Luma Pictures Achieves Towering Results for "Pirates of the Caribbean: At World's End"
Working in support of ILM, studio ropes in films' spectacular "Calypso" sequence
LOS ANGELES - Luma Pictures' contribution to Disney's new blockbuster Pirates of the Caribbean: At the World's End was, quite literally, a giant undertaking. The Los Angeles-based studio was tasked with creating one of the film's most spectacular visuals, depicting the transformation of a waifish Tia Dalma (Naomie Harris) into the towering leviathan Calypso while lashed to the mast of a ship at sea.
Luma was assigned the challenging assignment by Industrial Light & Magic, the lead visual effects provider to the film, and the expectations for drama, realism and fun were set very high. "ILM was looking for an A-team outsource vendor and we impressed them," said Luma Pictures founder and VFX supervisor Payam Shohadai. "In part, it was because we already had a great relationship with Disney through our work on other creature-driven projects, and in part it was due to our focus on quality work that met their internal standards."
The Calypso sequence was created by shooting Harris on a special effects stage with push ins and tracking moves used to make her appear to grow in size in the frame. Luma's role was to composite those images with background footage of the Black Pearl, the film's principal pirate ship, and to "bind" the growing goddess with a system of CG ropes. The ropes virtually constitute another character in the scene; they have a magical quality, and behave like angry, roiling snakes as they ensnare and squeeze Calypso's body. She, meanwhile, does not take her binding willingly, her violent struggles adding significantly to the challenge faced by Luma's animators and compositors.Integrating the CG rope into the sequence was especially difficult. The complexity of the background environment, including the structure, rigging and movement of the ship, the foggy atmosphere, and the hair and costuming of the actress, made compositing a painstaking process.
Additionally, the rope needed to exhibit both the qualities of a living creature and those of actual physical strands of rope. "It had to have a believable amount of tension as it uncoils like a ball of yarn and wraps around, crossing and recrossing itself," said Luma Pictures texture and environment supervisor Chris Sage. "The rope also had to snap and break in a realistic manner, something we achieved through good, old fashioned hand animation, augmented by debris, particle emitters and animated chunks."
Most significantly, the whole action of the rope had to be precisely choreographed to match the live action elements and to adhere to the film's story demands. "Gore Verbinski (the film's director) had a distinct vision for the 'rope monster,'" explained Luma Pictures visual effects supervisor Vince Cirelli. "It needed to feel alive and become more and more wound around Tia as she grew, eventually becoming tight enough to break. To accomplish that, we created an animated digital double for Tia so that the swarms of rope would properly deform and bend around her as she scaled to ten times her normal size."To obtain reference material, Luma suspended 20-foot lengths of rope from the roof of its production facility and shot them at 60 f.p.s. with an HD camera. "We shot all of the movements that were required for the scene so that the animators would have a better idea of how to animate the rope," explained digital effects supervisor Justin Johnson. "We also recorded smaller strands of rope breaking to study how twine comes apart."
Another hurdle faced by the team was coming up with a way to create the rope in a procedural manner as the amount of rope was constantly changing. The solution they arrived at, according to Cirelli, combined custom geometry-creation scripts with a shader network that facilitated the appearance of thousands of woven and frayed fibers whenever a section of rope got close to camera.
"Since the animators needed to be able to adjust the thickness of the rope, the procedural textures were driven by expressions that allowed the performance to dictate the stretching and tearing of rope fibers," Johnston added.Compositing was complicated by the amount of detail and movement in the background environment, including billowing flags and sails, and foreground actors. Behind the Black Pearl, a second ship, the Armada, is visible and it had to be added as a separate element. "There was a great deal of work done in adding haze and fog to the scene," noted Sage. "All of that was done with fluid simulations. The biggest challenge was layering the fog to simulate depth."
For Luma, working in support of a industry legend such as ILM was creatively gratifying and it pushed the team to exceed their already high standards for excellence. "While Luma often works as part of a team, this was our first opportunity to integrate into a pipeline as large of ILM's," observed Cirelli. "We exchanged a large number of files in a variety of formats and were able to work within their pipeline seamlessly."
