Black shading on metal surfaces?

morepolys

I think this is probably just my misunderstanding of shading and normal maps, but I started noticing the more reflective my surface was the more this black shading started to show up on my baked model.

So on the left is metalness of 0, and on the right is 1.  There's a noticeable black shade around areas.  Is this just because my highpoly is too extreme on the bevels or is this expected behavior for overbaked reflective surfaces?

EarthQuake

This is completely normal, and just one of the drawbacks of using normal maps to represent a bevel rather than actual geometry. What you're seeing here is a thick bevel in the normal map, but a 90 degree angle in the low poly, so that normal map detail sort of "wraps around" and shows you a part of the mesh that you shouldn't technically be able to see at certain angles.

If you bevel the low poly this can be improved, but generally speaking this isn't something you should worry about - assuming the player won't be able to zoom in super far on the asset.

morepolys

Awesome thanks for the clarification!