Thoughts on making Cycles into a spectral renderer

[brecht]

@smilebags

This is more of a finer detail which isn’t important if the larger issues brought up earlier aren’t solved, regarding whether or not MIS will sill be usable if allowing the user to drive parameters with the wavelength.

The shader nodes should output a spectrum, either converted from an RGB value or by using a BSDF or emission closures that can sample from a spectrum given a wavelength. There is no need for the specific wavelength(s) to be exposed to users in the shader nodes.

If we do this, just like other renderers, then MIS is not a problem.

2. working on Windows and have heard building blender on windows is near impossible to set up

It’s actually not:
https://wiki.blender.org/wiki/Building_Blender/Windows#Quick_Setup