We’ve previously discussed ILM’s new technology for fire in the new Harry Potter film, but now they’ve begun to talk about some of the other technology they created for the movie. In an interview with Post Magazine, they discuss how they rendered the film’s penultimate sequence inside a Crystal Cave with thousands of underwater “Inferi”.
“We had both fire and water going at the same time,” Weaver says, “and the two interacting. We had escape bubbles, with the fire going under the water.”
Representing the thousands of Inferi under the water involved normal-mapping: applying a cycle of animation to the character rigs and rendering it, flatly lit, on a card as a sprite. “When we go under the water, with thousands of these creatures,” Weaver says, “the normal-mapping allowed us to re-light the Inferi. This was an innovative way of handling a crowd pipeline that we hadn’t done before and it worked out incredibly well.”
via COVER STORY: ‘HARRY POTTER AND THE HALF-BLOOD PRINCE’ | Articles | Post Magazine.
