Directors Joseph Kahn (Torque) and Rob Cohen (The Fast and the Furious,
Stealth) teamed with VFX house Digital Domain
(Venice, CA) to deliver effects-heavy spots for Saab that capitalize on
the car-maker’s background in aviation engineering.
With the tagline "Born from Jets," Kahn’s:30 "Transformer" depicts a
fighter plane that evolves into the Saab 9-7X. The challenge for
Digital Domain’s visual effects supervisor Eric Barba and Senior VP,
General Manager Ed Ulbrich was scaling the two objects to make the
transformation authentic.
"Joseph was very focused on keeping it real. He never wanted [the
metamorphosis] to feel like science fiction, or like it was defying the
laws of physics," says Ulbrich. "The overriding creative objective was
for it to be a plausible, mechanical, legitimate technology."
As the team got involved, however, they realized that the amount of
time it would take for a jet to fold in upon itself and transform into
the size and shape of an SUV would take minutes as opposed to the 20
seconds they could spare for the spot. "When we began the pre-vis we
realized,‘Oh God, this needs to happen a lot faster than we would want
it to be,’" recalls Ulbrich.
Speeding up the transformation was not an option entertained by the
crew. "Something the size and scale [of a jet] should move slower to
give a sense of its mass and weight," explains Ulbrich. "If it moves
fast, it feels kind of light and flimsy. So we had to do lots of
cheats. We used creative editing to lapse time and cheat the various
levels of progress. So while it feels like we’re cutting on action and
it’s all happening in real time, in fact, we’re skipping and using that
to our advantage."
Ulbrich is quick to point out that when both the plane and car are 100
percent digital, "pre-vis is everything." For "Transformers," pre-vis
determined the length of the shots, camera speed, framing and
composition. "It never ended. It just turned into animation once we had
background elements from location – both moving footage as well as
stills- it became the finished commercial."
Photogrammetry techniques allowed the team to re-create locations and environments in 3D, while photo-realism was achieved through rendering. “We have a software pipeline where we use multiple renderers, tools and techniques and then combine them downstream in compositing,” says Ulbrich. At the heart of the pipeline is Nuke, Digital Domain’s proprietary in-house compositing software. “Nuke allows us to render many different layers – you can render specular highlights, ray-traced reflections and refractions, radiosity, ambient occlusion passes and fresnel passes ‘ but then in the compositor, we can dial in the relative ratios and balances between all of those layers until it looks photo-real.”
For “Transformers” the team largely used the Lightwave renderer, but Ulbrich says the spot really came down to gathering all the various bits and pieces and choosing how to put them together ‘ this was partly achieved through the painstaking process of sampling the environment – in the case of “Transformers,” the airplane hanger that Kahn chose to shoot and Digital Domain had to replicate.
“We shoot HDR (high dynamic range images) to get a photographic representation of the lighting in the environment and we use that as the basis for our render, so we’re lighting our CG models with the same exact lighting that was on location.” Shooting HDR also provided Digital Domain with reflection maps and allowed the crew to derive 3D geometry to raytrace the environment into the shine of the jet and the SUV.
“We also modify,” says Ulbrich. “If you look at the two commercials side by side, the jets don’t match. Anatomically they’re exactly the same, but we went with a more matte-military looking jet for Rob Cohen’s “Delta” [the spot depicts five fighter jets falling into formation behind the new Saab Aero convertible which leads the way across the Utah salt flats] and we chose a black, lacquered jet in ‘Transformers.’ This was done purely for art direction reasons.”