Replacement Vehicles
Issue: Volume: 28 Issue: 1 (Jan 2005)

Replacement Vehicles

The commercial was, indeed, a true test for photoreal computer-generated graphics. The project required artists to replace the 2004 Cadillac DeVille live-action cars shot on location for the original commercial with a computer-generated replica of a CTS from Cadillac’s newly introduced 2005 line.

For the 2003 spot, titled “Magic,” RhinoFX brothers Ronen and Vico Sharabani altered the summertime film shoot by turning day into night, creating digital matte paintings, adding snow and lighting effects, and placing an entirely new night sky into the scene. To achieve this, the artists used Discreet’s Inferno compositing system, integrating elements such as snow and bells, which were created as separate objects in Alias’s Maya. The artists also spruced up the scene by removing unwanted objects, shrinking trees as to not obscure the audience’s view of the vehicles, and inserting CG models such as doorways, windows, and seasonal decorations.
Artists at RhinoFX created digital effects for a Cadillac commercial not once but twice. Last year, the group created a winter wonderland setting for the live-action spot. This year, the team replaced the real 2004 car with a CG version from the 2005 line

This year, Cadillac wanted to revisit “Magic,” but there was one problem: The commercial needed to feature new vehicle models for the coming year. In the past, this has meant reshooting the spot, but the folks at RhinoFX offered an-other, less-costly solution.

“We have had great success in creating CG cars,” says Camille Geier, RhinoFX senior executive producer. “So we explored the possibility of painting out the live-action cars and replacing them with a single vehicle that was entirely CG.”

To create the car virtually, the artists digitized individual pieces of an actual new Cadillac CTS. After the artists assembled the 3D parts, they created textures and built shaders in Maya 5 to simulate various surfaces-car-paint shaders, headlight refractions and reflections, tire rubber, hubcap chrome, and more. The artists then reopened “Magic,” and painted the cars out of four scenes to make space for the new model. So that the new car looked like it belonged in the shots, the group hand-tracked and animated it using Maya, matching the initial cars’ movements as well as those of the camera.

“What makes the car look real is its movements,” says CG director Natasha Saenko. “All the subtleties of a moving car were taken into consideration: how heavy the car is, how its suspension works, how fast it travels, how its wheels revolve, and how it tilts when it turns. This was even more challenging because we had a live-action reference car from the previous commercial that we had to match.”

Once this was done, the team studied the previous live film plates and then used Maya and Mental Images’ Mental Ray to light the car so it would perfectly match the partially synthetic environment.

“We knew that for the new car to fit into the scenes, it had to reflect them,” says Saenko. “So to achieve realistic lighting, we reconstructed the entire environment by creating large background panoramas and 3D buildings in Maya, through which the new car travels. This gave us realistic reflections and environment colors.” The artists also added subtle nuances like Christmas lights that turn on as the car passes by, which helped tie the vehicle into its background, as did the use of accurate shaders and global illumination.

Lastly, the group used Inferno to blend the CG car into the live-action plate. In some instances, the artists applied layers of atmosphere, snowflakes, glows, and shadows to the composite, to make it look even more believable.

According to Saenko, it was an unusual experience for the group to do major effects on a project not just once, but twice. “There is always a chance for something like this to look unnatural and overly processed,” she says. “But this experience solidifies my belief that technology has come a long way and that we have the tools that can make anything we can imagine into a reality.”
To ensure that the digital vehicle blended seamlessly into the live action, the artists tracked the CG model and animated it by hand in Maya, matching the movements of the original car and camera.

In the end, the spot looks seamless, without a hint of CGI. “If you think about what it would have taken to re-shoot those scenes, the value we brought to the table was enormous,” says RhinoFX partner Rick Wagonheim. “I’m not saying CG cars will ultimately replace real cars, but there are situations where CG makes more sense, whether it’s due to dollars, control, or feasibility. More and more, directors are recommending CG solutions. Its time has arrived.” -Karen Moltenbrey