Bake details along uv seams: a clarification pls

Conte_Hamlin

Hi to all, i'm searching a gentle soul that can finally clear up to me a basic one: how to obtain a scratch or a detail along a seam using a texture baking software like Substance Painter or so?

Let's assume that i've a tank or gun low or mid poly mesh and in my high poly mesh i'm going to sculpt in zbrush my tear & wear scratches and so also along the borders of the shapes; in my uv layout i'm forced to cut the uv island along the same borders.. i'm doing several test on my meshes but i'm not able to aware completely the seams so the scratches details going to be sometimes baked with some seams and discontinuity.. 
I'm not able to find a tutorial for that specific topic so i'm not able to know if my purpose isn't achievable or so...

Here i've opened a topic specifically on sub painter, but i'm wondering if any other application can do the job better!

https://forum.allegorithmic.com/index.php/topic,17852.0.html

So there's a method to completely hide a seam or is a matter of hiding tricks?

Thanks in advice!

jaker3278

Are you baking using a cage?  If your not you are using explicit mesh normals of the low poly for projection.

Look here

An unsmoothed cage uses the explicit mesh normals of the low poly for projection. This method results in gaps or seams at hard edge borders and is generally not recommended. The main benefit of this method is that it can result in less skewed detail

Look at https://www.marmoset.co/posts/toolbag-baking-tutorial/ for baking info that you should read. 

Conte_Hamlin

Hi, thanks for the reply!

I'm using Sub Painter with averaged normals. No cage.

I'm already able to avoid that you explain, my problem come when i want to bake details like scratches along the seams (like an edge scratch of a weapon or a vehicle)..

Like that:



Now i found a solution to partailly avoid this, and was to soft the edges (not in a smoothing group meaning, but literally enlarging the chamfer on the mesh) in my low poly mesh.. but when is time to apply materials or so the seam come back visible in some places..

jaker3278

Have you tried increasing the padding? I would try baking with a cage aswell that way you know for sure what you are getting. Using the min and max ray trace values can be unpredictable. 

Conte_Hamlin

Padding in Sub Painter is automatically generated: it stretch a pixel until it reach an other UV island or the border of the texture..

Cage is a bit difficult to make in that model (i think) because i have an amount of 100 parts and some are really intricate so...

jaker3278

http://polycount.com/discussion/177780/difference-between-substance-painters-average-normals-baking-and-a-traditional-cage-workflow heres a thread about average normal baking might be useful not sure. 

I still think you should add some padding i think painter works with both the padding and the apply diffusion. 

How do you have your smoothing groups setup, are you setting smoothing groups to uv islands. The rule is if you have a hard edge e.g a smoothing group you must split your uvs. 

Conte_Hamlin

I'm using high poly mesh as project mesh in SP so i don't need to manage with smoothing groups for let my model shade correctly; so i've set 1 single smoothing group for each texture set as Wes of Allergorithmic suggest in a tutorial on high poly meshes.. 
According to this, all the concerning about the hard or soft edges in a "maya" language (smoothing groups subdivision basically) fall down in my case..

Changing padding didn't do the job

jaker3278

The only thing i can think of is that you double check you have one smoothing group for each texture set, as you said. You might of missed something. Other than that i'm out of ideas, maybe someone else has more ideas for you. 

Conte_Hamlin

NP, thank you!