Flicking/Artifacts in Eevee and Cycles on Filled Curve

It doesn’t look like z-fighting. It behaves fine in solid mode. Mesh seems fine on paper, all faces and verts accounted for.


In Eevee it creates a strange flickering while moving viewport, only noticeable if wireframe or face orientation is on.

Here in Cycles, it creates some rather strange outcomes, varying even between instance to instance. No flicking, just… whatever this is…

I’m utterly confused.

Are the artifacts in the Cycles image the black parts? If yes, that’s interesting, because that’s usually the sign of overlapping faces. Eevee is less sensitive to it, so it makes sense you wouldn’t see it.

Indeed. But in Cycles, it doesn’t flicker… What you see there is stable.

I have individually looked at all 38 faces on that mesh separately. It all checks out.

Does it happen with any material?

Is the object very small or very large? If it is, you may need to adjust the clip start / clip end settings to reflect the scale of the scene.

Not doing any weird resizing. It’s a simple diffuse material. If I apply other materials, the same sections are blacked out.

Have you tried applying the modifier so you can look at the mesh?

Does your setup manipulate normals at any point or add custom normal data?

I should have done that. It is in fact z-fighting. A duplicate is occurring somehow. But that’s outside the scope of this thread. Thank you friend, you helped.