Concept Overdrive Discusses Role in Avatar Special Effects

By Craig Taylor

January 4, 2010

James Cameron's 3D computer graphic adventure Avatar broke box office records during its first two weeks. With 750 million in sales worldwide, industry experts are calling the Avatar technology ensemble one of the greatest technological achievements of recent cinema history.

"We were approached by the Avatar production in late 2005, because we had been developing real time motion management systems," said Concept Overdrive President Steve Rosenbluth. "The Avatar workflow was all about integrating streams of motion in the production environment, both real and virtual, so our technology was a perfect match.” Concept Overdrive had an extensive role on the film’s special effects.

During Avatar’s production, six Overdrive motion management systems were used. Concept Overdrive technology was also integrated into Virtual Camera and Camera Wheels applications.

The "Samson" helicopter and Avatar’s biomechanical “Amp-suit”  were filmed on hydraulic motion bases controlled live by the Overdrive control system. Actors and camera operators performed inside the helicopter while outside operators simulated a flight path with joysticks. The helicopter motion was captured so the moves could be matched in the 3D computer graphic environments.

Using Simulcam technology, production crew combined real world actors and sets with computer graphics actors and sets, giving the director the experience of shooting the scene live. This allowed the shot to be framed accurately. The camera motion in Simulcam, both lens data and gross positioning from an optical motion capture system, streamed through an Overdrive system.

The Virtual Camera and its Concept Overdrive microcontroller handled analog and digital inputs, which were sent through an Overdrive system as well, to be streamed into the 3D computer graphics world. A camera-wheels device was also developed with an internal embedded Overdrive computer—this was fed into the CG world and used for tracking shots with frame-accurate sync.

Nearly every CG shot of Avatar flowed through Overdrive computers and protocols at some point. "Being a deterministic real time system, the Overdrive boxes were the only computers on set that could gen-lock (synchronize two sources together) to camera shutter and time code," said Rosenbluth. "On some shots there were four of our systems running in parallel, it was awesome to see it all happening. On-set users had no idea of how much data was flying around the room, they just took for granted that they could get the shot, which is how it should be."

Concept Overdrive noted that because of the technology utilized on Avatar, it saved years of labor and made the virtual production run like a live-action shoot.