Behind the scenes: Rebuilding Notre Dame

When historic Notre Dame cathedral caught fire a regular VR documentary took on new life, using innovative ideas and techniques to allow audiences to explore the space, see the damage and understand the building’s historic importance for themselves.

Only weeks after director Chloé Rochereuil and producer Victor Agulhon had wrapped shooting a ‘behind the scenes’ VR production in Notre Dame the cathedral caught fire. Rather than putting the work on the shelf they pivoted to a new plan and created the stunning ‘Rebuilding Notre Dame.’ We caught up with them to find out more.

How did this project come to be?

The story of how ‘Rebuilding Notre Dame’ came to life is a story of chance. It started as a totally different project. Back in January 2019 we were working on a VR documentary on the behind the scenes of the cathedral. At that time thousands of people were touring the cathedral each day. Our ambition was to open the monument to the public in VR through the story of Patrick Chauvet, the rector of the cathedral.

A few weeks after we finished this production, in April 2019, the cathedral caught fire. We realized that our footage of the cathedral was a treasure trove. The following week we listed all the material we had: footage, interviews, ambient sound – we had so much beautiful material that we felt we had a responsibility to make a meaningful use of it for the public. This is why we decided to produce a new documentary centered around the fire, as a tribute to Notre Dame.

Why did you feel this was a project that needed to be told in immersive media?

As VR creators, we believe that VR is infinitely better than other media for certain kinds of content, in particular accessing places closed to the public, and for creating a personal connection with people. A documentary about the Notre Dame fire really ticked all the boxes that we use to evaluate the VR compatibility of a documentary:

• A highly visual location. Notre Dame is a stunning place, its architecture and the details of the artworks are spectacular
• Exclusive access. After the fire Notre Dame has been closed to all but a handful of people, so allowing VR users to see for themselves was a unique opportunity)
• Personal encounters with people. The documentary offers direct access into the offices of the Mayor of Paris and of the Rector of the cathedral. You hear their stories as if they’re confessing to you

All of these elements combined with the powerful narrative of the Notre Dame fire make VR the perfect media. It allows the viewer to explore the cathedral, something that will not be possible to do in person for years to come. It’s a virtual door to the cathedral’s past & present. Only VR allows a sense of presence as strong as to re-create the emotions, the sensation that visitors had when visiting Notre Dame.

What prep did you do that you felt really paid off on this project? Storyboards? Previs? Shot list? What is your process?

Creating a 16 minute-long VR documentary did require a lot of planning. One of the challenges was that the documentary is centered around one monument. Storyboarding the whole piece was key to managing the progressive discovery of Notre Dame for the viewer; making every shot reveal something new and bring new information required careful planning.

One of the defining elements of this production was the uncertainty about being able to access the cathedral after the fire. Notre Dame is currently among the most restricted areas in France for two reasons: the risk of collapse, and the lead pollution caused by the fire. Gaining access, especially for a VR project, was a very long and arduous task.

As we needed to make progress despite the uncertainty, we maintained two versions of the storyboard: one that integrated footage inside the cathedral and one that didn’t. We were ready in the eventuality of not getting inside, so we were able to advance production while working to gain access.

In nonfiction VR we think that planning and storyboarding shouldn’t disrupt the natural action. We want to leave room for the unexpected; we want to capture the natural course of action, not a staged re-enactment. For us, making VR documentaries is about documenting above all.

For instance, when we filmed the mass celebration in Notre Dame before the fire, we asked for the timeline of the celebration. We had a rough sense of the visual we wanted, but the specific scene got defined in the moment as it unfolded. We adapt what we record to what people do, not the other way around. This is how interviewees forget about the camera, how we capture their emotions. We believe that, this is how you create a personal connection with someone in VR.

What were some challenges you faced in production and how did you solve them?

All in all, the production required approximately 15 days of filming. There are four interviews, lots of sequences outside, rooftop shots, drone shots and more. There is also a lot of footage that we prepared in case we couldn’t enter the cathedral that didn’t end up in the documentary, including workshops and outer views of the cathedral. The best ratio of filmed to used is definitely inside Notre Dame after the fire; we spent only half a day inside but ended up using approximately 5 minutes of footage.

The most challenging part of this production was gaining access to Notre Dame, but we solved it by engaging officials with our documentary. VR isn’t on the radar for many people; it remains a peripheral media. When access is as restricted as it became for Notre Dame VR isn’t a priority to communication teams; they will prioritize mass media such as TV.

In order to become a priority to them, midway in the production, we decided to double down on our efforts. We decided to involve more interviewees and extend the duration of the film. It was a way to include more diversity in the narrative, but also a way to engage influential leaders. As we showed them early cuts in headsets, they loved it to the point that they wanted to be a part of it, which paved the way for us to enter the cathedral.

Once we got access to the cathedral granted, we planned every single minute we would have inside. We knew exactly what shots we needed and how we would get them. There were three key elements:

• Using a rover. Due to the risk of collapsing, the area under the nave has been totally closed to people since the fire. These are exactly the places where you want to be as a VR user; it’s central & aligned. To get these shots we brought a remote control dolly system that would allow us to reach those places and get these beautiful perspectives, right under the holes.
• Camera placement. Showing the cathedral before and after the fire at the exact same location was the end-game, a dramatic way to observe the damage. Each shot required that we place the camera at the same location and height as the original shots to match the perspectives captured before the fire. This allowed us to overlay the shots perfectly and create the magical effect of bringing the cathedral to life in the outro of the documentary.

