The new "v3" cloud shading model is much more realistic in most cases. But we left the older "v2" model in both because it renders faster and in case some people prefer it for some situations (and for backward compatibility). We will continue to improve the v3 model and its controllability. But if you prefer results from v2, just use v2. v3 should be able to get better results than v2 in almost every case, but of course the render time will be higher (and you will have to use different settings and techniques because they work differently). Better results don't magically come at the same render time in most cases.
But remember, v3 clouds are the default in TG4, Defer Atmo is *enabled by default* in TG4 (and there's a reason for this), and finally, there are 2 separate major sources of noise for skies: atmosphere, and clouds. You want to try to figure out where your noise is coming from and then *only* increase samples/quality there. Do not uniformly increase atmo samples and cloud quality unless you're sure both are a source of noise. In the case of the first images in this thread I would guess the main source of noise is *clouds* and would suggest Defer Atmo, AA 4 or 6, and cloud quality 1 to start, with atmo samples at 16.
- Oshyan
