View Full Version : Particle birth rate?

08-08-2003, 08:30 AM

I have a slight problem with mi particles. As far as understand it, if you set a particle birth rate to 1 then a particle should be born every 1 second. Is this correct?
I have a scene where I want a particle to be born every 2 seconds & it's life time another 2 seconds while it's doing its thing. However i'm getting random birth rate results. :( Can anyone tell me why this is?


08-08-2003, 11:11 AM
Not, sure, i never figured that one out my self aswell...
PFX seems to be very inaccurate in its particle emition (a bug maybe?....nah..in Lightwave?...kidding...)

Sorry, can't help you there, seems like you'll have to find another means to this end...

08-08-2003, 11:23 AM
Damn dirty apes!

You'd think they'd have ironed out a bug like this by now. Kinda puts me up sh** creak now :( but i guess as you say, i'll have to find another way.


08-08-2003, 02:47 PM
Not sure if its practical but u could just use a null or a 1 point polygon and animate that, using desolved to fade it out, then every second or what ever just move it back to the start.


08-08-2003, 03:48 PM
I had the same problem trying to do machine gun tracer bullets. Ended up animating an individual object, then cloning it and offsetting the keys.

08-08-2003, 04:53 PM
There are a couple of ways to get particles to emitt at regular intervals or at user specified frames.

The most forward way of doing it is by setting "Generate by" to "Frame" and creating a stepped envelope to control the Birth Rate. At every frame where the value is set to 1 it will emitt 1 particle. If you set the value to 2 it will naturally then output 2 particles in quick succesion. (Se attachment below for example)

Another way to achieve the same thing is by leaving the Birth Rate at 1, setting Generate By to Frame and then setting Key Effect to Key. Now at every frame where you make a positional keyframe for the emitter it will emitt 1 particle.

As you may have gathered there is no bug in the emission, it's just random by default. Probably because that is what's needed most frequently and an optional input of "X particles every X frames" would just clutter things up for something that is resonably quick and easy to set up anyways, once you know how ;)

08-08-2003, 06:04 PM

08-09-2003, 05:01 AM
Wicked idea evenflcw, looks like that'll sort it out good 'n' propper. :D I completely forgot about using envelopes :P

Looks like someone else will be using that idea too ;)