Attached Link: http://excalibur.renderosity.com/mod/gallery/index.php?image_id=1300982

I guess I have two possible answers for this that may work, but both depend on your orientation of camera, and how bubbly we're talking here.

One option I forsee is if you're talking columns of bubbles, make a terrain column then wrap a "rain effect" on it.  From a distance, the blobs of rain may appear as bubbles.

But if you're inside the bubbles, and you want little fizzy ones, I'm thinking using a snow or "starfield texture, or take a volume sphere around the camera where the density is low, and the quality is too.  That gives a lot of speckled spots.  I do something similar for ocean spray. (as found in my latest picture... shameless plug)

Ooh, idea for a third way of potentially handling bubbles.  If you're looking for "scuba like" respirations, create a cloud underwater by using a rock terrain, stretch it out a little, and look for a surface cloud texture like "Jetstream" that has a high reflectivity, and if you can play with it a little for a speckly/lumpy bump pattern that you can crank, that may do the trick.

Just some thoughts, now I'm going to have to experiment with them.  Now ya done it.  Ya got me thinkin, Fran... and that's never healthy for me. ;c)

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