Apr 20, 2016

Ghost Cell" depicts a new side of Paris with cutting-edge CG technology.

The city of Paris may be one of the most photographed and filmed cities in the world. But you've probably never seen Paris like this.

Director and CG artist Antoine Delacharlery's "Ghost Cell" uses point cloud and wire frame images to recreate daily life in the French capital in almost microscopic, but somewhat imperfect detail The film is a work of art. Indeed, the tagline for this six-minute short is "an organic plunge into the organs of Paris, seen as cells through a virtual microscope."

The idea of seeing Paris from such vastly different perspectives came from two places. First, Delacharelli had observed that 3D scans generated by LIDAR (laser scanning) and photogrammetry (combining several single photographs to create an accurate 3D model) had become part of architecture and film production. The use of 3D scans in those fields was, of course, for measurement purposes, but the director thought that the resulting images had a mysterious, ghostly quality.

The other story that director Delacharelli wanted to tell about Paris was the story of "the expanse of life," he said. The film, he explained to Cartoon Brew, "speaks to the expanse of life and the similarities between human structures and the patterns of nature." 'In fact, there have been scientific studies comparing the growth of mushrooms to the routes of urban roads, and it was the exact same pattern.' [Godfrey Reggio's 1982 experimental film Koyaanisqatsi included slow-motion and time-lapse footage of cities and landscapes across the United States. 'I was always on the RER, the ring train in Paris. So I wanted to talk about commuting ("migration pendulaire" in French). I thought it would be a good idea to compare human flows with micro swarms of life."

To put these inspirations together into a short film, Delacharelli began experimenting with several 3D scanning technologies. He said, "At first we tried Microsoft's Kinect, but then we ended up using only photogrammetry, primarily Autodesk's 123D Catch. Photogrammetry was the best technology here for multiple reasons. I could just use the camera, I could scan really large structures, and I could get great textures. For the final look, I looked to find something nice out of the bugs that came out of these techniques."

At various locations in Paris, Delacharelli scanned buildings, people, and other scenes; the number of photographs that make up a single scan can range from 20 to 60. The resulting 3D scene may have been derived from a single scan, or it may have been a mix of multiple scans, finished geometry, wireframes, and the "buggy" look the director was looking for. Some scenes had geometry reaching 6 million polygons.

Then came the animation production. Using Autodesk's 3ds Max, Delacharelli and a small team did the 3D scanning and added subtle, sometimes more than subtle, movement to the action. All of the 3D scanned models were real, which was really interesting to me," he said. It was about finding ways to show the organic qualities of high-tech 3D capture."

"Ghost Cell" has a stereoscopic version that can be viewed with anaglyph glasses (glasses with red and blue lenses) for a more immersive experience. Says Delacharelli, "I think the stereoscopic version works well with the wireframe aspect and transparency aspect of the film."

There are also slight hints of color in places in the mostly black-and-white short. The director calls this the "secret color" of the film. He says, "We used a lot of 3D scanned textures so we could use all the colors. Using color really changes the picture. In fact, I was amazed at the level of detail in the scans, even with just one camera. The textures made it even more realistic. "

Delacharry, who has used LIDAR-like imagery in recent music videos and animation projects, has some surprising observations about where this technology might reappear. "Google's self-driving robot cars incorporate multiple cameras for 3D visualization, and I like the fact that '3D scan vision' is the way the car's computer 'sees' the world around it."

"Ghost Cell" was produced by the French production company Autour de Minuit and has been shown at several film festivals and won the Audience Award at the Clermont-Ferrand International Short Film Festival Delacharlery's work can be seen on his website and YouTube channel Delacharlery's films can be seen on his website and YouTube channel.

"Ghost Cell" Main Credits Director Antoine Delacharlery Producer Nicolas Chmelkin Screenplay Antoine Delacharlerie Music: Bastien Prévost Editing Antoine Delacharlery