Physically-Based Realistic Fire Rendering

Figure 1: Simulation of a methane pool fire, a fully path-traced scene where the flame is the unique light source, and a scene where refraction effects cause the straight wood stick to appear warped, all rendered using our physically-based fire rendering technique Accurately rendering fires is a challenging problem due to the various subtle ways in which the electromagnetic waves interact with this complex participating medium. We present a new method for physically-based rendering of flames from detailed simulations of flame dynamics which accounts for their unique characteristics. Instead of relying on ad-hoc models, we build on fundamental molecular physics to compute the spectrally dependent absorption, emission and scattering properties of the various chemical compounds found in the fire. Combined with a model of the refractive process, and with tone-mapping techniques simulating the visual adaptation of a human observer, we are able to generate highly realistic renderings of various types of flames, including colorful flames containing chemical species with very characteristic spectral properties. Categories and Subject Descriptors (according to ACM CCS): I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism- Ray-tracin