The most obvious way is to make a fluid using a particle system where each particle is a metaball, and then making air particles that are negative metaballs.
But that would require a very high metaball resolution for fine bubbles.
Hi! Metaballs works, but they are quite computational expensive. Instead of metaballs i just used normal icospheres and placed a plane on the water level to kill them once they reach it.
-here’s the result:
I would do something very similar to thankz, but in my mind you should flip the normals on the icosphere. Otherwise what you have is like glass marbles in the water.