Black splotches when reflecting with final gather


i´m having trouble with mental ray and FG.
i´m showing an example scene, but happens every time i use some raytraced reflection and FG.
when i lit the scene just with hdri or skylight i got these black dots witch appear to be something related to FG samples.
the material from the sphere is a MR shader, where i have tryed lume metal, reflect base, and raytraced (3ds) on the surface slot.
here´s a test

i have tried controlling the photons, but that doesn´t seems to work.
I remember seing something similar here in cgtalk, but i wasn´t able to find it.
For more information, here´s another render with smaller radius in fg and another filter nº:

i can blur the spots by setting bigger radius but thats unaccurate:

could anyone have a clue on what´s happening or what settings am i overlooking?
thanks in advance.


i figured out which setting was messing all up.
apparently when i put an hdri in the environment slot of the MR material (environment 3dsmax) the dots start to appear. everything works fine if there isn´t a mep there.
i can put the hdri in the global environment for reflection, but is there a way to override it within my MR material? just when i though i started to understand MR…


This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.