Sorry eonite, of course I meant "density production " and not "density profile". I see how you can create the details with the function editor, but as I said the details produced with the detail amount slider don't look very good. I keep my fingers crossed for a feature that will allow us to modify exactly the shape of those details with the function editor. For example, by using a billow perlin noise or a voronoi node it would be much easier to achieve the shape of cumulus clouds.