To handle the destruction work, MPC's software and vfx teams in Vancouver developed a new destruction system called "Kali" based on Pixelux's DMM, a finite elements solver usually used in the video game industry. This new approach allowed materials to flex and bend before breaking and the ability to define physical properties to realistically simulate wood, metal and stone breaking. It also gave the modelers the freedom to create assets without worrying about how they would break, eliminating the time consuming process of pre-cutting the geometry. MPC then implemented a full retiming solution into the pipeline, allowing artists to work on everything at 100fps and apply the final retime at render time to get accurate motion blur and animation interpolation. The compositing team then pieced together hundreds of CG layers for each shot.

Then, for the World War I sequence, in which Babydoll and her fellow inmates battle German storm troopers with steampowered mechanical faces on the battlefield and in the air, climaxing with the destruction of a giant Zeppelin, Pixomondo (under the supervision of Rainer Gombos) built and destroyed all aircraft, including a Meka, a futuristic armored endoskeleton. They used 3ds Max, Vray, Photoshop, Synthese, Nuke, FX Fume, Afterburner, Krakator, Thinking Particles and proprietary software.

"There were many meetings where Zack and Damon and I were talking Heavy Metal," DesJardin recalls, "and how that magazine, in particular, is responsible for a lot of us fanboys just thinking of these hybrid sci-fi/fantasy stories and environments: 'I want to have a WWI sequence where the girls go in and kick German ass. What if I have some zombies? Cool!'

"We knew Pixomondo's work from The Red Baron, so we figured they would be ideal at building the World War I environment and assets. The only thing we did was give them a face lift to give the scene a sci-fi, steampunk vibe. But Pixomondo made the giant Zeppelin. Rainer really tricked that thing out: there's detail that I never even dreamed of. He even pushed the steampunk guys that I asked for out on the strut near the engine to the nth degree."

For the Dragon sequence, Animal Logic (supervised by Andy Brown) designed and built the entire volcanic environment and a medieval castle. In order to establish the battle between knights and orcs, they used a combination of motion capture, Massive software and hero animation in Softimage. A proprietary tool was written for viewing and animating Massive crowds in Maya that added speed and efficiency. The dragon fire was created using the proprietary "Snap," developed on Snyder's Legend of the Guardians, but on a much larger scale for Sucker Punch. The R&D department also wrote a custom hair sim tool called "Alfro," for its first foray into digital doubles with long hair, when Babydoll hangs suspended from the dragon.

In fact, the dragon was inspired by Dragonslayer, per DesJardin's suggestion."Zack actually liked one of the Harry Potter dragons and we looked at that first," DesJardin explains. "We fine tuned it to make it more like Dragonslayer: immense wings for cool flight, the neck is shorter but the spikes come off the face the same way. We also studied the motion blur that Phil Tippett achieved with his Go-Motion technique. We took that and ran with it because we knew we had to do the flight attack with the airplane."

Bill Desowitz is senior editor of AWN & VFXWorld.