variable noise threshold

Often, most of a scene looks great with low samples/high noise threshold, but certain material types (transmission, SSS) and bright areas of reflections need more than the rest of the scene.

It would be great if you could set a lower noise threshold just for those problematic areas to avoid spending unnecessary render time on the other parts of the render.

In the samples settings, instead of having a single noise threshold input, there could be a min noise threshold and a max noise threshold.

In the passes and the material options, there could be a zero to one slider named 'quality'. Zero would mean use the min noise threshold, one would mean use the max noise threshold. If the material quality and the pass to which that material belongs differ, for example the diffuse pass and a SSS material, then the material setting would be used for the pixels where the material is contributing.

This would allow users to find the best balance, and then just change the min/max noise thresholds in one place when they want to switch between draft renders and final renders.