Hi there. While the sampling algorithms are already great and do the job perfectly in 99% cases, there some cases where one object is much more noisy than the other. Sometimes because of its material, sometimes we don't actually know why :) Instead of improving the sampling methods, is it possible to add a spinner value called "Sampling multiplier" in a CoronaMtl (or maybe in the object properties instead of material?) to upsample a specific object?
I'm adding an example of it - the image looks decent except of the black chair, which is pretty noisy.