Normal map seam along mirrored UV's

mickeyvpn

Hi guys!
Can't find a way to get rid of this nasty seam across mirrored UV islands. Followed Typical Mirroring Workflow and it doesn't work. That's what I've tried without effect:

• Offset mirrored parts 1 unit
• Set one smoothing group
• Set different smoothing groups for each side
• Flip UV faces
• Export FBX and OBJ
  

Seam appears in Substance Painter 2.1 and Unreal Engine 4. Hi-Poly is turbosmoothed version of Low-Poly.
Some screenshot for clarifying(this option with offset uvs, not flipped):

mickeyvpn

I've made some tests, but I didn't find solution how to get rid of seam completely, so question on this is still alive. But for now I've cheated a little bit and hide seams in other places by stitching center parts of UV's.

Froyok

If you change the sampling quality from 16 to 64 in the shader parameter, does it improve ? 16 is usually a good tradeoff between quality and performances, while 64 is much more intensive but should reduce this kind of artifacts.

mickeyvpn

Hi @Froyok
If I change quality to High (64 spp), seam is still there.

christopheduron

Where does this seam come from? Is it from your normalmap bake or your paint layers? Could you perhaps show a picture where the paint layers are disabled so i can view the object as white with the normalmap applied to it?

Froyok

Could you send me the meshes then ?

mickeyvpn

@christopheduron
It's from baked normal map, I've made screenshots with material layers to make it more visible. It's still there if I turn layers off just less visible.

christopheduron

When exporting your meshes out of 3dsmax (if that's what you're using) could you try it as an .fbx files with these settings?

And when importing your mesh into substance painter make sure this option is on with directX:

That's how i do it, and i never have issues baking with SP then. (i also always use a cage though, perhaps that does something).

Froyok

I just loaded your low-poly mesh into Substance Painter, without baking the normal map from the high-poly I have already a seam if I use the "Bronze Armor" smart material. The seam appear because of the "Finish Rough" applied on the bottom layer of this smart material. I don't understand yet why and I will need to discuss with an engineer to investigate further. Meanwhile you can disable this filter and you should be fine.

mickeyvpn

Hi guys, thanks for help.
Issue still didn't solved, but another workaround was founded due to you.
@christopheduron
I've downloaded FBX exporter 2013 for my 3ds Max 2012 and there appear option for preserve edge orientation. After export with this option seam became less visible, but was still there. Other setting that you suggest I was already enabled in previous attempts.
@Froyok
I checked this after you and found that normal channel inside "Finish Rough" made seam more visible. Screenshots below as always:

Seam, in the center line with base material applied, became much less visible after export fbx with preserve edge orientation option


Here I enable all effects like edge wear, dirt etc.

Here I disable normal channel in Finish Rough


Conclusion for now: seam is visible even before any maps were baked, so I think the problem in mesh itself or export bug.