Weird problem with importing meshes to SB or Marmoset

Isiktor

I have been having this problem with a couple models and I have no idea what is going on. 
I made maps in xnormal and the cage in 3d max. Everything I did was fine until I import them to SP and bake the high on. This is what happened 
Some weird square lines show up. I think that the low poly is "poping" through the bake but I dont know how to fix this OR even if this is the problem.

Any help and suggestions would be great so that I can move on!!

Thank you

CharacterCarl

My guesses are that
1. either those lines are seams created by insufficient edge padding during the baking process
2. These "islands" which are showing up are actually pieces of the high poly which aren't welded properly. 
More information would be helpful. Could you, for example, post the normal map texture? That would help in determining the cause of the issue.

Isiktor

I tried going 4k in the maps in xnormals and in substance painter. It worked a bit the lines are still there but less see-able. Here is the normal which i just unwarped in zbrush and do any work on that because i hate it.  

Isiktor

didnt do any work* haha

CharacterCarl

The unwrap might actually be the part of problem. Only judging from the model in the screenshot, I can't make out many of the features in the normal map's layout. I suspect that a lot of the UV borders are running across the face and contributing to the seams in conjunction with UV distortion and not enough padding maybe.
My suggestion would be to either give ZBrush's UV Master some seams to work with (polypaint seams) to minimize the stretching and prevent them from turning up in the wrong place or create the unwrap inside another 3D app altogether (MODO, Maya, Blender, etc.). See if that improves the bakes.

musashidan

This could be aliasing. What AA setting did you bake at?

Isiktor

AA is usually 4x 

Isiktor

Thanks Der i will try that and get back to you

Add3r

Looks like the lack of edge padding in your bake actually.  What I think we are looking at are your UV seams correct?  Without edge padding, and the pixels at edges being at a diagonal, you will get some weird dithering/pixelization issues, causing obvious seams at your UV borders.  Try a bake with UV padding of at least like 5 pixels (I usually use 5 pixels at the very least for padding, sometimes much more just to fill that empty space and for auto texture MIP'ing if it will be in engine) 

Isiktor

how do I do that "padding"? 

On another note I have been trying to make new uv's in 3d max but i dont know how to properly cut it. Does anyone have suggestion/videos/articles on how to make good uvs in either 3d max or zbrush? Also any help on retopo would be great! I know how but properly not so much 

musashidan

Padding is originally setup when you pack your uvs. It just means allowing sufficient pixels between shells to allow for texture bleeding/mipmapping. 

As for cutting up your uvs, this is something you have to figure out. It's a balancing of the number of seams to the amount of distortion. For your head model you can cut it into as many shells as you need in relation to minimising distortion. Because you are texturing in a 3d painting environment the seams are not going to matter as much as they once did. There was a time when people just cut a seam down the back of the head, around the ears, unwrapped, relaxed, and called it finished. But this is not a good approach if you want to have optimally relaxed uvs.