I have been modelling a wheel-like object. I started with a torus. Stretched it out a little. Then added a mirror modifier to work on it with symmetry.
And all was looking good until when I noticed on the mirrored side a big block of black filling in the wheel around the central hub.
I thought maybe I need to add some loop cuts to square up the faces a little more.
These first two images are from the object with the mirror modifier.
I thought maybe it was the modifier with a bug so I duplicated the object and applied the modifier on the second version. I still have the same black banding!
It looks similar to overlapping faces along the same plane.
But it only happens on this one side. The "mirrored" side, both before and after applying the mirror modifier.
I've checked the vertices, edges, and faces, in case I'd managed to double them up somehow.
Deleting the mirror modifier and creating it again didn't help.
It would be nice to understand what I managed to do wrong.
I expect my next step is to drop the modifier and just duplicate the side I have and weld them together to form the full object again.
NOTE: There are no materials yet defined or applied to the object as yet.
I'm using Blender 3.1.2 on Windows 11
Here's a link to the blend file... https://www.dropbox.com/sh/tlfxrho8gf8fr77/AADZqKphYxavNtAl8izZzPCoa?dl=0