A while back S68 put up a metaball animation using negative metaballs.
https://blenderartists.org/forum/viewtopic.php?t=14058
This is a variation I did , thanks for the inspiration.
And here is the link to the animation (right click and save target as)
http://hstrial-jgray1.homestead.com/files/metaboom6Divx.avi
Divx 1.15 megs.
Paradox
huh, looks disgusting, the yellowred ball… it’s like… something from inside the human body that I don’t want to know …
can you make the edges more round?
.b
cool, the breakdown reminds me of “the langoliers”
Roel
Re: the edges yes, I believe you can. I think it has something to do with wire size which would also improve the edges I believe when the balls merge. I did this when S68 posted his version but never put it up. If I do an updated version I’ll repost.
Thanks for the comments basse, glad it caused a reaction even disgust. 
Paradox
Thanks goofster, you must have replied when I was posting my reply to basse, the langoliers was interesting. Yes the effect is kind of sci-fi-ish.
metaballs create some interesting effects. Glad I found out about negative metaballs. With this technique you could do something like when someone gets shot in space and the splatter floats around the room.
Paradox
Very nice
Looks like ‘evaporating’
To have smoother edge you must decrease metaball resolution… beware of CPU time then!
Stefano
Thanks S68 for the tip on metaball resolution. I used 3 metaballs inside like yours but one I left as regular metaball instead of negative and added some random force, which is how they come out the back. Just a fun thing but I can see some use for it in some future project.
Paradox
reminds me of my stomach after a night of heavy drinking