Normal Map doesnt use the correct UV set

[Anonymous]

Hi there,

I have an object with 2 texture sets, one tiled in several UDIMs, the other seamless in one UV Tile.

I have linked the file nodes via the Relationship Editors UV-centric UV linking, and they all work fine. Except for the normal map, which is connected to a aiStandardSurfaceShader via an aiNormalMap node.

I have also tried the bump2d node with tangent normals, with the same result.

Any help is greatly appreciated!

[cavescholar]

Hello, just a suggestion but what happens if you connect the Brown_dry_mud_nor_4k.png out color pin to the normal pin on the ainormalmap1 node? Also, maybe try wiring the out color pin of Brown_dry_mud_nor_4k.png texture straight into the normal camera pin of the aimud1 node directly, without the ainormalmap1 node. 

Since you say the others are working, the difference that could be causing this is that AiNormalMap1 node, unless you can wire-in place2dTexture3 UV into AiNormalMap1Node somehow, because it is the only node that is not directly connected to the place2dTexure3 (UVs). 

Just a few thoughts, good luck!

[Anonymous]

Hey @cavescholar, thank you for your suggestions. I experiemented a bit more, didnt find a real solution, but a workaround.

I exported and reimported the mesh as an OBJ, after which it had only the seamless UV set (deleting the UDIM set should work too).

Then I created a second set, into which I transfered the UDIM UV set from the original mesh (using attribute transfer).

The normal map now uses the correct UV set. I believe that the ainormalmap node somehow uses the first created UV set by default, but i might be mistaken.

If anyone know the reason for this strange behaviour I would still really like to know.

Thanks!