Particle random creation time?

I’ve been through a few particle tutorials on the tube and I can do almost what I want. However I can’t find the answer to one thing which I would have though would be pretty easy to find and I’m sure I’m missing something simple.

Say I want 10 particles created from frame 100 to 200, and I setup the forces and all that stuff so I get just the look I want, but I want the particles “created” at random intervals, so I don’t get a particle every 10 frames.

How is this achieved? I can randomize just about everything, but can’t find this setting.


Yeah, that’s a big question I’ve had as well. There doesn’t seem to be an easy way to do it. If anyone has a solution I’d love to hear it as well! :slight_smile:

Add a particle texture to influence the time value. When you add a particle system you will them have the option to add a particle texture in the texture settings
For the texture try the various procedural ones with some noise (like Wood with Band Noise enabled and increased turbulence)


untitled.blend (110 KB)

Ah yes, time mode textures! I’ve used the method a bit before I just feel its unfortunately there’s not a more straight forward way like a particle per second value that can be keyed. Using textures can be useful but a bit in-exact. (Also, node-based textures are a no go with particle systems it seems). Sorry to hijack your thread OP, but its a question I’ve been struggling with to find a straight forward answer to for some time. Also, thanks for the example file Richard!

I always wanted to be able to Keyframe, and simulate, (producing Keyframes) that can be deleted or overridden.

Particles behave according to physics until they all almost reach a point, where keyframes take over, each particle flying into place to do whatever. (keyed by hand at the end)

No worries about hijacking the thread, the more input the better.

I’ll look into the texture thing, but it doesn’t sound to be quite what I’m after. If you imagine the fireflies from a jet engine, you tend to get a big blast to start with, then a random fairly steady stream. Two particle systems on the one object manages this, but the stream is too steady, you really want 2 popping out one second, then 5 the next, then 1 the next etc. You can kind of simulate this with multiple overlapping systems, but you never get around the rhythmic look of the animation.

I can’t help thinking it would be pretty easy to pop in a ‘jiggle’ variable.

You could create a small container for them to collide inside and have an opening which controls overall how many get out, and you would get random emission with a master control for overall density.

Simple colliderbox.blend on dropbox