Bug Normals fragmented when FBX exported to Unity with textures from Adobe Susbtance painter.

Hi, I'm trying to troubleshoot this issue we've seen in our pipeline which goes PiXYZ -> Substance painter -> Unity.

We export a mesh (FBX) from Pixyz, and import it in Substance painter for baking from hipoly mesh and texture painting. We then take those textures, and import them together with the exact same mesh into Unity but can't recreate the look of the mesh as seen in Substance painter. Instead, the normals of the object look fragmented or erroneous.

However, If we instead EXPORT the mesh from Substance painter and use that mesh together with the baked normal map the mesh looks fine in Unity. All other import settings are harmonized.

This leads me to either assume Substance painter does something to the mesh or normals upon import, but not declaring quite what. Or if PiXYZ somehow omits something from the FBX.

Can't really wrap my head around this. Anyone have any ideas? Has anyone seen this too in their workflow?

I've tried posting on the Adobe forum aswell to see.



Original FBX with substance textures in Unity, looking bad:



Re-exported FBX from substance with substance textures in Unity, looking good.


Regards
- Björn

 

Hi Laurent,

Yes, I do that via script but I've tried via the menu as well. Does not seem to do any difference.

Code (python):

1.  # Create tangents and normals
2. algo.createNormals([_proxyMesh])
3. algo.createTangents([_proxyMesh])

 

Hi Axel!

Here is a snapshot of my import settings. I should say they are the same for both the Pixyz-exported mesh and the Painter-exported mesh. What I'm comparing here is what you mention - one on hand importing mesh directly to Unity from Pixyz. and on the other hand comparing that with the mesh exported from Painter. That's where I see the difference.

I create the Low poly model in Pixyz using this code summarized:

Code (CSharp):

1. # Create a proxy from meshes
2.         _proxyMesh = algo.proxyMesh(occurrences, voxelSize, ELEMENTS_FILTER)
3.  
4.         # Decimates the newly created proxy mesh to optimize polygon count
5.         algo.decimate([_proxyParent], 0.5, -1, -1, -1, False)
6.        
7.         # Create UV maps
8.         algo.mapUvOnAABB([_proxyParent], False, 100.000000, 0, True)
9.    
10.         # This line seems to crash PiXYZ.
11.         # algo.automaticUVMapping([_proxyMesh], 0, 0.500000000000, -1, True, True)
12.            
13.         algo.repackUV([_proxyParent], 0, True, textureSize, padding * 2, True)
14.         algo.normalizeUV([_proxyParent], 0, -1, False, False)
15.        
16.         # Copy UV channel 0 to 1.
17.         algo.copyUV([_proxyParent], 0, 1)
18.        
19.         # Create tangents and normal (for easier baking later)
20.         algo.createNormals([_proxyParent])
21.         algo.createTangents([_proxyParent])

I have the opportunity to bake maps (like normal or ID map (diffuse)) in Pixyz but I resorted to baking all the maps in Painter using the Hipolymesh as reference because I knew I needed to bake certain maps there anyway which Pixyz wont let me bake - and I also got the impression Painter did an overall better job with an easier tweaking interface when baking normals.

In substance painter, everything looks good without artifacts. The mesh I export from Painter looks good in Unity.

I've attached a zip file with the files and how to try to reproduce:

1. I've created a proxy mesh with normals and tangents and UV which I've exported alongsside it's LOD0 original as FBX.
2. Import Platform_LOD1_fromPixyz.fbx in Painter, and bake texturings using Platform_LOD0_fromPixyz.fbx as reference hi-polymesh.
3. Apply any material or no materials at all, and export textures.
4. Also Export the mesh (File -> Export mesh) to Platform_LOD1_fromPainter.fbx from Painter and import both that one and the original Platform_LOD1_fromPixyz.fbx to Unity and apply a material using the exported textures.

Here are screenshots from Painter:



And pictures from Unity showing the Pixyz mesh first and the Painter mesh second



Regards

- Björn