Just wondering…
Is the BSDF format that Cycles uses the same one that Radiance uses? Rhino-Grasshopper-Honeybee interfaces Radiance for energy simulations and perhaps there could be synergies if a compatible format was used (?).
I am not familiar with Radiance, but I suppose one could find transformations from Cycles to Radiance and vice versa.
I know that at least Cycles materials have been used to figure out light reflection distribution of buildings by creating a special material that ‘colors’ reflection rays with a specific color, so that the reflection is clearly visible on other objects.
It is probably the same. BSDF stands for bidirectional scattering distribution function. Essentially it is a mathematical function that determines the values at a given angle and in daylight simulation is usually used for complex fenestration systems to decrease the simulation time. It is used in other tools other than Radiance.