Black polys when rendering

I’m getting these weird black polygons when rendering and I’m not sure why? Also, when I rotate the camera around, they grow and decrease in areas. From what I’ve read, it sounds like it may be a rendering setting that could be changed; ray bias? I can’t find that parameter though.

The first image is without the glass top, which is fine, but when the glass top is visible, I get the black polys.

Anyway, always appreciate any help​

Most likely overlapping or coplanar faces, or possibly doubled faces if the mesh is a CAD import.
Seondary ray bias is within the attached tab…might help if you can’t fix the faces first :slight_smile:

Hi, thanks for posting. Could also be a dirt map or something material related. You could send us the scene for review. Please do that here or by using our support contact form.