Chronicling Narnia's Third Adventure
The trick with the sea serpent was that he had a complex rig and had to wrap himself around the ship. "At one point, he opened his body to reveal all these horrifying inspectoid spines," Valdez explains. "This horrified the animators when they first started because there were so many limbs to articulate, but they ended up being a combination of procedural wavelet motions with keyframes. And we did a big motion capture shoot for a crowd library of sailors on the ship. There are a few dozen shots of a full-CG boat and the full-CG crew on the deck and that was pretty easy work for our Alice crowd tool."
A more abstract challenge was how to depict the amorphous Dark Island, which represents the force of evil in Narnia. "We did various experiments with particle and fluid simulations and created an island-sized massive cloud that has an almost octopus form with large tendrils that reach out into the ocean," Valdez suggests. "The trick was to have parts of the smoke contracting and to have the tendrils squirming and twisting to keep the smoke bound to this shape. That took a few months to figure and a lot of rendering development to figure out how to render the complex simulation of millions of particles with internal light as well as external soft shadowing from the sun. It's not quite a character but is a definite presence and connects with work done at Cinesite with the smoke tendrils that appear in other scenes throughout the film. The final battle takes place inside the creature, which required a separate effort throughout the last 200 shots done on bluescreen stages where an entire mood and look had to be established and a certain grade had to be figured out. We used quite a lot of Nuke for that."
Animations were blocked out for each tendril shot using "character" eels to give a sense of position, speed and movement to the mist. The animations were cached, and fluid simulations derived from the data. Houdini renders produced numerous lighting passes for each of the mist tendrils. These included passes for light emitting particles, internal beams and shadows, all of which could be controlled in Nuke to achieve a desired look per shot.