Floats

– You need three Objects:

– A Fluid object Type: Domain
– A Fluid object Type: Fluid (inside the Domain)
– A Fluid object Type: Particle (no matter where)

– Set the same cache directory for the ‘Fluid: Domain’ object and the ‘Fluid: Particle’ object
– Check ‘Floats’ from the Settings tab of the ‘Fluid: Particle’ object
– Bake!

– In this example the Floats particles are coloured in light blue
– Note how the presence of Floats particles is not only a visual effects but also affects the simulation (as you can see from the poster image).

– In this example I rendered (video on the right) only the Floats particles:

Blender Fluid Particle Floats