'Smoothing' is not making geometry totally smooth


I have built this DNA Helix model in Blender, used the ‘array’ and ‘deform’ (for the twist) modifiers and set the mesh to smooth. However the main struts seem to show grooves in the viewport and unsurprisingly when I hit render. They are very fine ‘grooves’ but when rendered at a big resolution they are of course more noticeable.

Does anybody have any idea how to fix this slight problem? The model itself is quite high poly. The polys however, are needed to give the Helix a non angular shape when the mods are applied.

Any ideas? Could it be a lighting issue not a shading issue?

Thanks in advance



The problem might be the topology or edge loop flow. It seems the faces aren’t nice square shapes, but more like diamond shapes. Creates nasty twists. And with the high density this gets pretty noticeable

Depending on the overall object, you could probably use a lot less geometry for it and reduce the twisting.

If that’s outer spiral which gets stripy, then i would think it’s pretty hard to bend that long and narrow stripes. What if you increase spiral’s cross section count and lesser diameter resolution, if that’s made out of bezier? Subdiv would have less to smooth after. As to the diamond shapes - i see them coming from X ray enabled, just see through effect, am i right?

For this sort of thing, I would suggest trying to use curves with a circular bevel object.

For quick fix, I try Edge Split Modifier to see if that will work.

I’ve got a similar problem. I played around with the Boolean modifier today, the mesh looks normal with flat shading but its being messed up by the smooth shading. Normals are checked. The weird thing is, that this also occurs on a simple cylinder … wonder what it is, it also occurs with previous versions of Blender but it never happened since a few weeks ago. Might be a problem with graphics card maybe …

Have you tried adding an Edge Split modifier? It should fix the problem.