About exporting normal maps

[Michel288328666h2h]

Hi everyone,

I have unwrapped a model following the automated process.

I have checked the normal map in S3DP: it looks good and has black background between the islands.

After exporting it, I've got a different map having purple/blue color for background with artefacts.

The question is: is there any setting allowing to get black background between islands, like in S3DP, after export?

I think it would be better for visualization.

Thanks a lot!

[Michel288328666h2h]

Any idea maybe? Thanks.

[davescm]

Check your padding settings in Export >Settings> Global (and by individual texture set if overridden). The screenshot you show is expected when padding is set to dilation infinite.

Dave

[Michel288328666h2h]

Hi,

Thanks for reply.

Unfortunately it doesn't solve the issue.

I tried first "Dilation + Transparent" and then the other options.

[davescm]

Can I ask what is to solve? The use of padding (dilation) is both expected and normal practice as it avoids issues along the seams with mipmaps.

Dave

[Michel288328666h2h]

Sure.

When I import the textures, the space between the islands is not black, it is purple as shown on the first screenshot I uploaded.

I have a black color in Substance 3D as shown in the second screenshot.

Dilation is infinite but when I change it to transparent it doesn't solve the issue.

[davescm]

Having no dilation and black right up to the UV edges can cause visible issues in the seams when rendering. To rephrase my question - what issue are you having by not having them black?

Dave

[Michel288328666h2h]

If you say that having black color between islands could be an issue for rendering, in this case we can keep it so.

My last question is: why are there such artefacts and not uniform purple color?

[davescm]

The padding works by extending the colour outward from the edges, so whatever colour is on the normal map edge pixels is extended outward into the unused UV area. If a standard normal colour was used then that would also potentially show as a seam artifact on rendering.

Dave