OUT OF SYNC.(use of computer graphics for the crash scenes in the race-car film Driven)(Technology Information)

A digital car crash blends real-time and slow-motion effects

It's not unusual for victims of violent car crashes to report having experienced the event in slow motion, as if they had been propelled into another dimension where seconds passed like minutes. Just such an experience unfolds vividly and dramatically in the opening crash scene in the race-car film Driven.

"Director Renny Harlin's vision for the scene was to show the audience what a driver sees and feels during a crash," says Ray McIntyre Ir., visual-effects supervisor at Pixel Magic (Toluca Lake, CA), which created the digital effects for the scene. "We did this by mixing real-time and slow-motion effects. Everything occurring around the crash--such as the other cars moving on the track--is in real time, but the entire accident itself unfolds in slow motion. When Renny explained his idea, we thought it might look odd, but once we did it, we knew it was a brilliant idea."

Pixel Magic created 50 digital-effects shots for the movie, nearly all of which are for the mixed-motion collision and a similar crash that appears later in the film. Other studios also contributed effects that are dispersed throughout the film, mostly involving background elements. In Pixel Magic's blended-time sequence, the character Memo Moreno brushes wheels with another racer. At 150 mph in the open-wheeled race car he is driving, it's enough to send his car skidding into a guardrail, then flying back above the racetrack as debris from the impact scatters in all directions. At the precise moment the car lands, another car strikes it, and the impact catapults it back into the air, before it cartwheels off the track and into the grassy infield.

"It would have been impossible to create this chaotic, yet strangely poetic, scene without using computer graphics," says McIntyre. "It's impossible to have one element in slow motion and the rest in real time. Also, you could never choreograph the accident to occur precisely as you'd like, even by rigging it [with pulleys]. And you'd never put the drivers in such a dangerous situation."

Poetic Motion

According to Brian Jennings, Driven's visual-effects supervisor, when he and director Renny Harlin came up with the concept of the crash, he knew part of the scene could be accomplished practically, but not all of it. First, they shot live footage at a test track in Montreal. For the beginning of the sequence, the crew filmed two professional drivers as they bumped wheels. For the next shot, they rigged a full-size replica of the race car to a pulley and wire system, and slammed it into the guardrail at 70 mph. "We had to digitally remove the big cranes, rigs, wires, and other equipment from the shot, leaving only the car on the track," says McIntyre. This was done using Pinnacle Systems' Commotion software. The effects artists also created computer-generated cars that were inserted into the background. "We tracked the scene using RealViz's MatchMover and added digital rain and mist, because the crash was supposed to occur during a downpour."