International VFX house Pixomondo has created more than 270 VFX shots for Snow White and the Huntsman, the latest reimagining of the folk tale.
The film’s visual effects supervisors, Cedric Nicolas-Troyan and Phil Brennan, enlisted Pixomondo to work on much of the prologue, which features a barrage of fighting, as well as the final siege sequence.
Pixomondo VFX supervisor Bryan Hirota, along with digital effects supervisor Andrew Roberts, matte painting supervisor Matt Lee and compositing supervisor Randy Brown, oversaw the project for the company.
With concept artwork and a rough teaser created by Nicolas-Troyan for guidance, Pixomondo began working on shots in August 2011. In the prologue battle, an army of evil shadow soldiers marches against the valiant king. When the shadow soldiers are struck, they fracture into shards of obsidian glass, with additional shatters radiating outward. To achieve the effect, practical soldiers were first shot in the battle sequences for realistic interaction and then replaced with CG versions before the affected knights splinter.
“The CG duplication work done by Pixomondo was so flawless, there were several times when Cedric and I had to reference the original plates to determine which actors were practical and which were CG,” says Phil Brenna. “Even more impressive, some of these shots are extreme close-ups, leaving little room for error. The shattering soldiers are quite stunning, and I think they will really stick in people’s minds.”
“Getting the right look of the knights was more complicated than just implementing a rigid dynamics simulation,” says Bryan. “This is probably some of the most technically complex work we have ever done. We developed a new system for true volume shattering that fractured each knight in its entirety. After the initial cut, all the pieces have secondary and tertiary fracturing until the knight has been reduced into a pile of shards. It was a very interesting and stylized way for the director to convey violence without being gory.”
Pixomondo created a procedural system that would accurately break up each knight along the strike points and allow artists to change animation of either the knight or his attacker and then run a new breaking simulation. Simulations are often unpredictable, so the flexibility to adjust shattering parameters or animation on the fly, control the fragmentation timing, and quickly re-simulate the effect were key to achieving the desired results.
“Overall, we created more than 1,500 digital knights in the first battle sequence, and a major challenge was making each knight feel unique, instead of an army of clones,” Roberts said. “To get around this, in addition to diffuse, reflection and normals passes, each character was rendered out with a unique character ID, which we used in comp to vary hue and luminance, giving each knight a distinct look.”
“Seamlessly mixing the live and CG performers posed an additional challenge,” adds Andrew. “We took data from the matchmove camera and from the lidar terrain directly into comp, and were able to develop a smooth pipeline to make much of the CG work totally invisible to the audience.”
The opening battle sequence also featured a number of wide establishing shots that required terraforming to change a lush forest clearing (where the battle was shot) into a desolate space clearly showing the wear of war. Artists digitally scorched the terrain, removed excessive greenery using 2D and paintwork, and added in 3D simulations of fire and smoke for aerial shots. Pixomondo digitally enhanced the shadow army as well, filling out the king’s cavalry to effectively quadruple the size of his forces by expertly placing CG horses amongst the live-action animals.
Additionally, Pixomondo contributed to the final assault on the Queen’s castle toward the end of the film. Sharing work with BlueBolt, who created the castle, Pixomondo enhanced the battle by adding arrows, archers and fireballs. It digitally redressed the beach to make it seem like a wider expanse and supplemented the armies with digital soldiers and horses that amassed on the cliff overlooking the castle. Blending the digital VFX with practical effects, Pixomondo augmented real-life explosions in the sand and fireballs thrown by the trebuchets with CG simulations that matched their practical counterparts, blending in pieces of the practical elements wherever possible.
Above: When the shadow soldiers are struck, they fracture into shards of obsidian glass, with additional shatters radiating outward.
Though the project was based at Pixomondo’s Los Angeles facility, artists in Toronto, Beijing, Shanghai and Berlin played an important role in the creation of the complex effects. Bryan and Andrew in Los Angeles, alongside Mahmoud Rahnama in Toronto, supervised the shattering knights work. Patrik Witzmann and his team, also in Toronto, augmented burning buildings with CG. Beijing’s Thomas Lautenbach oversaw crowd duplication of soldiers, digitally adding horses and expanding the troop ranks. Artists in Shanghai enhanced the last battle sequence, while the Berlin team, helmed by Pieter Mentz and Michael Lankes, completed all the fireball work.
Read our interview with Pixomondo's Oscar-winning VFX supervisor Ben Grossman about his work on Hugo, which picked up the Academy Award for Visual Effects earlier this year.