Need help with smoothing/baking

Monkfish

Hello everyone. I recently followed a tutorial for Zbrush and made a HighPoly knife. I decided to push this prop even further and made a LowPoly, baked it and textured it.
Unfortunately I ran into a problem i cant solve myself.               PLEASE!! I appreciate any kind of help.

As you can see there are some smoothing issues on the blade right in the middle.
Blade has mirrored UVs and I set the same smoothing group for both UV islands (marked with red arrows). Maps where baked in substance painter with Template set to Unreal Engine 4. Set to DirectX, Compute tangent space per fragment.
UVs

this is the topology of the low poly
these are my bake setting for normal map

These are my FBX export settings for LowPoly.

Now what i have tried and it didnt work: First i thought the seam is visible, becase i did something wrong while texturing
(projections based on UVs etc.). I deleted everything and put on single fill layer with metallic - 1 Roughness - 0,3.  => Seam is still there.

I also went to Project Configuration to replace my low poly mesh with a new low poly that has Unique smoothing group for each UV island and went to TextureSet Settings to rebake the normal map. No luck. ( Or should i use different aproach for the rebake?)



I also skipped through the channels to see the normal only - result.

Well I think i provided as much information as i could. Do your magic polycount!

Monkfish

Did some more searching a tests.. and it seems my problem is in the rotated UV shell. If I have UV shell split in half like on this blade, I should maintain same orientation in the UV space. Therefor i have to repack, rebake and do some of my texturing again.. Oh well.. Fun

Go2frag

Hi!

You have that 'shading' issue because you made a seam in the middle of the blade. Is there any reason why whole one side of the knife couldn't be just one uv island- it seams to be reasonable problem solver. It's pretty visible area and I would try to avoid it .

If you want to keep that seem look at this image: 


Im not sure if rotation of uv shell would fix the problem.

If I would have to make uv of this model I would go with this: 


Im working in Blender- hard edge means edge which divide smoothing groups
Also check normals if they are not flipped.

Hope I helped  

Monkfish

Go2frag said:

Hi!

You have that 'shading' issue because you made a seam in the middle of the blade. Is there any reason why whole one side of the knife couldn't be just one uv island- it seams to be reasonable problem solver. It's pretty visible area and I would try to avoid it .

If you want to keep that seem look at this image: 


Im not sure if rotation of uv shell would fix the problem.

If I would have to make uv of this model I would go with this: 


Im working in Blender- hard edge means edge which divide smoothing groups
Also check normals if they are not flipped.

Hope I helped  

Hi there Go2frag!!

Thank you for your reply!
Yes, your workflow is certanly correct, but i just tried to prove my theory and it works. Problem was indeed with the rotated UV shell.
The reason why i broke my UVs like this is because i wanted to use the UV space as much as I could. If i were to keep the blade uvs in one part, there would be a lot of unused space.

soo above you can see the original UVs have the same angle in the split area, below a kept the blade in one Island and very roughly aligned the other islands to demonstrate how it would look like.


Anyway i have to say Substance saved me a lot of time. Whole repair (UVs, rebake, textures) took me 1 hour maybe less.

some quick render