Into the Vortex

Science-fiction crime drama Vortex – about a police officer attempting to change the past – is the first French series to use virtual production. DQ speaks to Fix Studio VFX producer Cédric Herbet about the demands of using this emerging technology.

Blending family drama, a crime story and innovation in front and behind the camera, Vortex is the first French series to make use of virtual production.

Set in 2025, the story follows Ludovic, the police captain in the city of Brest. Twenty-seven years earlier, he lost the love of his life, Mélanie, in what appeared to be a mundane accident.

But while studying a virtual reality (VR) reconstruction of the beach crime scene, Ludovic stumbles upon a time warp that turns his life upside down: he is able to communicate with Mélanie just a few days before her death in 1998.

As he attempts to save her life in the past, Ludovic risks losing his life in the present – as well as his wife Parvana and their son Sam.

To solve the crime, Ludovic works in a VR room that reconstructs the beach – and brings Melanie back to life. In making the series, the real beach location was shot and scanned thousands of times and rebuilt in a virtual setting inside a studio, ensuring the same conditions were replicated every time. Then on set, the production design and VFX departments worked in tandem to recreate every element of the beach, using props and huge video screens that project the background, including the ebbing tide, in real time as the actors perform in front of them.

Other series to have used virtual production include Star Wars drama The Mandalorian and Netflix’s 1899.

Produced by Quad Drama, the six-part series debuted on France Télévisions channel France 2 earlier this year and is now airing worldwide on Netflix following a deal with distributor France TV Distribution.

Written by Camille Couasse and Sarah Farkas, it is directed by Slimane-Baptiste Berhoun. The cast is led by Tomer Sisley, Camille Claris, Zineb Triki and Eric Pucheu.

Here, Cédric Herbet, VFX producer at Quad Group’s Fix Studio, reveals how elements of the series were conceived, designed and realised with virtual production – large video walls used to project authentic backdrops behind the actors in real time.

VR is baked into the story premise. What were your ambitions for the series from the outset?
The opportunity to work on a science-fiction TV series was the primary source of motivation for the teams. It’s always exhilarating to be part of a project where one is asked express their creativity, especially when it involves presenting a vision of the future.

However, before being a technical demonstration, VFX must first and foremost serve the direction. Even more so for science fiction, the best special effects are always those that go unnoticed.

Did you identify any challenges early on in development?
The main challenge was not in convincing the team to implement means and new technologies to serve the filming, without ever having experimented with them, but to get the team to truly collaborate differently by changing their preparation and filming habits.

In France, due to the rarity of projects like Vortex, it’s not so conventional to grant the VFX team access so early in production, to play such a proactive pivotal role.

Can you recall your initial discussions about how you would film the series?
In the story, in France 2025, there is a VR room where the police officers, using a 3D scan shot with drones, can revisit the initial moments of a crime scene and upload it as many times as needed to conduct the investigation.

In Spring 2021, while we were listening to the pitch, it immediately became evident that Vortex was in complete alignment with the new possibilities such as photogrammetry, virtual production shooting and real-time 3D. It’s as if the script was imagined by those who created these techniques.

Just as the forensic police of the future will do, we will use the same technologies for production and filming.

Why did you decide to use virtual production? Were other methods considered?
It was perfectly suited to serve the story and the narrative of the project. No other methods were considered. Of course, green screens and matt paintings were occasionally used for conventional VFX in scenes other than the beach.

But while the virtual studio allowed us to be creative and innovative, it primarily proved to be suitable for the practical challenges of a shooting schedule.

The first objective was to organise the filming of all the scenes where this virtual crime scene takes place, an unchanging backdrop at ‘magic hour,’ in which the main character meets their beloved. We had to contemplate a shooting schedule with a constant concern for maintaining a strict alignment between the same time, same sunlight, same sky/weather conditions and tidal coefficients, which is a luxury that no one would have dared to produce live/on camera with so many degrees of difficulty.

Virtual production then allowed us to shoot on the same photorealistic exterior set for several days, enabling us to maintain perfect continuity. The risks due to weather and tides were under control.

Therefore, the virtual production truly brought a tangible solution to the most factual objective of a project, its financing. It introduced a new variable in the pursuit of that ever-sought balance in controlling and anticipating production costs.

