[Kabe]

During a render I would like to set where M~R should shoot more rays.

Quite often most of the image is already clear after 2-3 hours, and still the
rays are evenly distributed. I would like to mark the problem areas that
should get (much) higher attention. Around the marked areas there's the
need for a transition zone (probably Gaussian distributed) to avoid artifacts.

Well, it might introduce a bit of a bias, however the benefit in real rendertimes
could be so massive, that I would sometimes really rather take it.

What do you think?

Kabe

[JDHill]

I agree, Kabe...and bias for me in this case is no problem, as it is:

1) optional
2) directly user-defined
3) non-permanent (invert selection)

I would suggest a lasso-type selection of multiple areas, with a user-defined blend-radius per selection.

~JD

[Kabe]

I prefer a brush-like tool, as dealing with lasso selections is IMO a bit more
difficult to understand and to code as well

Kabe

[Fernando Tella]

Great!