I can not adjust my brightness and shadows according to the sky.
I use Thea for sketchup 1.5.07
If I put the sun (hypothesis 1), I have a strong shadow even if the sky is totally cloudy, and if I do not put the sun (hypothesis 2) I have no shade even with a blue sky.
Still, shadows should be sky-based (as here for example: https://www.cgskies.com/sky.php?sky=36& ... &pagesize=).
If anyone can explain to me what can I do?

Thank you in advance and good day to all !
Fabrice