Often, after doing one of these troubleshoots, I then get additional error messages in Substance saying that my tangents / bi-normals are invalid, as well.

doing a mesh > cleanup to make sure there isn't any nonmanifold geometry.

resetting fbx export settings and ensuring that normal data is exported properly.

the classic 'cube trick' (combine the mesh with a cube, delete the cube faces).

exporting as an obj and then re-importing into a fresh Maya scene, and then re-exporting to Substance.

and then re-doing all my custom hard edges and re-exporting to Substance

unlocking the normals in Maya, averaging them, setting them to face, etc.

Here are some things I've tried, unsuccessfully, to fix this: The mesh looks correct in both Maya and Unity, as well as in Blender.

My mesh has a lot of custom hard / smoothed edges, and when I bring it into Substance it basically softens all the edges, leaving it looking pretty gross.

and then re-calculates the normals itself. 'Mesh normals are invalid (some values are null) and will be recomputed' I'm encountering an issue I can't seem to find any documentation on: when I import certain meshes into Painter, it tells me: Hello! I'm experienced with Maya and other 3d programs but am fairly new to using Substance.

Adobe subtance 3d