Hi evereyone and many thanks to read and help me ,so i have a problem i want to make some Ink like in HarryPotter film (see the picture) ,i have a sphere emtiing paricles this particles i will render like points and millons or particles looks like a ink in smoke container,td advect by fluid,when i make the render yes its looks like ink,my problem its the behavior of the
particles,they expand so much and the effect needs be stoped i want stay together like the travel along a way and nor expand
I tried a chargue,with interact but nothing dont work,please any ideas how i can control the particles??

sorry for my english i can read it but at time to write its other thing

well….not so easy to set up a convincing ink effect…
try to have only one object to emit both smoke and particles, keep a low res smoke container and bring some dynamics here before advecting particles to it…maybe a wind for noise generation and a gravity, then think if it's better have a constant rate birth per frame or have a massive volume birth,as a real drop of ink is a volume falling in another liquid/volume and is not generated each frame that it penetrates.Then the behaviour becomes an art matter, there are some tutorials on the net with different approaches for other 3d apps…so look at different ink effects here seems to be a math pattern : http://www.youtube.com/watch?v=VPBdsIWyUZk [youtube.com] — and here seems more a cigarette smoke : http://www.youtube.com/watch?v=tHMUTl7sfvQ [youtube.com] — maybe the weight of the liquid and the speed of fall make the difference in random motions.

Also Peter Quint on vimeo has a good tutorial for a ink like effect, check rendering million of particles.

Thank you blonde i will try follow the examples and the advice and i will tell you,now im going to workin thist moment,i hope you will see the result soon