I'm running into this baking error.
(to give context, I'm following a tutorial and trying to get my head around the basics of texturing with substance).
I'm modeling in maya, zbrush high poly, generating maps in marmoset, and then texturing in Substance.
I've been playing around with padding settings in maya but no changes. When I try the settings in Marmoset the line changes to black, or solves the line issue but I lose all the nice AO everywhere else (the ignore groups check box).
Yes, I'm using the _high and _low suffix
Any input? It's pretty frustrating.
A way you could try working around this is creating the low poly as a single, water tight mesh, rather than a series of intersecting meshes in multiple bake groups.
The AO is baked from the high poly objects, so the more divergence between the high and low, the less accurate these intersection areas will be.
Generally the way to solve this is to use more geometry/match the high poly geometry better. However, a simple solution in this case is to scale up the low poly a little to hide the error.
Here I've scaled up the cylinder in the middle example so it just encompasses the high poly section.
It's worth noting that the Two-Sided option in the AO settings will result in a black vs white area for these intersections.