MetaHuman Seam After Exporting From Maya

[El4an58]

Hi guys, I have a problem that I haven’t been able to solve for a month, I created a custom mh from blendshapes and set up a binding. There are no seams in the maya preview, everything looks smoothed out, but after exporting and configuring in unreal, I see a seam between the head and the body, and the strangeness is that the more I change the angle of the arm lift, the more this seam is visible in lit mode, I tend to believe that something is blocking the normals, but I don’t I can understand that. I use Unreal 5.2

I tried:

1. Different fbx export settings in maya, and also on different versions of maya 2022-2023. (smooth group/tangents and binormals/preserve instances/referenced assets content)
   
   
   
   
   
   
   
   
2. Transformed the attributes of normals repeatedly, also tried to unlock the normals
3. In unreal, I tried to change the color channels for the head, identical to the original MH materials. If I use “Green”, the seam disappears, but there are problems with the eyes, when they are closed on the eyelid of the eyes, black fragments. If I choose “All”, the problem with the eyes is solved, but the seam becomes visible again, so the all mode is more priority for me because it helps me avoid problems with the face
   
   
   
   
   
4. Tried different import settings in unreal for both head and body. Changed normal import method to Import normal/Import normal and Tangents
   
   

None of my methods that I listed above solved the problem, something is blocking the normals and I can’t understand the reason. I will be glad of your help, I’m already desperate. This problem has already been encountered on the forum, but it has a slightly different look for me, the author said that he was able to fix it by changing the parameters of the color channels, but it doesn’t help me or I’m doing something wrong
(MetaHuman Skeletal Mesh Seam Issue (Maya Export))

[vm3ujp61 (Yiwen)]

Hi! Have you tried fixing the model’s vertex color?
My process is the same as yours, but I refer to Metahuman’s character (pictured) and modify the vertex color of the model accordingly, and it work!
Hope this could be helpful !

[vm3ujp61 (Yiwen)]

Hi again! The last time I provided was the vertex color of the official MH character.
In my project, I only made sure that the head of my model was blue, eyes was cyan and the body was black.
Recompute Tangent changed to green channel.

And here is the place to change the meshes vertex color

You could drag the head and body to the scene separately for coloring, which makes it less likely to be painted into the seam.

[El4an58]

Thank you very much, guys, everyone who has the same problem, here is the solution

[El4an58]

I also tried to facilitate the work, I was able to bake the vertex color texture from the original MH, but for some reason the import of the TGA file does not work in UE5, the same problem arises that is described here (Vertex color import from TGA texture not working) a black texture is formed, if anyone has information on how to make it work, please write about it. Also, for some reason, the “Copy” button is not active