Wired magazine has a short new interview with Tim Alexander, Visual Effects Supervisor for
Half-Blood Prince. He talks about how they created the fire and water for the cave scene, from research right down to the finished product.
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"There are not enough CPU cycles in the day to capture the complexity found in the environment," says Industrial Light & Magic visual effects supervisor Tim Alexander.
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"We did a lot of research on molten volcanoes, which have a lot of heat going on but no actual flames," Alexander says. "We collected a bunch of other references, including flares that burn underwater, and showed them to the Potter folks."
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"We emulated all these fire parameters: heat ripples, smoke, buoyancy, viscosity, opacity, and brightness," Alexander says. "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."
.jpg "- Click to view in gallery.")
Visual effects supervisor talks Half-Blood Prince 
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