Substance and Unreal 4, texture differences

emerald-shine

So I have  a character with normal maps I baked in substance painter and it looks good in unreal.


I slapped a quick texture together to get a feel of how it would look and the result was less than stellar.



Now Im not great at substance painter but it didnt look THAT bad...



Theres probably plenty of diiferences between substance and unreal that cause this visual mess. Can anyone explain what these are and how I can get my texture in unreal to look at least somewhat as good as it does in substance. The normal map looked great before I tried adding colour. What is that awful seam, why is she so shiny and why is the normal map barely noticeable now?

GlowingPotato

For metallic and roughness you need to disable the sRGB for the texture in unreal, those are Linear values. Only color is sRGB.
That seam on the chest, looks like a normal problem.

emerald-shine

Thanks, disabling sRGB for metallic and rougness helped with the shinyness.

Looking closer at my normal maps, yep, deffintely looks like a normal issue which puts me in a tight position. The character has a skeleton with fully painted skin weights and animations.  If I make any changes to the UVs to fix that seam and bake it going to cause problems isnt it? I'll have to seperate all the parts of the mesh for substance, but doing that will reqiure me to detach the skin from the skeleton and then need to re-skin her weights again. Maybe even re-do the animations. Cant beleive I only just noticed that. The white was blending that seam and got so used to it.

Is there anything I can do at this stage to fix this, I really dont want to redo all that again.

ActionDawg

I dunno what software you're doing the rigging in, but the skin wrap modifier in 3ds max allows you to transfer weights from one mesh to another and then reskin. They don't even need to be the same topology. You can auto rig a low poly from a rigged high poly, or rig a high poly from a rigged low poly! This feature really has tons of versatility.

I'm sure this reprojection feature is present in some form in other programs.

emerald-shine

That does sound really useful. Im using Maya. I cant stand Max at all, definately not for me So in theroy. I could duplicate my character(s) mesh, transfer the weights onto it, detach my orginal from the skeleton, sperate the parts again for substance, fix UVs, get a clean bake in substance, combine the parts again in maya, transfer the wieights from the duplicated mesh back to the Updated one and hten reskin. Also since the skin weights will be the same I wont need to alter the animations right?

Am I thinking on the right lines here or am I way off in my understanding?

musashidan

I'm also using Max but I believe you can transfer uvs in Maya. So you might be able to just re-uv your static t-pose mesh (that I'm assuming you have saved somewhere before rigging/skinning) and transfer the uvs to the rigged mesh.

emerald-shine

musashidan said:

I'm also using Max but I believe you can transfer uvs in Maya. So you might be able to just re-uv your static t-pose mesh (that I'm assuming you have saved somewhere before rigging/skinning) and transfer the uvs to the rigged mesh.

That sounds like it might be easier. I do have a static pose of both characters before they were rigged and parented together, Ill look into that.

However Im wondering if really is my UVs that are the issue. I tested my the cat to see If he had this problem and sure enough..

It seems any where I have cut the UVs to unfold them as required has resulted in a fairly ugly seam. I know my UVs arent great, but i didnt think they were terrible. i understand you make your cuts where people arent going to see them, the sole of a shoe for example. but sometimes for organic shapes especially, theres no way to avoid it making the cut out of view such as a characters neck for the face. Anyone have an idea what im doing wrong. The low poly model normals are smoothed at the seams before exporting to substance. The witches torso UVs are mirorred (wasnt intentional BTW) so they should match up properly right?

AtticusMars

You need to post a picture of the high res mesh for comparison if you want a better answer. But simply looking at your image, you clearly have some of the seams because your map has no edge padding.

emerald-shine

Update:

Here he is without a normal map applied and just a fill layer. The seams are still showing up. I Tri planar projection looks better but those seams are still visible(previous screen was aslo set to tri-planar . Model is clean with no non-manifold geomotery. This is drving me spare.

musashidan

I'm pretty sure this is an SP bug with their implementation of tri-planar projection. I've noticed similar seams when zoomed in close that should never be present using a non-specific-patterned texture with  tri-planar projection. And because the texture itself in the tests I've done carries across the UV seam as it should, the seam itself is always visible, which leads me to think it's a bug.

emerald-shine

AtticusMars said:

You need to post a picture of the high res mesh for comparison if you want a better answer. But simply looking at your image, you clearly have some of the seams because your map has no edge padding.

Do you need a shot of the High res mesh with its UVs? If so, the high meshes dont have unwrapped UV's because Ive been told they dont matter. How do i set up the edge padding?

musashidan

No, you don't need uvs on the high poly. The sole purpose of the high poly is to rip the detail to the Normal map. You set up edge padding in your unwrap. You can specify it as a number if you autopack the shells or do it manually. It means having enough pixels between the shells so nothing bleeds across to adjacent shells causing errors. It's also used for mipmapping. This is what the dilation is in SP.

emerald-shine

Ive never had a problem with edge padding before. Ive always used photoshop and made sure I had enough room for the textures to bleed out of the UV shells and its always worked. The only time the seams were noticable was when im texture didnt quite match up at both sides of the seams.  Ive never had to mess with any settings for this.

I may have found a soloution.

I made a new project in substance and imported the low mesh. Didnt bother with baking and hand painted over the model. No fill layer or anything. The only thing I used was a fur material and a brush. I exported the textures with the Unreal setting and got them into it. Made a fresh material, used my new textures and the same normal map I was using before and no ugly seams. It still doesnt look as good as it does in substance but it does look clean.
While im happy I may have found a work around, im still irritated that I do know what the issue is and exactly what i did to get get around it.