Combustion workflows for the Avatar sequel(s) were built from the ground up, aiming at physical plausibility and predictability, facilitated by careful modeling from molecular-level chemical reactions to large-scale thermodynamics. Onset references for torches, flame bars, and burning Marui villages guided development work across simulation, look development, and rendering. Using chemical formulas and properties of real-world fuels, and tuning pre-mixing with oxygen, allowed faithfully capturing a number of desirable effects, such as "oxygen starvation" and flickering of thin flames, without the need for additional artistic variables. Using our new solver created a consistent look across sequences at different scales, allowing artists to replace library fires with hero solves when interaction or a particular behavior was required.

John Edholm, Alexey Stomakhin, Rahul Deshprabhu, David Caeiro Cebrian, Florian Hu, Caitlin Pope

SIGGRAPH 2023 (Talks)