I have a big problem that I can't get rid of very visible artifacts in my interior scene although I am already using high render settings. (see screenshots below). It's a scene of a big room with some windows. I am using Vray's sun system. Therefore everything works. To get better shadows I also have rectangular lights set as light portals outside of every window.
I am also using the physical camera with a withbalance color.
Indirect Illumination methodes are Irridiance Map + Light Cache (both on higher settings.)
Nevertheless the rendering comes out pretty un-smooth. How do I increase the quality? Do the settings of the light when set to light portal have any effect on the scene? Or is this only a matter of render settings? Do I need to increase a parameter with the sun?
For reference please see attached pictures (render output, sun settings, vray render settings)
Please help. Thank you so much.