Mac Guff Ligne created the vfx in the train sequence, which is the most outrageous stunt of Transporter 3. Frank drives his car through an overpass railing and lands on top of one of the fast-moving coaches. All images © Lionsgate Ent.

With the Transporter saga, producer Luc Besson has managed to make a point: French filmmakers can deliver the same adrenaline-fueled action sequences as Hollywood. The franchise follows the adventures of top notch driver-for-hire Frank, a man whose clients often prove to be less reliable than him...

Starting with the first movie (2002), car stunt coordinator Michel Julienne has kept on designing and shooting some of the most spectacular car chases of the past decade. In Transporter 3 (opening today from Lionsgate), he once again delivers the goods... with a subtle but crucial help from the visual effects team.

The film features more than 600 vfx shots, but audiences worldwide will be able to spot a few of them only. Two key vendors were hired to create them: Mac Guff Ligne (300 shots) and Duboi (250 shots), with Éclair Numerique providing additional vfx work. At Mac Guff Ligne, Visual Effects Supervisor and Co-Founder Rodolphe Chabrier assembled a team that included VFX Producer Jacques Bled, VFX Exec Producer Delphine Domer and CG Supervisors Marie-Claire Bazart and Antonin Seydoux.

The team was challenged by an almost impossibly tight deadline: eight mere weeks to create more than 300 shots with a team of 35 artists... "We mainly worked on the climactic train sequence," Chabrier says. "All the interiors were shot on stage. The carriage set was surrounded by a white cyclorama. It created an overexposed, washed out look that accurately reproduced the look that a film camera would obtain when shooting inside a train under those light conditions. This cost-efficient approach allowed director Olivier Megaton to get his shots directly in camera. When he felt that exterior views were required behind specific windows, we would add them in."

The train sequence features the most outrageous stunt of the whole movie. Upon seeing the bad guy escaping in a train, Frank drives his car through an overpass railing and lands right on top of one of the fast-moving coaches... This miraculous maneuver required a little bit of Mac Guff's magic to be successful. "We used a succession of different techniques to make it look real," Chabrier notes. "The sequence was extensively storyboarded, and we analyzed it shot by shot to figure out what the best approach was. First, we filmed with matching angles the car driving through the railing at a safe location, and the train on its tracks. The two plates were combined in compositing. All our tools at Mac Guff are proprietary. For the following shots, we filmed a real car driving on a carriage rooftop set. We also shot a static car that was attached to the real moving train. In some shots, we extracted it from the plate and did a 2D animation to have it move on the carriage. In other cases, though, we had to paint it out as the shots were ultimately used in another part of the sequence, when the car wasn't supposed to be there yet. We did lots of fixes of this kind, due to continuity issues..."

The car and actors were filmed on a soundstage, surrounded with a bluescreen and mounted on a rig. Duboi created a three-layer composite for each shot: the environment in the background, the car in the mid-ground, and reflections on the foreground.

When no practical means or 2D technique was deemed suitable for a specific shot, 3D animation was employed. "Audi provided us with CAO files of the car, which gave us a solid basis for the 3D model. We had to retouch it significantly though, as the Audi they used for the shoot was a newer model. We then matched the elaborate paintwork precisely -- no photographic texture maps were used. The paint had a very special sheen that proved difficult to match. Sometimes, it looked just like a mirror, which made our job all the more difficult! During principal photography, we shot HDRI images that allowed us to build spherical photographic environments in which we could light the CG car. It gave us very accurate reflections on the body. We had several versions of the vehicle, depending on how dirty and damaged it was in any specific scene. The car was mainly featured in the 'impossible' shots, when it is flying right at camera, or when it is seen jumping from one coach to the next."

The CG car was also used to add proper reflections on the real car. Since the vehicle and the train had been shot in separate locations and under different light conditions, the car body didn't reflect the environment in which the action was supposed to take place. In this case, the CG car was tracked to the real car, and the train plate reflections projected onto its body. The reflections were then composited on top of the real car. 3D animation was employed to fine-tune 2D composites as well. In one shot, the real car's trajectory didn't exactly match the train's path. The team extracted the car from the live action plate, projected it onto the CG version, and used the 3D model to correct the perspective.