How to fix tangent spaces on a mesh?

[Guest]

I was trying to make a hairstyle mashup for a character but one of the hair meshes I'm using has some broken tangents/bitangents on it and I can't figure out any way of fixing them. The result is a strange sort of glowing pattern. Does anyone know a way of fixing them?

 

[RomeoZero]

This is due to its overlapping vertices from below or above, hair meshes have 2 sided polygons - top layer and below it. This happens when you edit them by moving vertices on axis X\Y\Z,  especially with soft selection tab "on". Can be fixed with a soft selection tab [0.01] by manually adjusting top vertices higher from lower ones.    

[Guest]

23 minutes ago, romeozero said:

This is due to its overlapping vertices from below or above, hair meshes have 2 sided polygons - top layer and below it. This happens when you edit them by moving vertices on axis X\Y\Z,  especially with soft selection tab "on". Can be fixed with a soft selection tab [0.01] by manually adjusting top vertices higher from lower ones.    

It still persists after moving/removing those faces.

[RomeoZero]

 

Then that mesh was vertex welded in the first place, you will need to break those verts, select them and use "Break" in Edit Geometry tab. Move and align top vertices together and "weld" them back at [0,1] param, or align bottom verts first. It's a long process, make some tea ))