Wrath of the Titans: Giving Strength to Kronos
From the outset, director Jonathan Liebesman wanted a more grounded and less "magical" approach to Wrath of the Titans. This naturally extended to the VFX provided by Method Studios, with the work being divided between the London and LA facilities, under the supervision of Olivier Dumont. The onset VFX supervisor, meanwhile, was Nick Davis.
The main sequence for Method in LA involved the awakening of the monstrous Kronos, father of Zeus (played by Liam Neeson). This fully CG rock giant is brought to life with glowing lava and causes the cataclysmic destruction of the Underworld. During pre-production, Method in London created concept images for the production's art department, as well as the VFX in the establishment of the Underworld sequence.
The Kronos sequence included 114 shots featuring the CG creature in a fully CG environment consisting of more than 7,000 pieces. The action takes place in a huge collapsing chamber, with Perseus (Sam Worthington) and Andromeda (Rosamund Pike) freeing Zeus as Kronos awakens. Digital doubles of leading actors were created and composited into scenes along with fire, smoke, explosions and flowing lava. For the Underworld establishment sequence, Method London's challenge was to get across the massive scale of the CG environment, which included detailed matte paintings and the creation of a stone pillar tower that Zeus is later bound to. In this VFX intensive scene, Zeus is drained of his powers as fiery lava bleeds from his arms and flows into the surrounding rocks to give Kronos strength.
"The big challenge was the destruction of the mountains -- what we call the pyroclastics -- and also all the lava and the animation of Kronos itself," Dumont explains. "The way we were briefed at the beginning was that Kronos wasn't supposed to move that much, and so we built our animation for that. But during post- production, they altered the plan and the director wanted Kronos more mobile and to be seen getting free. This was in order to add more dramatic tension. And so we had to make a major adjustment."
The sequence is split into two primary locations pertaining to the tower known as Tartarus: outside where Kronos is bound and inside where his awakening is revealed. The outside was comprised mainly of 3D matte paintings for the set extensions and Tartarus reveal. The inside required full modeling and texturing. There were three stages for Kronos, who is attached to the mountains: sleeping, awakening (yet still static) and moving with massive destruction occurring all around him. (MPC was responsible for the post-awakening of Kronos for his climactic battle outside.) The animation was done in Houdini (with augmentation by Nuke). Everything was built and textured as blocks; and then merged to simplify the model and to render. ZBrush was used for modeling and Mari for texturing. MPC handed over a low-res model of the base along with the main design of Kronos when he's on the surface. But Method was able to adjust the look of Kronos to fit their needs.
Pyroclastic effects were used when Kronos breaks free and they used lots of reference from Hawaiian volcanoes. Large pieces break into smaller ones and they eventually become fluid.