Cloud Feature Request

[AP]

It would be nice to have a feature that allows the edges of the clouds to have a different noise flavour using another power fractal noise. Something like a fall-off modulator. If there is another way of achieving this as of current, how easy would it be?

Even a directional-only option would be nice where as the second noise can face west for example. I suppose the best way is using degrees.

[Dune]

I've sometimes thought about that as well, and done some experiments. Like fat clouds that whisp (?) out at the sides. The way I thought was to take the negative of the cloud fractal, and expand that with (a set of ) color adjusts, so you cover the edges of the initial clouds in a mask. Then use that to apply another fractal or redirect or warp or vector displacement. Maybe even use distribution shader(s) to restrict it certain heights.
But sure, one input and some sliders would be great.

[AP]

I think I might have found a possible solution using the Altitude Offset Function with some tweaking involved. I think I might have a billowy pattern with nice rigid wispy edges. I have to render it out to be certain.

[dandelO]

You can subtract a separate fractal noise from your density fractal edges this way. Create a suitably smaller scale fractal at the size/contrast/roughness etc, don't plug it in anywhere but set it to be masked/blended by the inverse of the density fractal. Next, create a new Merge Shader and plug the density fractal into the Input and the secondary fractal into Shader A. In the Merge Mode tab select to merge colour - Subtract(Input - A). Plug the merge shader into the Cloud Layer's Density Shader. Mix to A=0 will give you the untouched Density Fractal, the more Mix to A you add, the more 'eaten away' the edges of the Density Fractal will be. If you want a billowy subtraction, set the secondary noise flavour to Ridges, if you want a wispy subtraction, use Billows. Ridges are the inverse of billows so that's why you need the opposite noise to the edges you want on your cloud. The secondary fractal can be transformed any way you like. I set its Coverage Adjust to 1 so it eats all the edges, you could do whatever you like, though.

[dandelO]

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[AP]

Great, When I am done with my current render, I will try this out. Thanks!!!