Below are some renders I made after implementing direct sun sampling. these are images of a clear, dry sky, with only Rayleigh scattering and no Mie scattering.
I have not yet implemented a realistic spectral emission distribution for the sun, so right now, it's just flat across the visible spectrum. I am using a rough, temporary approach to convert spectral results to RGB. These pictures all use the same exposure, so the luminosities are roughly comparable.
For now, I made the ground an 18% gray, perfectly diffuse reflector.
|Sunrise or sunset.|