I’d like to investigate the noise distribution in final renders, in order to more effectively use Cycles’ adaptive sampling feature. The ultimate goal, if something useful does comes up, would be to develop tools to help optimize the sampling parameters.
I tried searching Cycles’ source code to see how it is calculated, but couldn’t find it. Does anyone know which algorithm is used to assess the render’s noise levels (to enforce the Noise Threshold, for example)? Alternatively, could someone point me to the bit of code in which it is calculated?