The Quest For Fire in the Next Harry Potter
It’s no secret that rendering Fire is one of the trickiest possible materials in all of computer graphics. Wired sits down with ILM’s Tim Alexander to talk about how they did it for the upcoming Half Blood Prince.
Once Half-Blood Prince director David Yates signed off on a visual template, ILM deployed supercharged Linux machines, each loaded with 16 processors and 4 gigs of RAM. “We emulated all these fire parameters: heat ripples, smoke, buoyancy, viscosity, opacity, and brightness,” Alexander says. Processing the massive particle simulations for the 100- by 300-foot firewall was burning up days of data crunching for each frame. So computer graphics artist Chris Horvath spent eight months obsessing over a faster way to conjure impressive flames. “Chris figured out that a lower-resolution particle set still had a fluidy flow,” Alexander says. “The effect looks as if you sprayed propane and then lit it.”