Particles properties over time

[V!nc3r]

Is it possible to set a startColor for particles ? I know there is color1, color2 & colorDead, but i want to avoid the "pop" when a particle is emit, and for that i want to set a full transparent color, which gradually switch to color1 & color2.

Also, it could be cool to tell a particle that its size change over time (become bigger or smaller), i don't know if this option exist.

[GameMonetize]

Hello!

The idea to apply your changes could be to provide your own updateFunction.

http://doc.babylonjs.com/tutorials/Particles#custom-functions

[chicagobob123]

Yes yes. On intialize you can create a time member and fill it and decide what to do over time. 

var timeInSec=var time = new Date().getTime()/1000; 

You can add that to each particle. 

p.timeInSec=var time = new Date().getTime()/1000;  on initialization. 

When you do the update you can decide what you want have happen. Maybe alter the scale over time? 

 

[V!nc3r]

Ok thanks. These are kind of things that scared graphist usually ahah

[Wingnut]

Hi guys.  Let's take a look at some custom particle functions.

http://www.babylonjs-playground.com/#WQBB3#4

Right after I create the PS particle system in line 49, I set the customUpdateFunc in line 50. 

After that, myupdateFunction is used for updating... instead of the default one. 

In myupdateFunction, I no longer use color1, color2, and colorDead, and instead just make the particles change to a different random color each update cycle (lines 36-38).  Notice in lines 28 and 29 that each particle has an age and lifeTime properties, by default.  A simple if (particle.age > ???) {...} could easily be used in your custom update func.

Let's look at a standard default update function... https://github.com/BabylonJS/Babylon.js/blob/master/src/Particles/babylon.particleSystem.js#L99 .  Notice that a value called _scaledUpdateSpeed is used heavily... and that might be a helper for you, too, @V!nc3r.

My demo goes a bit further, and also uses a customStartPosition function, too.  (lines 58-148).  This is how I accomplished 24 emitters.  Notice that the installation of the startPositionFunction is not done the same (no line 50 for startPositionFunction)... so you must name your "override" function... startPositionFunction.   But I could have also done ps.startPositionFunction = myStartPositionFunction... and that would have worked, too.

All in all, study this playground a bit, and in no time, you will be making custom/override functions for our standard and SPS particle systems... with good success.  Party(cle) on!

[aWeirdo]

Very interesting question,

What i personally did, was that i made the particalsystem a "child" of the emitter, the emitter is then stored in an array of emitters (containing all emitters & particalSystems of my scene)

var emitter = [];

//function that creates a new emitter & particle system.. i don't have long so, need to get to work, so i'll only post critical points.

emitter[id].particleSystem = new BABYLON.ParticleSystem("particles", 2000, scene);

I then added a specific "updateType"(custom) Id to the particle system depending on what it is and what i want to change over time.

emitter[id].updateType = 1;

in my case 1 is for adding a "tail" to a moving ball of fire.(reducing the size of each particle as it gets older)

I then go though each emitter in the renderLoop, check the updateType and for updateType === 1, i reduce the size of the particles as they grow older .

particles can be accessed from emitter[id].particleSystem.particles.

try to make a PG and play around with it, console.log to see what's what  have fun and good luck!

hopefully this added another idea of how to work with particles.