifting. Realism was our key focus throughout. Even when some stunts didn’t go as planned, we had valuable reference footage.
For example, when Dante pushes Dom’s Charger into oncoming traffic after the tunnel grab scene, the Charger was intended to land wheels down on the lower deck of the highway but ended up flipping onto its roof. Due to time constraints, we made the decision to recreate the action using CG. We were able to retain much of the concrete destruction from the original shot, replacing the cars and enhancing the scene with FX elements such as smoke, dust, and concrete debris, using the original footage as a reference.
Another notable instance is Jakob’s car flipping over and crashing into oncoming traffic, creating a path for Dom. This scene on the Portugal set involved launching an empty El Camino into a group of mercenary cars, triggering a massive explosion. While some elements like fire and debris were practical effects, Portugal’s strict no-fire policy, due to extreme temperatures and the risk of wildfires, limited the use of real fire. The practical FX team managed to incorporate a brief burst of fire that extinguished quickly. This provided an opportunity for our CG FX team to supplement, match, or extend the fire effects to achieve the desired intensity.
The most significant FX undertaking in this sequence was the ‘nunchuck’ scene. It involved complex CG FX setups for the helicopter crashes and the Charger dragging them across the highway. Our team meticulously crafted a setup using video and photo references, ensuring that the helicopters sustained continuous damage, leaving behind a trail of debris, gasoline leaks, fire, sparks, embers, and significant structural damage to the highway along their path. We also developed multiple asset variations of the helicopters at different stages of destruction to reflect the progress in the timeline.
Throughout the production, our dedicated team worked tirelessly to bring these FX elements to life, maintaining a balance between realism and spectacle. The combination of practical effects, CG enhancements, and careful attention to detail allowed us to deliver a visually stunning and immersive experience for the audience.
