interior light mode > cloudy surface

[janm]

I did quite a lot of tests during the last days finding the right settings for an interior scene, but I am not satisfied with the result. For the demo picture I rendered with 64 Samples but if I render with higher samples the walls and ceiling are still cloudy. Can anybody help?
I put a light bump map to the wall and ceiling texture.
Outside every window I placed a surface with Area-Light texture not visible to camera, reflection and shadow.

[DMerz III]

As a best practice, I would up sampling rate for anything using Interior mode. The tradeoff is that you will usually sample at a faster rate, but you will need slightly more samples to get a really accurate and clean result. My understanding is that Interior mode has a denoiser built into the calculation and that will lead to some of that 'splotchy' cloudy look you're getting. It will go away with more samples.

If you're thinking, 'oh...I'll just use product mode then, and keep it at 64' you're going to discover that won't look right either. Especially for this scene, interior mode is the way to go.

[janm]

>As a best practice, I would up sampling rate for anything using Interior mode.

I really love the speed and quality of Keyshot in product mode but I am not so happy with interior mode especially with white and smooth walls.