Step by Step: 300
When Director Zack Snyder took on Warner Bros.' movie version of the graphic novel 300, he used wall-to-wall visual effects to create the film equivalent of the Dark Horse Comics tale by Sin City author Frank Miller. There's a certain irony in using modern digital tools to depict a Greek battle that occurred in 480 B.C., when 300 Spartan soldiers took a famous last stand against Persian invaders. To create these multitudes of effects, Snyder enlisted a phalanx of studios, including Australia's Oscar-winning Animal Logic.
“The entire film was shot on soundstages against bluescreen,” says Kirsty Millar, visual effects supervisor at Animal Logic. “We had 176 shots with about eight minutes of screen time, including a 70-second tracking shot.” That shot was filmed at 150fps simultaneously by three cameras on a single head, including wide, medium, and macro lenses. The challenge for Millar's team was to use this footage to create a nested zoom, producing a dramatic perspective shift within a single shot. “We had a huge amount of footage to shrink into 1,700 frames,” Millar says.
Editorial provided Animal Logic with an animatic to use as a template. “I think they put it together in Avid Elastic Reality,” Millar says. This guided Animal Logic as it broke apart the three camera views and worked out the timings, which had to be exact. “There were lots of speedups and slowdowns, and they had to be motion-interpolated to get them smooth. Even that wasn't close enough to the actual frame that they had in editorial, so we keyframed the motion interpolation.”
Animal Logic used Apple Shake to handle all the compositing tasks for 300 and used 2d3 Boujou software to track the camera work. “From the wide-angle camera track, we worked out the offsets for the close and mid angles,” Millar says. “We didn't render out the wide, mid, and close angles. We just tracked the wide, worked out the offsets for the mid and close, and rendered those out.”
This tracking information enabled Animal Logic CG and matte painting artists to create a background environment that moved in correct perspective throughout the nested zoom. The background for the scene was a rock face, which was built in 3D geometry using Autodesk Maya. The surface textures were painted in Adobe Photoshop and then mapped onto the geometry. “When we rendered the environment [using Pixar RenderMan], we rendered it with the zoom in it,” Millar says.
Because 300 is based on a graphic novel, the director wanted a stylized look. “Making real rocks is easy because you can look at reference photography,” Millar says. “When it's not supposed to look real, it's difficult. You tread a fine line between something looking stylized and looking like Star Trek circa 1980.”
The animatic from editorial provided few clues. “It just had a low-res background panorama with a 2D zoom in and out. It gave us a bit of a color palette, but that was pretty much it,” Millar says. “We were dressing the environment to camera on a shot-by-shot basis, so it wasn't a ‘one size fits all’ environment solution. For this long tracking shot, projecting a matte painting onto geometry was perfect. We used a piece of software that we developed for Happy Feet called Camper, which aids in texture projection. It takes any guesswork out of where you're going to need textures projected.”
Significant rotoscoping also was needed to remove traces of physical sets before replacing them with CG. “Joining the live action ground to the 3D ground meant that we had to get a soft line to blend it, so we needed to rotoscope along the entire edge. It's a necessary evil,” Millar says. “But it's character building.”
Once the 3D rock background was in place, Millar's team determined how far it would be from the battle action, and how many digital doubles would be needed to flesh out the scene. “The live actors are about one-quarter frame, and everybody beyond them are digital doubles,” Millar says. 3D-CG Lead Andrew Jackson gathered sword-fighting information by taking his animators to a parking lot, putting tracking markers on them, and photographing them with DV camcorders. “They had capes, swords, shields, and helmets, so they could get in character,” Millar says. “We got triangulated footage that we took into Maya and pretty much did 3D rotoscoping on top of it in order to get our animation cycles.”
Several digital additions completed the illusion, including simulated cloth capes created with SyFlex software. Millar's team also added CG spear tips, and even replaced one actor's arm with a Maya-animated version to make his spear-throwing appear more powerful.
Blood was everywhere. “We had some live-action blood squibs, but we needed much more,” Millar says. “We used high-speed blood elements from our library, plus we generated some 2D particles and 3D fluid blood.”
Swirling dust and debris were needed as well, and these were Maya sprites and particles. “Because the director wanted a layered, graphic look, we rendered foreground, mid, and background layers and then took them into 3D to force some depth of field,” Millar says.
The final touch was dramatic color grading. “The lighting was very diffuse, which made the helmets and shields look plastic,” Millar says. “We did selective grading to make them look like metal. For the Spartans' capes, we keyed the red out separately, did our overall grade, and then keyed the reds back in so that color wasn't lost. We generally set our grade with a lot of dynamic range, so they'd have something to play with in the DI.” Millar, who previously worked on the stylized Moulin Rouge, says, “Making graphic filmmaking look atmospheric is always very challenging. We've never done a shot like this before.”
Director: Zack Snyder
Director of Photography: Larry Fong
Visual Effects Supervisor: Chris Watts
Visual Effects Art Director: Grant Freckelton
VFX Supervisor: Kirsty Millar
3D Lead: Andrew Jackson
2D Lead: Dave Dally
Lead Compositor: Tony Cole
3D Artists: Jonathan Dearing, Clinton Downs, David Hansen, David Hyde, Nigel Waddington
2D Artists: Lindsay Adams, Vaughn Arnup
Art Department: Nicole Mather, Evan Shipard