octane 2.16 dark splotches on intersecting meshes with alpha

[PiotrAdamczyk]

Hi

I have one solid mesh with regular, shallow dents in it, and another one on top of it that has a honey comb grid alpha. In the bumps where these 2 meshes sometimes intersect some strange dark splotches appear. I tried every option i could tweak and i cant get rid of them. What are they and is there a way to fix it?

[aoktar]

You may try to increase specular depth. Or maybe a problem with ray epsilon. Hard to estimate from a small image.