Intersect underlying as cloud density?

[Hannes]

Is it possible to use intersect underlying (favour rises) of an existing shader as density shader for clouds?

[Dune]

You want foamclouds to sprout from wavetops.... it's easiest to just try it. Perhaps you need a total black surface before adding the mask, so (black) surface layer dangling somewhere, add mask as child, perhaps stretch that in Y and use as cloud mask. You should also use the altitude offset method in the clouds, perhaps.
But I don't know if it would work.

[Hannes]

You want foamclouds to sprout from wavetops.... it's easiest to just try it...

Right! And of course I did try!
But it didn't work so far. I thought maybe there is some sort of function that reads the b/w output of the intersect underlying "result"?!
However thanks, Ulco!!!

[Dune]

Perhaps feed it through a compute terrain, small patch, then a displacement to scalar and an additional color adjust... (?) then use as mask... I know, it takes a lot of thinking and T&E 

[Hannes]

Thanks a lot, Ulco!
I'm not at home atm, but I'll try your suggestions as soon as possible!

[Tangled-Universe]

I'd try a displacement shader to scalar node from the water node to convert the wave 'heightfield' to a greyscale scalar value.
Then using a colour adjust shader you can brighten the tops of the wave.
From there on you try different things:
1) create a cloud layer and mask the cloud fractal with the colour adjusted scalar from displacement.
2) create a cloud layer and use the scalar from displacement to drive the altitude offset function (difficult!)
3) combine 1 and 2

[Kadri]

Different then using directly Terragen of course, but Blender could be used for outputting it water object files too.
If Max (as you already use it Hannes) can that too i would rather use that files then Terragen only.
Although haven't tried that method. Not sure about the cons and pros.