To clarify why this is important, it's good to get an understand on what parts of the image have reached a certain noise level. For now, I know that a certain noise level in the image is good enough for my needs, but I can't really see if that area has actually reached the set noise level or not. Only way I can know is to zoom in very close and see if some pixels shift, as if they are being sampled. If I could have a pass indicating with, for example, a green color that "this area has now reached your desired noise level", I can determine exactly what noise level I need and therefore not waste a single minute more of rendering time than absolutely necessary.
To clarify why this is important, it's good to get an understand on what parts of the image have reached a certain noise level. For now, I know that a certain noise level in the image is good enough for my needs, but I can't really see if that area has actually reached the set noise level or not. Only way I can know is to zoom in very close and see if some pixels shift, as if they are being sampled. If I could have a pass indicating with, for example, a green color that "this area has now reached your desired noise level", I can determine exactly what noise level I need and therefore not waste a single minute more of rendering time than absolutely necessary.