Motion capture—a technique used to capture 3-D data that represents a live performance in order to generate realistic movement—has garnered much attention this month, thanks to Robert Zemeckis’ The Polar Express. Zemeckis and Sony Pictures Imageworks, Culver City, Calif., captured the performances of live actors who wore special sensors attached to their faces and bodies. The computer took that information, then digital artists applied it to the CG characters in the film to give them the movement of the live actors.
Motion capture was also the basis of "Transformer," a currently airing U.K. commercial for the Citroen C4 automobile via Euro RSCG London. The spot begins with a shot of the automobile, which transforms itself into a robot (all parts of the robot being car parts, such as doors and windows) and performs a dance before returning to the form of the car. The ad was directed and edited by Neill Blomkamp of Toronto-based Spy Films, and features visual effects from The Embassy Visual Effects, Vancouver, B.C.
The background was created with high-res digital photos that were converted to 3-D space, and the foreground elements, including the Citroen, were modeled and rendered in 3-D.
The creation of the dancing car/robot began with a motion-capture shoot at Santa Monica-based Blur Studio, deploying the talent of choreographer Marty Kudelka, who works with the likes of pop singer Justin Timberlake. The team used Blur’s Vicon motion capture system to acquire the performance data.
The car itself was scanned by Paris’ Gentle Giant and then cleaned up by Viewpoint Digital, Orem, Utah. The Embassy cleaned up the scanned data, adding details back into the model, extending the detail to include a fully articulated robot, applying motion capture data and then rendering and compositing the elements.
"The biggest challenge was getting the motion data to carry over into an inorganic object—without the flexibility of organic joints," Blomkamp explained. "We had certain limitations. We had to be sure that [auto] parts didn’t crash into other parts of the car during the dance. And [the character] couldn’t get too low to the ground, as a car would not be able to do that."
Motion capture, he said, was the only option "if the goal is pure realism. It doesn’t matter how good an animator is, you will never get [the movement] you get with mocap. … If you are doing a walking robot, you would hand animate, but we wanted a performance, and mocap is great for that."
"I think motion capture probably will become more common," he added, "[as] CG characters are going to become more abundant."
A key to the effects work was the use of the Modo, a new subdivision surface and polygonal modeling platform. Developed by Luxology, San Mateo, Calif., the software combines a real-time subdivision surface-modeling engine with a user-centric, customizable interface that includes hundreds of production-oriented tools. As well, Modo is designed for smooth insertion into existing 3-D pipelines. The Luxology team comes from the industry and develops its technology with heavy input from working digital artists-including Paul Davies, who served as lead modeler on the Citroen commercial.
"One of the big battles in 3-D is getting to a comfort level with the tools," Davies said. "Modo is new, but once you learn what it has that is different, it’s easy to incorporate it into your workflow. … I spend more time on [creative] issues than on how I’m going to address the issues."
"Modo was up and running in a day," reported Embassy founder Winston Helgason. "Modo really helped with edge controls—a really clean edge can be hard to get. And what’s also nice in the modeler is reflection features, so we can see how light plays across a surface and the reflections."
NewTek’s LightWave 3D was also used on the 3-D work for tasks including rendering; compositing was handled in Apple’s Shake.
