+ # Check if tangent vectors are needed
+ if mesh.tangent_vecs=='NO':
+ self.tangent_vecs = False
+ elif mesh.tangent_vecs=='YES':
+ self.tangent_vecs = True
+ elif mesh.tangent_vecs=='AUTO':
+ from .material import Material
+ self.tangent_vecs = False
+ for m in self.materials:
+ mat = Material(m)
+ if mat.type=="pbr":
+ normal_prop = next((p for p in mat.properties if p.tex_keyword=="normal_map"), None)
+ if normal_prop and normal_prop.texture:
+ self.tangent_vecs = True
+