When I operate on my mesh, black spots and glitches appear. All the normals are aligned correctly and the UV is clean with everything in the right place. Here is an example of what happens when I seperate some faces; enter image description here

Notice the triangular blotches on the edges.

Here is an example of subdivision on the mesh;

enter image description here

And again, similar corruption occurs when I delete doubles. I have no idea what could be causing this. Can anybody help please?

  • $\begingroup$ Interesting. If I clear custom split normals data, then subdivide, then press add custom split normals again, the effect goes away. I've still no idea what's going on. I shall have to read the docs on split normals (whatever they are). $\endgroup$
    – Rudy
    Commented Mar 5, 2018 at 11:29

1 Answer 1


All right I don't know. I guess the problem bred from the software I used to extract the model (Ninjaripper). It created a weird data layer of normals information (sharp-edge, smooth-face, etc) which doesn't show up in the viewport edit. It makes precious little sense to me, and the man-pages aren't very clear on the subject at all.

The fix as I mentioned above is to remove the data layer before editing, then replace it again afterwards.

Run it up the flagpole...


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