I have a model which its sofa's some faces are back face faced front, and in Backface culling mode these faces are invisible.
How I can change these faces orientation? I have tried Mesh Display Reverse, these faces are become visible in Backface Culling mode, and I have confirmed the normal using Polygon->Face Normals is correct; But seems the normals used for lighting calculation is not reversed cause in lighting mode it's not lited.

How I can fix this? Thanks in advance.


I think I have figured the point out, what's differences between user normal and face normal that
on Reverse Normals Options dialog?