I’m trying to figure this out.
I have a box, then 1 mm (or 0.001 BU) below it I have a plane, but no sub-divisions, or anything, just a flat plane. I have three lights, and a camera.
I think the face under the object is not rendering correctly, but I cannot understand why.
1 flat surface, (must be composed of 4 triangles.)
Directly around the perimeter of the box, it appears that the plan is not rendering correctly. Maybe the two faces directly under the box are not rendering correctly, would this be some type of culling, to render on the visible faces?
Some kind of issue with the normals. They render fine, when the objects are not close to each other.
I’m posted a few renders here: