I know this might sound odd, but Vray doesn’t seem to render open polygons very well.
By open polygons I mean objects that are not completely closed. For example, if I create a box, but delete one side of the box, light seems to come through that hole in the box, which is natural, but let’s say that another object is covering that open end. Vray still renders light coming through that open box.
Is there some way to fix this? Or is this perfectly normal and I’m an idiot? Don’t answer that last part.