There is a problem with a fill length mirror from floor to the celeing - on the celeing appears strange grey areas. I tried to change material settings but nothing worked. Please help to solve this problem.
I think it is the contrast of the wall reflections and the mirror (lack of reflection). Could your wall color be too bright white? It’s getting full frontal light and perhaps that’s bleeding too much onto the ceiling.
Whereas there would be no white reflection from the mirror. Maybe adjusting the wall color, the reflectivity of the ceiling material and running it longer might help.
No, its not helping. Celeing is RGB 220 - 220 - 220 and walls are RGB 234 - 226 - 215. i tried to change walls and celeing to the darker color - also not helping. And I turned off reflections at all in both material - still same problem occurs.
Regarding longer rendering - Last render lasted 4 hours and
nothing changed. still looked the same.