Multiple Scattering Approximation for Real-time Underwater Spectral Rendering

Abstract

We propose a physically-based, multispectral simulation to render underwater scenarios in real time, which also takes into account the RGB response curve of arbitrary sensors. Underwater illumination is mostly governed by multiple scattering, where light is scattered a number of times between particles before reaching the sensor. This phenomenon is therefore very low frequency and can be modeled as a function of depth and wavelength. Our approximation to multiple scattering is based on the measurable coefficient of diffuse downwelling attenuation. We show examples simulating underwater appearance under different scattering, absorption and downwelling coefficients of the Jerlov water types.