Noob problem

Sorry- new to modelling… Why does this happen? Guessing a normals issue but recalculate doesn’t fix, Something more fundamental in my modelling approach??

Probably a duplicate geometry or a duplicate object.

sample blend please, there are numerous reason it could be like that

Thanks- blend file here:

It looks like bug to me let wait for more confirmations since I have a very bad history about reporting bug :wink:

You got me, I have no idea now. I thought at first it was because you have a duplicate in the same space, and I also thought maybe you had normals pointing wrong direction, but now I am wondering if it is just that the scale is so big. Strange thing is if I switch to Blender Render and render preview window draw mode, then I don’t get the issue at all.

it is not a bug, but the geometry is so crooky, there are quads that are not flat, namely at the parts that render so odd… you can fix that by selecting everything in vertex mode, and apply a few smooths. then reselct the rims and make the sharp again by pushing them into the correct direction.