Controlling random emission of particles

[darthBaldus]

Hi, any help with this would be awesome.

I can randomly emit particles over time with an expression. I can adjust the frequency and offset the values, but is there a way to control or limit how long each random emission lasts? 

Imagine a sputtering hose, but each stream that shoots out - can only shoot out for 5-10 frames. Much longer than that and it all joins together to form a solid looking stream. I need random blasts, that are limited to 5-10 frames each.

Thanks!

Andy

[kungFu]

You can delete particles before they get into the sim., for example, add  color to the points with a point vop (something like animated anti-aliased noise), then delete the particles that are red.

Alternatively you can switch it to use "all points" and then in the Impulse Activation field use some thing like this

pulse($F, 20,24) ||pulse($F, 30,38)

so pulse turns it on for the duration, and then the OR operator. you can add as many pulse expressions as you like this way. You can add to that to randomize the length of the randomness

pulse($F, 20,24) ||pulse($F, 30, int( fit(rand($OBJ),0,1, 33,38)) )

so this will return one burst frames 20-24, and another from 30 to somewhere between 33 and 38.

The noise pattern run over the color will produce a nice result too.

 

sorry those should be $FF not $F in the POPNET

kf

Edited May 31, 2016 by kungFu
incorrect