Workflow with 2 UVs ( Alex senechal tuto ), issue with visible seams

Alecc

Hey guys

I'm trying to reuse the same workflow that Alex Senechal : https://www.artstation.com/artwork/eVm0P
Long story short : 2 uvs workflow, on the first, the baked textures ( trim and decal ), and tileable on the second UV

everything is almost ok, except that : 



This seam doesn't appears in the different Buffer Pass ( Metallic, Roughness, World Normal etc...)
and I tried everything to remove it....
I've found few hints on the forum to resolve this , without success ( no rotation of the uvs, avoid to scale non uniform etc...)
I tried to setup a very simple shader, still the same problem.

I'm using the layer system but for the tests, I disabled all extra layers ( dirt etc...)

I'm on the latest UE5 version.

This problem makes me crazy....

If you have any idea....it could be very usefull

Thanks a lot

Fabi_G

Hi! Perhaps share some more information how you implemented this in the material. It's likely I came across works of Alex on AS, but am unfamiliar with his tutorials/ specific workflow.

Best attach files that allow re-producing the issue (zip and attach to post). If you don't want to share the whole model, isolate an area that's displaying the issue or create a test case.

Sempoo

In what software do you do texturing?

Alecc

sorry, I didn't see the answers :d 

complicated to attach file, it's heavy  
It's a workflow similar to Star citizen workflow, but here we don't use defered decals on top of the meshes, and we use UV1 for having the Decals / trim and UV2 for tileable.
I tried to setup the easiest shader ever in UE5 ( just the normal map ) and I still have this issue

I used Substance Painter 11.0.2

Fabi_G

Hi! Don't understand how such a file could be too heavy, it would be a mesh and the two normal maps that should get combined. No high poly or anything like that. In my opinion it would be best do a simplified test anyways. 

If remember correctly, in UE4 only tangents of UV0 were stored. To use a tangent space normal map with a different UV channel, its tangents had to be calculated. Perhaps this is still true in UE5? If you're following a tutorial and it still works like in UE4, I would hope it's covered. Here are some of the old UE threads: Tangents only calculated on UV0?. Long going thread, unfortunately broken images: Multiple Normal Maps on Separate UV Channels?

Don't know if this is the solution to your issue. Best provide some test assets.