Thank you for the kind help!

@m_adam: The plug-in you have linked is very useful. I could fix some problems with the "Select polygons by normal direction" function.

Working with badly constructed meshes is no fun job either way.

Kind regards,
Julien.

Hello,

is there a way to flip all the face normals for selected polygons in one direction, especially in python?
The intended purpose is to fix a completly "broken" mesh to correct the background culling for Unity.

Thanks in advance!

Julien

Example:
All stair polygons should face upwards.
Tried align normals and optimize commands, but they did not work with this mesh.