Zbrush: Bad Padding Displacement Maps (Seams Artifacts)

SPQMan

These seam artifacts occur on any model from it's Displacement Map baked in Zbrush.

I had already created another topic before, in which I figured out what the reason was. Now I realized that this is bad Padding in Zbrush.

Old Topic: https://polycount.com/discussion/235650/zbrush-displacement-artifacts-on-seams#latest

I understand that I can’t fix anything in Zbrush itself, although this is very strange and still requires explanation. But can I fix this somehow differently, in another software?

There are files containing part of the model in which this problem is very visible. You can look at them yourself to better understand the problem (it's better than screenshots). There is also more information in ReadMe.txt.  ("ExampleFiles.zip")

I've been trying for more than a month to figure out how I can easily get clean Displacement Maps from Zbrush without casting the runes and black magic. Without these artifacts... But it's all to no avail. 

I'm hoping someone more experienced with Zbrush can tell me what to do in this situation.

pxgeek

I tried to look into your files but I can't open your zbrush tool (you're probably using a newer version than me, i'm on 2021.7.1)

So I tried some test using Akin Bilgic's files to generate a displacement map and render with arnold in 3ds max (I'm on max 2018...so whatever version of arnold that is)

Truth be told, I don't do a whole lot of offline rendering with arnold/vray etc...but even with mostly default settings, it looks pretty good; at least seam/error free. I'll post screenshots with settings. It could be worthwhile for you to download his ztl and try some tests for yourself:

https://www.cggallery.com/#tutorials

 

SPQMan

Thanks pxgeek, you opened my eyes with this portrait example, but first things first.

The fact is that my model, which has artifacts on the seams, takes its place HERE on the UV map along with many other models from the project, because I use UDIMs. And due to my inexperience, I suddenly decided that I could use SubDiv5+ on these models with displacement maps. But after looking at the UVs of this portrait, I realized that it's all about the size of the UV Shells.

Although, still, if you look closely at some places in the portrait (without wasting time on rendering in Arnold, but in Blender viewport and also without smooth faces), for example, the nostrils or the back of the ears has these artifacts on the seams, BUT yeah, in this case it will be absurd, because they are almost invisible. (I mean the artifacts still exist, but they are barely visible)

As obvious as this problem was, I just wanted to understand what is with zbrush displacement maps. That's a relief. You made my day x100 better, thank you so much.

P.S. yeah i'm using zbrush 2022.0.7

pxgeek

That is a very extreme closeup. You'll probably find seams on any mesh if you're going that close.

Regarding UVs: it's good practice to leave room for padding along the edge of the uv border, doubly so if you're using udims.