Black lines with overlapping objects

Hey all,

I’ve got a question about this model I got. In it are a couple of objects that overlap each other. When I render them I can see some clear black dots/lines where they overlap.

Here’s what I’m talking about:

Does anybody know how to fix that?


I’m not 100% sure, but I believe blender has problems trying to render to objects that exist in the same physical place or more specifically where the vertexes/faces co-exist as it has no way of knowing which should be “on top.”

I noticed this when I duplicated and split part of a mesh to do some testing and accidently duplicated it twice leaving the first copy in the same place as the original.

Yeah I know about that, but I’m abosulety sure that isn’t the problem. I’ve removed all double vertices (in fact the light grey thing is just a normal uv sphere and the dark grey thing is a cube with some subdivision) and I’ve made sure that I didn’t accidentally duplicated one of the objects.

I’ll try to see if I can reproduce it in more simple scene.


Well I’ve copied the blender file and I’ve started removing all settings I’ve set and appertally I switched on the transparency on both materials. Can’t remember why I would want to do that, but that caused the little black line.

Problem solved.