Sorry for the delay in responding.
I would start with much of the proceedings of last year’s Radiance Workshop (especially the part about the new Radiance from Greg Ward, but also including Jan Wienold’s DGP update and Mehlika Inanici’s HDR sky imaging).
I would also check out the Lark Spectral Lighting approach for the background (versions of Lark at present rely on Legacy Ladybug Tools and use the RGB Radiance approach to build up to 9 parts of the spectrum) Lark Spectral Lighting
I would also make available as standard the MEASURED materials on Alstan Jakubiak’s Spectral Materials database Spectral Materials Database: About (mentioned previously Aproposal for an enhancement to the Material Definition - #3 by MichaelDonn)
Given the topics Radiance and HDR workshop 2025 ‒ LIPID ‐ EPFL I was hoping my post could also update against the content of the 2025 Radiance Workshop. But, not yet.
References:
Essentially, Metrics for daylight calculations (research report) (2015) (pdf) | CIBSE for theory
RI05: Weather data for daylight modelling (2022) (pdf) | CIBSE for weather file theory
and possibly:
https://www.cibse.org/knowledge-research/knowledge-portal/lighting-guide-02-lighting-for-healthcare-premises-2019/