How do you change a particle systems emission Rate over Time in script?

Unity Engine
1

I’ve looked up forums and checked the scripting API but I just can’t figure out how to actually change a particle systems emission rate over time. All I want to do is get the referenced ParticleSystem’s emission module and change the Rate over Time. Why is this so hard to do?

2

Does it not work if you use this? Unity - Scripting API: ParticleSystem.EmissionModule.rateOverTime

3

A lot of particle control in google searches is deprecated - I think some Unity docs maybe are as well, but they may be updated now … ?

You access through rateOverTime

ParticleSystem yourParticle;
yourParticle.enableEmission = false;   /// directly turns off emission in the particle editor
...
var yourParticleEmission = yourParticle.emission;
...
yourParticleEmission.enabled = true;
...

yourParticleEmission.rateOverTime = yourEmissionRate;

// or for a funky light heavy effect:

yourParticleEmission.rateOverTime = Mathf.Lerp(particleEmissionMin, particleEmissionMax, startOfEmission/ emissionLength);
3 Likes
4

Hi! first of all, thank you for this but I was wondering whats the variable type of this is?

var yourParticleEmission = yourParticle.emission;

It says it is an EmissionModule type but I can’t find anything related to that…

5

It’s a ParticleSystem variable. :wink:

6

I wonder if this is expensive?

for(int i = 0; i < myParticleSystems.Length; i++) {
      var emission = myParticleSystems[i].emission;
      emission.rateOverTime = myEmissionRate;
}

or should I store the emission modules in an array on initialization and then iterate through them instead?

1 Like
7

using static UnityEngine.ParticleSystem;

8

LOL for some reason this works no problem:

var emission = myParticleSystem.emission;
emission.rateOverTime = myEmissionRate;

But this doesn’t even compile:

myParticleSystem.emission.rateOverTime = myEmissionRate;

4 Likes
9

If you would like the gory details of why, google up “c# properties returning structs”

Otherwise, when in doubt see the documentation, which shows you exactly the correct way. :slight_smile:

10

when you don’t know the type of a variable you can just “print(Things.GetType())”