Does layer number affect performance?

I need to set up a lot of layers yo get proper results, i'm wondering if creating too many affects in some ways performance, for ex i got clouds, sky, cloud shadows, rain etc, i need to get 4 layers for them, will this in some way reduce my performance in confront to using just 3 2 or 1 layer for them all? thanks!

If you're talking about mobile, basically anything impacts performance. The fill rate is so low that things like that may well get in the way. If you mean for desktops, I wouldn't worry about it. I typically have between 15 and 20 layers for most of the maps in my game and it doesn't really impact performance negatively. It also vastly improves my workflow, but that's another thing.