The Chauvet Cave has been granted World Heritage status, and since 2015 has been receiving support as part of EDF's scientific skills sponsorship initiative. Virtual reality experts from EDF's R&D department have repurposed computer software developed for the company's needs in order to gauge how visible the cave paintings on the walls were using simulation.
An outstanding world heritage site

The Chauvet Cave is near Vallon-Pont-d'Arc – in France’s Auvergne-Rhône-Alpes region – and was granted World Heritage status by UNESCO in June 2014.
It was discovered in 1994 and harbours a unique heritage of universal value: it contains the oldest cave paintings ever found (made some 36,000 years ago). That makes them some 18,000 years older than the ones discovered in Lascaux. As well as being extremely old, what sets the Chauvet Cave apart from others is the extremely beautiful drawings and engravings on its walls and the sheer diversity of the animals depicted (more than 14 different types of animal, including lions, rhinoceroses, bears, mammoths, other felines and elks).

“When EDF Group Foundation commits to sponsoring a scientific project, the company's expertise needs to be able to assist with a particular scientific challenge posed by the partners, and the solution found needs to be completely original – and that is the case with the Chauvet Cave".
Guillaume Thibault, research engineer with EDF's R&D department.

The oldest art gallery in the world – a treasure trove for archaeologists

Since it was discovered, the Chauvet Cave has been the focus of a conservation programme. And since 1998, it has been part of a research programme, meaning that only scientists have access to this fragile heritage site. Indeed, the works of art produced by our distant ancestors have been protected in an extremely stable geological environment: since its entrance was closed to the outside world, the Cave's contents have been remarkably well preserved. So when these natural vaults were opened up, the cave painting treasures inside them were immediately exposed to natural and human stresses, and so in danger of being damaged.
To protect the unique testimony of the Chauvet Cave, which is now sealed off to the general public, a synthetic physical replica – "Chauvet 2" – was opened in April 2015. The 3D digital model was produced using research conducted by France’s Ministry of Culture and the CNRS (centre for scientific research).

A question: who saw what and from where?

The works painted in the cave's darkness are fascinating for their beauty and just how modern the lines that make them up are. Archaeologists have asked themselves numerous questions about them, such as: What were they supposed to mean? Who were they for? Are they ritualistic representations or simply artistic drawings made for the sake of it? Were they all created as part of a whole? Based on their position and how visible they are, were they for groups or for solitary observers?

"We had no idea how an observer from that era really saw them. All they had to light their way was an oil lamp or a torch. Or perhaps they could make a fire on the ground", said Jean-Michel Geneste, the archaeologists who led the Chauvet Cave's scientific team until 2018.
These questions had been raised, but obviously the archaeologists had no means of conducting tests in the Cave. The idea of creating a digital simulation was considered, but again, they had no scientific means to simulate the levels of visibility. Two of EDF's R&D researchers with specialist expertise in this area were able to help with this key issue. Thanks to them, prehistorians now have a reliable digital simulation which means they can answer the question "who saw what and where?”.


 The Chauvet 2 Cave - Fabre Speller- Architects - Workshop 3A - F.-Neau - Stage - Sycpa -Photo: Patrick Aventurier

The virtual reality expertise of EDF's R&D department comes into play:
To optimise maintenance operations as part of projects designed to extend the service lives of nuclear power stations, the R&D department's research engineers have built powerful tools for industrial purposes, leveraging the potential of virtual reality technologies in particular. The VVProPrépa programme, for example, provides operatives with virtual means for visually accessing facilities. This way, they can use digital technologies to prepare their operations. These are digital training methods, supported by the most up-to-date knowledge about the cognitive capacity of people placed in complex environments, and they have been made available for the TIPTOP project (for processing perceptual and topographical information applied to the cave paintings).

"We have used and improved two software components developed by the R&D department for nuclear facilities",  says Guillaume Thibault. I won't compare a nuclear power station directly to the Chauvet Cave, but they do have a few things in common. They are both complex environments: numerous obstacles reduce visibility (walls in nuclear power plants, and walls and their various recesses inside the caves), which is tackled by software component no. 1; moving around is difficult (equipment occupies a great deal of the ground space, and there are ceilings in nuclear power stations and stalagmites and stalactites or uneven slopes in caves, etc.), which is tackled by software component no. 2".

An experimental method and a multidisciplinary team

How is a cave painting seen in the darkness on a wall when I move towards it holding a torch with a flickering light? That was the initial question which resulted in algorithms developed by EDF's R&D department being applied to the paintings inside the Chauvet Cave. Guillaume Thibault and Jean-François Hullo developed an experimental calculation method factoring in visual perception while moving (based on the hypothesis according to which the Homo sapiens of the Chauvet Cave was doubtless more accustomed to the darkness, but had a level of visual acuity that was similar to our own).

Expertise combined with a multidisciplinary approach was needed to develop a method that could factor in a whole array of data: imagining a Homo sapiens of normal size, their motility and field of vision in a standing position or crouching down... and incorporate differences in perception based on the dimensions and the techniques used to create the cave paintings.

It took two years to collectively develop the analysis tools, tested on data gleaned from the 3D digital model of the Chauvet Cave. Real-life tests, led by Jacques Droulez, a CNRS specialist in cognitive sciences, were conducted, not in the cave itself, but in a quarry. Copies of the Cave's paintings were created by Gilles Tosello, an artist and researcher who worked on the Cave's replica.

The simulations resulted in the first visibility maps

 "We were able to obtain scientific results and find out what people saw and from where they saw it – something that had never been accomplished before with cave paintings. By the light of a torch or an oil lamp, we succeeded in working out how far away a person could see – either roughly or in detail – a rhinoceros drawn in black, in red, or engraved on a cave wall".

Guillaume Thibault, research engineer with EDF's R&D department.

The simulations reveal the areas from which a particular group of paintings might have been more or less visible, giving clues to how they may have been staged and sequenced. The results of the TIPTOP project were submitted to the Chauvet Cave's scientific team in March 2019. They are in the process of being published. A series of pictures, funded by EDF's Group Foundation, will serve as a means of illustrating the method used.

The project which began in January 2015 was conducted within the framework of an agreement between EDF Group Foundation, EDF Research and Development, the CNRS (Edytem/Chambéry and ISIR/Paris) and the Ministry of Culture.

Click on the links below to read the press pack articles:
•    Virtual Armchair technology at the Cluny Museum
•    The EDF Foundation’s scientific skills sponsorship initiative supporting civil society