[inigyou]

I'm not sure you would need that unless you're making a space simulator. Surely the model just spits out a color gradient which you might as well hardcode?

[mananaysiempre]

There are indeed precomputed LUTs, but apparently you need to be a bit more sophisticated than that if you want your sun angle to be dynamic, and they also did clouds: https://www.ea.com/news/physically-based-sky-atmosphere-and-....