looping/repeating particles

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  08 August 2006
looping/repeating particles

Hi folks, I have what must be a simple effect to achieve but I am having a brain lock trying to think how to do this.

What I want is a setup where I have a particle emit for x amount of particles and then stop, and then the start again so there would be a gap in the flow.

Imagine a machine gun effect. Pull the trigger and one particle emits after another along a straight line or path follow or find target object. Release the trigger and the particles that have been emitter will continiue along their way but no new ones are generated. Pull the trigger again and more particles start to emit along the same procedure following the first ones but obviusly there is a gap between the first burst and the new one.

I know I can do this with multiple PFsources but what if I want this to repeat itself indefinitely? Do I have to recreate new PFsources for each burst of particles?

Say I want a particle to emit 10 particles along a straight line then stop for 10 seconds and then start the same thing over again. Do I have to create 10 PFsources for this?

Max 7 btw.

Any help on this would be awesome as I am sure its pretty easy and I am just being a turnip today!
  08 August 2006

ok, I figured this out. I was having a pretty crazy day yesterday. The easy and totally obvious solution is to animate the 'rate' in the birth operand.

Pretty easy when you know how.

Back to being a turnip for the rest of the day...
  09 September 2006
hi there, i'm trying to achieve the same result and have my particle birth create a sort of pulsing effect. i've tried animating the birth rate converting it to a bezier curve but this doesnt affect the emitting of the particles at all, even if the rate is 0 i still have particles emitted. maybe i'm doing it wrong. could you tell me what you've done to get it to work please?
  09 September 2006
i'm going to answer Usil's original question but this should help you too redskin106.

One way i've found to add pauses or breaks in particles being emitted is to hav a separate event that simply holds the particle that is emitting others for a set time.

eg. make a new flow, lets birth say 1 particle that will be emitting others. use a position object or icon to place is where you need it. then use a send out test to put the particle into a new event. Lets call the new event "ParticleEmitter" the reason we do this is we cannot 'loop' events back into a an event with a birth operator.

In the "ParticleEmitter" event, create a spawn test and set the rate to whatever you need. then create an age test and set it to 'event age' is greater than, lets say 30 frames. Link the spawn test to a new event with just a display operator for now, you can add operators to fit your needs later. lets call this new event "Bullets". Now link the age test to another new event containting another age test. Lets call it "EmitterHold".

Set the age test in the "EmitterHold" event to by 'event age' and is greater than lets say 10 frames. Now link the age test back to your "ParticleEmitter" Event and thats it!

so basically you have your particle that is spawning your bullets in the 'ParticleEmitter" event. After 30 frames of spawning bullets it goes off to the "Hold" event where it does nothing for 10 frames. Then after those 10 frames are up, the Emitting particle moves back into the ParticleEmitter event and starts spawning particles into the "Bullet" event again.

this is a lot more procedural than animating the rate and also allows you to very simply add variation to each of the age test events so the effect is not so constant.

Hope this helps

  09 September 2006
just wanted to thank you for this... now i can have my looping particle system...
  09 September 2006
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