Non-Orthogonal Reduction for Rendering Fluorescent Materials in Non-Spectral Engines

TL;DR

A method to accurately handle fluorescence in a non‐spectral (e.g., tristimulus) rendering engine is proposed, showcasing color‐shifting and increased luminance effects, and it visually matches full spectral light transport for measured fluorescent materials even for challenging illuminants.

Abstract

We propose a method to accurately handle fluorescence in a non-spectral (\eg, tristimulus) rendering engine, showcasing color-shifting and increased luminance effects. Core to our method is a principled reduction technique that encodes the re-radiation into a low-dimensional matrix working in the space of the renderer's Color Matching Functions (CMFs). Our process is independent of a specific CMF set and allows for the addition of a non-visible ultraviolet band during light transport. Our representation visually matches full spectral light transport for measured fluorescent materials even for challenging illuminants.