I'm baking a normal map using a high-poly mesh and a low-poly mesh. Things seem to work out, except some UV-islands are... inside out?
In unity it looks like this:
The left image has normal map strength set to 2.0 (exaggerated for clarity) while the right image has normal map strength -2.0
As you can see, in the left image the left wing is inside-out while the right wing is correct. In the right image it's vice versa.
I have tried normal recalculating, flipping etc.