Drone shots. Since most of the damage is located in the upper part of the cathedral, aerial imagery came as an obvious solution to offer a plunging view on the hole left by the spire collapsing. It also puts the monument in perspective with the Paris skyline. Flying a drone in a busy city-center, on a sensitive construction site and under overlapping authorities offered its constraints, but gave us enough room to make the beautiful shots we needed.

What camera(s) did you choose for this project and why?

Camera-wise, we really took some advice from Eric Cheng, a producer at Oculus. His guidance was very clear; “go for the best content possible.” For us, that meant filming with an Insta360 Titan in stereoscopic 8K 10-bit as much as we could. The ratio of quality to convenience is great.

When flexibility was required such as with the drone shots we used lighter stereoscopic cameras. In productions such as this one, where the filming environment is very constrained, remaining flexible on hardware is central.

What was the most exciting part of the production?

The peak of the production was when we got back inside Notre Dame after the fire. After eight months of uncertainty and intense discussions with the cathedral team, stepping inside was really a magical moment. It was so peculiar: it seemed so familiar and so different. The busy and dark cathedral was now completely silent and wide open to the sky. The candles were still there and burnt wood was piled on the sides; it felt as if time had stopped.

We worked to convey a very particular feeling in the documentary, the feeling of suspension. During the four hours we spent inside we felt immensely privileged to be there, and we had a sense of responsibility to share what we were seeing to the public through VR. We knew that it was exceptional.

Working on a topic that catalyzes the attention of a nation provides lots of great moments. Interviewing the Mayor of Paris and introducing her to VR was memorable, and climbing on Paris rooftops with firemen to have a perfect viewpoint on the cathedral was quite a journey too. Contributing to building a historic memory for your city, your country and for the world is rewarding.

Can you give us an insight into your post workflow: the software you used, the mastering format and the editing process. What worked well? What were some challenges that you either solved or learned from?

In terms of post-production, we are a team of four editors and VR post-producers. Having a workflow that allows us to split the work dynamically is essential. Saving data safely is also critical, hence we do apply very conservatively the 3-2-1 backup rule. (Create one primary backup and two copies of all data, save backups to two different types of media, and keep at least one backup file offsite.)

The post-production process took a total of four months of full-time work. We used Mistika for stitching, Premiere for editing, and After Effects for masking, FX and compositing.

One tool that we used extensively for reviews was Frame.io. It allowed us to comment precisely on cuts and pinpoint at changes. It’s proven a very key element to iterate on edits. We also organized weekly group review sessions; the team gathered in VR headsets to discuss the overall comfort, the quality of the stereoscopy, and the precision of the masking on each shot.

Did you have to fix something in post? What was it?

We want the attention to be focused on the subject, not on the process. In ‘Rebuilding Notre Dame’ we removed all visible equipment that wasn’t part of the story; the tripods, microphones, and of course the teams during the interviews. Removing these things enhances the narrative without altering the reality it contributes to building a great experience. It was especially important for heavy machinery such as the rover and the drone. To remove the rover we reconstructed tile by tile the Notre Dame floor that was underneath the rover trajectory and we tracked it as it moved forward.

DRONE

We used multipass for the interviews. This combines two different moments of the same scene in a 360° shot. That allowed us to remain behind the camera with the interviewee during the production while giving us an easy way to be removed in post-production.

GEORGELIN

The shots on the balconies of Notre Dame were especially tricky in terms of stereo; although we optimized the camera positions during the production we’re still limited by the laws of physics. The 12th-century balconies offered very limited space and virtually no leeway to place the camera. Hence, the camera ended up very close to the barriers on one side and to the walls on the other side. In stereoscopy, these shots required extensive disparity work, masking and fine-stitching to land to a comfortable place.

Finally, we worked on giving a clear understanding of the two states of the cathedral, before and after the fire, through color grading. We wanted the look and feel of these scenes to be very distinct. We highlighted color features to create the appropriate atmosphere. Before the fire, we focused on the beige limestone and the intimate candle-like lighting inside the cathedral to create a warm orange color grading, reinforcing a sense of welcome. After the fire, we enhanced the tones of the light from the overcast sky and the dust and ashes from the fire, giving it a grey washed-out look. These aspects really contribute to making viewers instinctively perceive the difference between the two states.

How did you accomplish mixing Notre Dame’s before and after?

In any VR documentary, the post-production has to serve the narrative. In ‘Rebuilding Notre Dame’ we decided to have the beauty of the cathedral speak for itself, limiting extras to the bare minimum. The whole documentary builds up with very little effects until we reach the before/after shots during the mass celebration. There, we blended shots of the cathedral at the exact same location before and after the fire through slow fades.

For this effect to be powerful, it required that viewers were familiar with the two visual states of the cathedral. This is a moment when the cathedral magically feels revived before our eyes. It offers a vivid contrast between the beauty of the cathedral before and the damage caused by the fire.

BEFORE/AFTER

Since the documentary has been published we’ve received lots of messages from people who loved the piece, thanking us for the work and telling us how emotional it was for them. For many people it was their first detailed look at Notre Dame after the fire.

As VR creators, our goal is to offer Rebuilding Notre Dame to the widest VR audience possible in the best conditions possible. This piece was designed as true ‘VR first,’ so we focused on in-headset distribution. Working with Oculus was absolutely central to that. In terms of platform, Oculus TV is a powerful hub to host and promote a documentary. The Media Studio team really does a wonderful job of providing creators with the tools we need to promote narrative experiences inside & outside of VR. Finally, in terms of hardware, I can’t think of any devices that are more popular among consumers than those from Oculus.

Step inside Notre Dame – again or for the first time – with Rebuilding Notre Dame in Oculus TV on Oculus Quest.