I have a question regarding odd artifacts in substance painter.

SamDesigns

So I am fairly new to UV unwrapping things but I get the idea behind it and how to do it. But I am running into an issue with a design that is more organic than usual and I am getting odd artifacting on the edge of the UV seams. This hasn't happened with other things that I have made before. I looked into increasing the UV padding and it's set to 32 pixels which should mean that it doesn't bleed into the other parts of the design but I am still getting the same artifacting. Does anyone know the root of the problem? Something I can look into and learn more about?

Fabi_G

What do the UVs look like? Straightening UV borders and aligning them with the pixel grid can help reduce artifacts on seams. Another thing would be to move seams to areas were they are less prominent.

Yet another approach, that becomes interesting when the object has repeating parts (tiling border strip around the object), you could add a tiling strip to the texture and map the border UVs to it. Prevents individual ao/masks for those areas, unless using a second UV channel with unique UVs.

Here is the wiki article on padding: http://wiki.polycount.com/wiki/Edge_padding You might find some more articles that are interesting there. Using the forum search you might find threads discussing issues similar to yours.

Eric Chadwick

Also more about trim sheets here
http://wiki.polycount.com/wiki/MultiTexture#Trim_Sheets

SamDesigns

Yeah so some of the UV's aren't that straight which could be the reason but it is aggressive on the curving surfaces. Also it has a ton of bleed on those edges, does having them not straight really affect them that much even on 4k textures? 



It looks like even on the "straighter" UV's there is a ton of bleed on the edge.

Fabi_G

Hi! I would straighten the strips. Them being almost straight still means the UV borders are cutting pixels at an angle (https://helpx.adobe.com/substance-3d-bake/common-issues/aliasing-on-uv-seams.html)

A high texture resolution doesn't necessarily solve the issue if the UVs are mapped to just a few pixels. I would test if 32px padding is necessary (lowest mip map?). If not make use of those pixels. Here is an insightfull post by Earthquake: "4k texture, and we use 32 pixels"

 https://polycount.com/discussion/191707/padding#:~:text=4k texture, and we use 32 pixels

How do the seams look with just the mesh maps applied? I believe by using different height values on adjacent parts, one can pronounce UV seams too.

Of course all this is a guessing game. Feel free to share your files (zipped high + low) for people to take look on their end.

SamDesigns

Yes it might be an issue of using different height maps in areas. I ran some tests with some other shapes and most all of them were unwrapping just fine with different hard shapes. I might have messed up somewhere in the modeling stages of the part. Thank you for all your input however, It helped me look into some of the problems!