Mesh + normals map causing 'hard' seams on every curved face on curvature map

LuckyNinja

Mesh + normals map causing 'hard' seams on every curved face on curvature map

Hey there everyone I'm having a problem trying to bake my curvature map for part of a model. I noticed this with Painter, but as near-enough the same thing's happening with xnormal's baker, I figured technical talk is the more appropriate place.

Basically, every time I bake the curvature map, seams appear on every curved surface, regardless of the smoothing groups. In Painter each face is rendered in a different shade, while in xnormal seams appear on every face. [img]https://i.imgur.com/Jh4JCBg.png[/img] [img]https://i.imgur.com/bCMsA3D.png[/img]

Now I've figured it's due to a combination of the mesh and the tangent-space normal map / high poly, but this doesn't help me.

So I thought it might be caused by the mesh smoothing, which did get a bit janky when I reduced the poly count on the model [img]https://i.imgur.com/qdSVNlY.png[/img], which is the same bit up in the example, BUT, it's also doing it on areas where the smoothing is completely fine [img]https://i.imgur.com/6Nkg5Bz.png[/img].

If you look at the normal map, you can also see these slight lines [img]https://i.imgur.com/1SVnD7l.png[/img], but they don't display on the model when applied [img]https://i.imgur.com/EZXOBk7.png[/img] so I'm not sure how they're causing the lines. i should point out that these lines correspond to the high poly's topology, so I thought it might be an issue with the high poly, but the smoothing groups on that are fine too (and to double-check I also applied one smoothing group to the high poly, which didn't have an impact on the result). 

Now, things like the ambient occlusion bake fine on both programs, and don't seem to be affected by the high poly (as I understand it, xnormal computes AO with the highpoly, Painter uses the low poly + Normal) [img]https://i.imgur.com/W4I41QA.png[/img] . 

The whole thing is confusing for me because I've also baked another part of the model, and while I've noticed there is this issue of a few parts of the mesh (again with the smoothing), the effect is nowhere near as severe, and in areas with no smoothing jank, the issue doesn't exist at all.

So, what do I need to do to fix this? I mean, I understand I could probably alter the smoothing groups / add some chamfering for the areas with the dodgy smoothing, but what do I do with the areas where there's no smoothing weirdness going on? Alternatively, is there an alternative way of generating the curvature map? cheers guys!