Particles fading out

[personalnadir]

I'm trying to use the Emitter class to create a particle system where the particles slowly fade out as they age.

 

Initially I tried the following in the update loop

emitter.forEachAlive(function(p){  p.alpha-=alphaStep;}); 

However when I ran that, all the particles behaved as if they shared a common alpha value. I'm using the following initialisation line:

emitter = game.add.emitter(game.world.centerX, game.world.centerY, 250);emitter.makeParticles('sparks', ["spark1.png"], 200, false, false);

Where 'sparks' is a texture atlas. Any clues on where to look or what to approach to ensure that I can fade out particles individually? 

 

I'd also love to be able to render the particles using additive blending is that supported?

 

Thanks,

[Aizat]

If you are using lifespan

emitter.start(false, 1500, 20);function update() {	emitter.forEachAlive(function(p){		p.alpha= p.lifespan / emitter.lifespan;	});}

[personalnadir]

Thanks for that - that works wonderfully. But out of interest, why was my approach not working? I can see that in your you're setting the alpha to the ratio of the particles life, which is the nicer approach, but I would have thought that mine would just reduce the alpha evenly on each particle individually while actually it work of behaved as if it were globally. Are particles pooled?

[Aizat]

maybe

A new particle == old killed particle.

and alpha remains the same