Black Line 'Scars' where Edges intercept (Topology)

Hello all,

I’m creating a cave structure in Blender as a background for my webcomic but I’ve come across a problem, I’ve created this cave mainly by extruding and merging edges though at the start I began the model as a box which I deleted faces which may have caused an issue.

No Issue with the other side.

I’ve ended up with strange black ‘scarring’ along some of the edges of the topology. They don’t seem to be a gap isssue as I can move the edges with the black edges around no problem (no holes appearing). Is there something else going on?

Cheers, and thanks for any help!

Looks like the normals, try to select all in edit mode and mesh-normals-recalculate outside

Thanks so much! That did the trick! :slight_smile: