# GPUParticleSystem with CustomParticleEmitter and LifeTime

Hello world

I have two questions about GPUParticleSystem and CustomParticleEmitter.

1. I use these properties for GPUParticleSystem to control lifetime with a custom particle emitter.
``````let particletime = 0;

particletime = 0.25;
particletime = 0.1;
particletime = 0.07;
particletime = 0.04;
particletime = 0.03;
particletime = 0.02;
particletime = 0.013;
particletime = 0.009;

``````

Anyone got a better solution instead of this â€śhackâ€ť ?

1. Is plans to support a path of positions for custom particle emitter, or is this not possible ?
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Hello world to you! Letâ€™s see what I can do for you.

1. I use these properties for GPUParticleSystem to control lifetime with a custom particle emitter.

Iâ€™d like to understand more what your intention is? Looks like youâ€™re setting the size relative to the life time of the particle. Another solution is would be to just create an equation that converts the maxLifeTime to a particleTime . For example:

`let particletime = 1 / ps.maxLifeTime;`
This number gets smaller as maxLifeTimer goes up which is the relation you have in your example.

1. Is plans to support a path of positions for custom particle emitter, or is this not possible ?

Is the intention for the emitter to go along a certain path? This Iâ€™m sure can be done. Take a look at this demo. https://playground.babylonjs.com/#36UHXZ#34

Here is a another demo showing manipulations you can do particle systems and even animations you can add to the emitter (line 160-170) https://playground.babylonjs.com/#ZHL9ZF

OR do you want to make a path is the particles themselves? I know it is is possible to set the position of particles in solid particle system (SPS). https://playground.babylonjs.com/#GLZ1PX#8

Take a look at line 42 for instance:
` particle.position.y = particle.props.range * (1 + Math.cos(particle.props.angle))`

Let me know if you have questions to this.

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