I think calculating an image and after some passes compare with the last one will always left noise.
I think it is better this way: Let cook the render for a number of samples defined for the user. And then look for every pixel their neighbours and calculate the difference and sum all the differences and you have a “weight” of differences with the neighbours for every pixel.
Brecht says that this (my) method will fail
I don’t belive that - i demonstrated that it is really possible to detect NOISE
3 samples 100+99+101 = 100 (average value)
3 samples 50+140+110 = 100 (average value)
as you see 1. pixel is stable (low variance)
and 2. pixel is non-stable (high variance)
cycles do not detect that - it sum only every value
and this is the key!
So i am working on it now and study cycles-code - i understand some parts of it.
I’ve seen this at the mailing list:
The short film and the images are looking very good. Maybe this could be transferred to Cycles?
this works bit different - but look interesting