Modeling issue?

Dear all,

i started to teach myself blender with Youtube and books. I created the attached cylinder with 8 vertices and then i extruded and scaled to get my shape, but in the smooth render mode I see this “error”, but I mean if I look at the wireframe it looks good.

Does somebody know what went wrong and give me an advise or is this a graphic error?


Looks like you have overlapping faces, you may have extruded the cylinder similarly (or in the opposite direction) to this:

steps 1 to 4 ok, then for mistake you extruded and moved “5” in the exact position of “2” .
A solution would be to delete all the vertices/ edges that are forming “5”.

Looks like z-fighting. Is this only in the GL view or does it show up in render too? If it shows up only in preview, then near and far clipping settings may help. If it’s also in a render, you’ll have to adjust the model so there’s no overlapping planes.

Yeah. Judging from what look like flipped normals and the “ripping” effect, I’d say z-fighting. If there are faces sharing the same 3d space, it’ll look deceptively fine in wireframe view.

Try selecting all and hit remove doubles, sometimes can resolve this issue.