Unreal Engine 5 Tangent Space and Triangulation Problem

nattemre

My problem is that I've asked questions about triangulation and game modeling on the forum before and learned a lot, but I've actually encountered an error I can't solve. I've configured my model's UV, Normal, and topology correctly. But I'm experiencing stretching in my models. I'm investigating the cause and how to resolve it. I'd be very grateful if you could explain this technical issue to me, my friends.

poopipe

Triangulate the mesh before export. This is a Uv Interpolation artefact - most likely cause by the invisible edge flipping 

nattemre

poopipe said:

Triangulate the mesh before export. This is a Uv Interpolation artefact - most likely cause by the invisible edge flipping 

Thank you for answer my friend but i don't know edge flipping. What is the edge flipping  ?

ZacD

There's 2 ways to split a quad into a triangle. If 2 programs triangulate the mesh differently it can cause issues, particularly with normal maps. It's expected to triangulate meshes after UVing and before baking and exporting.

pior

Well, this could also simply be incorrectly laid UVs, or, UE displaying the texture as mapped to an incorrect channel receiving an automatic unwrap.

@nattemre : simply provide your source file (as exported from your scene/as imported into the engine) for people to have a look, otherwise any advice would be a mere guess.

nattemre

pior said:

Well, this could also simply be incorrectly laid UVs, or, UE displaying the texture as mapped to an incorrect channel receiving an automatic unwrap.

@nattemre : simply provide your source file (as exported from your scene/as imported into the engine) for people to have a look, otherwise any advice would be a mere guess.

Yesterday, after a lot of effort, I discovered that the problem was caused by the UV, as you said. I hadn't divided the UV there, and it had tried to bend itself from the inside out. When I fixed the UV, it looked great. Thank you everyone for your help.