3ds max 2016 mental ray render issue

[lowseb]

Hi all

 

Just two words about me, I am a game artist but I do occasionally some product renders (Maybe 3 or 4 per year)

Since the the 2012 version of 3dsmax I have a big issue with my mental ray render, since I use HDR image for light in fact

I have got some artefact in the reflection (some of my polygons are visibles in on line)

the is some images for explain.

I have made lot of google search about it , but got nothing.

I try to reproduce the issue with a simple scene

just a simple modified cylinder with a turbosmooth, lit by a MR sky portal and a skylight (in "use scene environnement" mode)

A background switcher in environnement, with a HDRI file in reflexion, solid color in background

we could see easily the issue

 

thanks for the help