Looks like I'm getting closer!
I've started the whole thing up again with Particles... (pretty stubborn, am I not? ;-)p
I've managed to keep the particles emitted from the can's surface stucked on the surface itself (1/2 way), simply setting to zero the "normals velocity" value in the "ParticleShape" tab. And by raising the "Threshold" value I've even gotten the closest drops to join together as a single shaped-like ones.
As for the randomness of each drop's size, I solved the problem with a pretty simple expression, adding the "radiusPP" field in the same tab and editing the field like this:
particleShape1.radiusPP = rand (0.05, 0.5);
The result is a way faster rendering time (even with "visible in reflections/refraction" enabled) and a more natural look of the drops' positioning.
The problem I now have is that, even if the particles seems to be ditributed randomly - but uniformly - around the can (in the persp panel), once I render them in MR, they looks as if they're aligned along the Vs of the can's UVs. So that I have areas filled in vertical direction by drops, alternated by empty ones.
I'm planning to solve the problem by painting a texturemap directly on the can's surface with the painter tool, or appliyng a distorted Ramp to the particles and make'em "emit from black" parts of the texture.
I think this way I can obtain a better control on the areas I want to be filled with random drops, areas I want the drop to be less visible (by setting the color to gray instead of black) and force the drop to be emitted from areas which are now... "dropless".
What do U think?
Am I followin' the right path?
Oh... Another doubt;
What if I wanted to insert a - say - "Turbulence" field to randomize the particles drops around the can? Is there a way to keep on having each drop *stucked* 1/2 way on the can?
(If I do it right now, the drops get floating away from it).
If you can keep your head when all about you are losing theirs,
it's just possible you haven't grasped the situation.