mesh has some nearly zero tangents/bi-normals

Annotation 2020-05-14 190707.jpg

anyone knows how to fix this. i made a search, but couldn’t find anything really helpful. i’m pretty sure this is UV mapping related. it’s not a model i’ve made myself, but that i purchased. the thing is it’s a 90k polys mesh. so if i knew where to search, even a small clue it would definitely help. as i wouldn’t have to search ‘poly by poly’. I’m on Blender

I’m having this same issue and can’t find any information on it. Any guidance would be appreciated.

IIRC, the FBX Importer tries to calculate Tangent and Binormal information from UV’s unless you explicitly import them. If the object is poorly UV’d or has no/malformed UV info I can see this being a problem.

I don’t know about Blender, but in 3DS Max there is an option to “Export Tangents and Bi-Normals” with the FBX. You can then change the import option from ‘Calculate Normals’ to “Import Normals and Tangents”.

Blender probably has a similar export option I would imagine.