Well, i have merged my project with the sun position calculator and my system is behaving pretty much like it. Surely it still can get better and the Moon rotation needs more work, still will try to make it better in future updates.
If you want the stars to rotate only in one direction instead of following the Sun’s trajectory, you can do a fake rotation for them like in the instructions bellow:
Open the material and break the SkyAtmosphereLightDirection connection to the ReflectionVector
Then open the Blueprint, go to event graph and do this:
But I have another issue, when the sun is moving there is a weird effect where the sun and its lensflare is “flickering”. It can be seen the first seconds in your video:
I have no idea why this is and it doesnt look very nice…
That’s simple, i found out that it’s the Sun’s Source Angle causing it. Increase it to a bigger value like 2 that it stops happening, and set the bloom to a lower value or 0.