Virtual production is used to recreate a key location, a beach. How was this achieved during pre-production and then on set?
Corsen Beach is located in a bay at the tip of the Finistere in Brittany. As in the series, we employed a similar technique to ‘scan’ it and recreate it virtually.

For the first time, we used a drone to perform a complete photogrammetry of the area. A set of photos formed the basis for obtaining 3D volumes and their natural textures. We collected all the topographical data of this bay, including its complete environment, such as beaches and cliffs.

We recommended scanning at low tide to capture as much material as possible. This allowed us to recreate and have control over the movements and sea’s ebb and flow. Around 18,000 shots were taken.

A second step, known as retopology, was then performed, and all of the raw data was consolidated into a 3D scene with all information pertinent to the scale included.

The third step was the preparation of this 3D scene of the bay. The goal was to make it usable in real time in Unreal Engine. The three areas designated for the performances, which were identified in advance by the director, were optimised in quality within the overall setup for this location.

The 3D scene was then lit identically to the live sequence of the crime scene, as it had been filmed under natural conditions at Corsen.

How did you work with director Slimane-Baptiste Berhoun?
Vortex was our first collaboration with Slimane. We first had to gain his trust, as this project involved many challenges: an ambitious script, the expectations of quality set by France Télévisions, the director’s treatment and intentions, and Quad Drama’s decision to shoot about 30 scenes in virtual production and to be the first in France to experiment with this technology, over a 10-day shoot.

The difficulties and constraints were also always presented to him, not to highlight impossibilities or induce stress, but rather to ensure honesty remained a cornerstone of our collaboration. This was done with the aim of improving and finding alternatives.

Did the fact that audiences know Ludovic is in a VR programme mean there was some leeway with the realism of the beach you created in virtual production, or did you always want to make it as real as possible?
From the very first episode, viewers will perceive this VR room as an augmented reality playback tool. But it’s not the absolute reality; it’s an empty room where we hit ‘play’ on a high-tech recording. The ‘Melanie spectre’ from another time then appears there.

The technology offered in the VR room is version 1.0. Display flaws, bugs or artifacts intentionally requested and embraced by Slimane are naturally accepted by viewers because they understand the setup.

As a result, if there were any flaws in the 3D capture, instead of attempting to cancel them, perhaps we also customised them in post-production. However, it’s also important to note that our 3D scene allowed us to shoot additional shots in a photorealist beach setup.

Is there a secret to making something computer-generated look completely believable?
First and foremost, one should always seek on-camera options, and then consider CGI if this would be more relevant in terms of visuals, cost and scheduling.

One should always strive for on-camera elements, whether in XR [virtual, augmented or mixed reality] or on green screen. The importance of the set design is also paramount. This applies to foreground elements as well as all elements in close proximity to the actors.

What was your experience using virtual production? What lessons have you learned?
It is extremely important to dedicate time to the preparation of the elements that will be displayed, to the pre-lighting and camera configurations. This is key to achieving perfect ‘on-camera’ XR, otherwise one must stick to the conventional green-screen setup if a lack of time necessitates post-production touch-ups.

Two years after the shoot of Vortex, technology has already advanced. Technical imperfections are or will soon be corrected by tool advancements, their adoption and the mastery of techniques by the artists.

New service providers have emerged, both in France and elsewhere, with various studio configurations, screens and hardware. This offers the opportunity for more choice based on rendering and production expectations. Moreover, an increasing number of production teams have gained experience.

But what should be emphasised above all is that the role of XR supervisor, a specialist at the same level as VFX supervisor, is an essential intermediary to interface with various department heads, a key component on this type of set, just like the first assistant director. In the know and vigilant about all technical solutions, they are the one person capable of understanding, arbitrating and defining the possibilities offered by all configurations. This XR supervisor must be chosen by the studios responsible for the production content, to truly become an integral part of the ‘VFX on set’ team in tandem with their post-production counterpart.

How do you see VFX in television evolving? Is the work becoming more frequent and increasingly technical?
We are on an upswing. Television, just like streaming platforms, is opening the door wide to the return of genre films to stand out from the classic or mainstream productions.

A new generation of broadcasters, producers and directors is unafraid to think about visual effects without constraints; special effects have become more democratised and accessible than ever before. Scripts are increasingly seeking input from VFX, not only for their traditional post-production work but also to produce on-set content.

tagged in: Cédric Herbet, Fix Studio, France 2, France Télévisions, Quad Drama, Vortex