  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.
