Thank you! This will be useful!

@oliver2s: Thank you very much from me, too!

Have you tried to retrieve the night/twilight/day/golden hour times as well to blend sun colors, too?

Not yet. It's on my To-Do-List, but has low priority, because I have a lot of other things to do the next 3 months.

@oliver2s and HeelX: Do you have any sources related to the sun light color?

No, I don't have any sources yet.

I am not sure, but maybe Cinema 4D provides some information on the color? (At least the built-in sun can auto adjust to a given time with direction/color, probably the manual has a chapter about that and maybe with citations on how they did it?)

Check the Atmospheric Scattering section in the rendering papers thread. It's basically all about light getting wavelength-dependend absorbed and scattered away while traversing the atmosphere. During dawn and dusk there is more atmosphere the light has to traverse, which results in the color change.

Under very rare conditions the sun pan was wrong for a few seconds around noon in spring and fall, because the value for acos was out of range (-1, 1).

Fixed that and updated the code in the first post.

The code in the first post isn't correct (undeclared stuff from iceX), those defines do not match with the ones which are used in the function itself.

Greets

i just converted the code yesterday to C#.
the defines are pretty clear. one must be replaced with the latitude parameter, the other is just another Rad/Deg-conversion factor