what is the new reconstruction method? Is it this now RGL | A Low-Dimensional Function Space for Efficient Spectral Upsampling ?
EDIT: apparently there is a variant that can do even wider gamut spectral upsampling by going into flourescence. Not sure if that’s a thing we want to pursuit immediately but might as well share. It seems to be a cool option for sure
Wide Gamut Spectral Upsampling with Fluorescence
Plus followup to that paper:
Improving Spectral Upsampling with Fluorescence
And another paper seems to even discuss spectral Rendering in both the Offline (Cycles) setting and Real Time so that may also be interesting to look into. Maybe some spectral stuff could, in fact, eventually be supported by Eevee! (Sounds like the spectral realtime engine they have built is currently fairly limited though)
Using Moments to Represent Bounded Signals for Spectral Rendering
Plus a follow-up to the above: