# Increasing the speed of particle emitter after scene restarts

**URL:** <https://phaser.discourse.group/t/increasing-the-speed-of-particle-emitter-after-scene-restarts/14843>\
**Category:** Phaser 3\
**Created:** [October 15, 2024, 1:48pm UTC](https://phaser.discourse.group/t/increasing-the-speed-of-particle-emitter-after-scene-restarts/14843 "2024-10-15T13:48:39Z")\
**Posts on this page:** 7\
**Page:** 1

<div class="post-metadata">

**Author:** ![Crusler](https://avatars.discourse-cdn.com/v4/letter/c/e99b99/32.png) [@Crusler](https://phaser.discourse.group/u/Crusler)\
**Post date:** [October 15, 2024, 1:48pm UTC](https://phaser.discourse.group/t/increasing-the-speed-of-particle-emitter-after-scene-restarts/14843/1 "2024-10-15T13:48:39Z")

</div>

Hi, evetyone !  
Get the problem with scene.restart();  
In the scene “create” function i make a particle emitter with fixed frequency. WIth each scene.restart this frequency doubles. Particlel emitter destroys at scene “shutdown” event.  
Speed of patricles is normal when i destroy and then recreate the emitter, buy after shutdown it doubles.

Here is the code:

```javascript
this.shape1 = new Phaser.Geom.Ellipse(0, 0, 400, 200);
this.emitter1 = this.add.particles(275, 160, 'leafgreen', {           
            blendMode: 'ADD',
            lifespan: {onEmit: function(particle, key, t, value) {return Phaser.Math.Between(5000, 10000)}},
            quantity: 1,
  	    speedX: {onEmit: function(particle, key, t, value) {return (-1)*Phaser.Math.Between(10, 40)}},
            speedY: {onEmit: function(particle, key, t, value) {return Phaser.Math.Between(10, 40)}},
			rotate: {start: Phaser.Math.Between(0, 300), end: 359},
            frequency: 150,			
	    alpha: { values: [0, 0.8, 0.01], interpolation: 'catmull', ease: Phaser.Math.Easing.Sine.Out },
            scale: { start: 0.1, end: 0.05 },
	    advance: 5000
        }).setDepth(2);
        this.emitter1.addEmitZone({ type: 'random', source: this.shape1, quantity: 64 });

```

At shutdown event:

```javascript
this.emitter1.stop(true);
this.emitter1.destroy(true);

```

Same code in Phaser sandbox cause no trouble even without destroing emitter.  
What could be the problem?

I’m using Phaser 3.8 and Phaser Editor 2.1.18

Thanx!

---

<div class="post-metadata">

**Author:** ![samme](https://yyz2.discourse-cdn.com/free1/user_avatar/phaser.discourse.group/samme/32/5275_2.png) [@samme](https://phaser.discourse.group/u/samme)\
**Post date:** [October 15, 2024, 1:56pm UTC](https://phaser.discourse.group/t/increasing-the-speed-of-particle-emitter-after-scene-restarts/14843/2 "2024-10-15T13:56:56Z")

</div>

👋

> [@Crusler](#):
>
> ```javascript
> this.emitter1.stop(true);
> this.emitter1.destroy(true);
> 
> ```

Try removing these.

---

<div class="post-metadata">

**Author:** ![Crusler](https://avatars.discourse-cdn.com/v4/letter/c/e99b99/32.png) [@Crusler](https://phaser.discourse.group/u/Crusler)\
**Post date:** [October 16, 2024, 9:35am UTC](https://phaser.discourse.group/t/increasing-the-speed-of-particle-emitter-after-scene-restarts/14843/3 "2024-10-16T09:35:11Z")

</div>

Not worked. But i noticed that sprite animations doubles too. Found on forum this:

```javascript
this.events.off('update');

```

and put it in shutdown event and it works, but i don’t understand why. any ideas?

---

<div class="post-metadata">

**Author:** ![samme](https://yyz2.discourse-cdn.com/free1/user_avatar/phaser.discourse.group/samme/32/5275_2.png) [@samme](https://phaser.discourse.group/u/samme)\
**Post date:** [October 16, 2024, 12:52pm UTC](https://phaser.discourse.group/t/increasing-the-speed-of-particle-emitter-after-scene-restarts/14843/4 "2024-10-16T12:52:01Z")

</div>

Which exact Phaser version is in the console, and can you show the whole scene code?

---

<div class="post-metadata">

**Author:** ![Crusler](https://avatars.discourse-cdn.com/v4/letter/c/e99b99/32.png) [@Crusler](https://phaser.discourse.group/u/Crusler)\
**Post date:** [October 17, 2024, 3:24am UTC](https://phaser.discourse.group/t/increasing-the-speed-of-particle-emitter-after-scene-restarts/14843/5 "2024-10-17T03:24:52Z")

</div>

I tried version 3.85 and latest 3.86. At this moment i’m using version 3.86  
Also in first boot scene in create function i launch UI scene witch shows user data, buttons, etc

```javascript
this.scene.launch('uiscene').bringToTop('uiscene');

```

This scene is third and here is the code

```javascript
class gamescene extends Phaser.Scene {
	
	constructor() {
	
		super("gamescene");
		
	}

//= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
	init() {
		// this is just for some usefull funcs, no event handlers or something here
		this.mlh = new MyLoaderHelper(this);

// does sprite objects destroys after scene restart or i should destroy them manualy ?
                this.objectsToDestroy = []; // array of sprite objects to destroy at shutdown event
		this.game.globals.currentScene = this; // this for "user interface" purpose
	}

// = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =

	create() {
		
		this.mlh.myConsoleDebug('create');				

		this.createEvents();
		this.createScene();

		this.generateLeafs();
		
		this.debugCamera();		

	}		

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
	update (time, delta) {
		if (this.controls != undefined) this.controls.update(delta); // cam controls
	}		
	
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
	createEvents() {
		this.mlh.myConsoleDebug('create events');
		
		this.input.off(Phaser.Input.Events.POINTER_UP).on(Phaser.Input.Events.POINTER_UP, (p) => {			
			this.scene.restart();
			//this.scene.start('gamescene'); // gamescene = this scene // do the same effect as this.scene.restart(); //imho
		});						
		this.events.off(Phaser.Scenes.Events.SHUTDOWN).once(Phaser.Scenes.Events.SHUTDOWN, () => {
			this.mlh.myConsoleDebug('shutdown event');
			this.destroyObjects();
			this.registry.destroy(); // i found it at this forum somewhere				
			this.events.off('update'); // this helps to fix the speed increasing
		});				
		this.events.off(Phaser.Scenes.Events.DESTROY).once(Phaser.Scenes.Events.DESTROY, () => {
			this.mlh.myConsoleDebug('destroy event');
			this.destroyObjects();
			this.registry.destroy();
			this.events.off('update');
		});
	}
		
	// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
	createScene(){
		let padd = 80; // road padding
		this.bg1 = this.add.sprite(0, 0, 's1bg1').setOrigin(0,0).setDepth(opt.DEPTH_BACKGROUND+2);
		let k = this.game.config.height/(this.bg1.height - padd);			
		this.bg1.setScale(k);		
		
		this.bg2 = this.add.sprite(0, 0, 's1bg2').setOrigin(0,0).setDepth(opt.DEPTH_BACKGROUND);
		this.bg2.setScale(k);		
		
		let ray = this.add.sprite(665, 120, 'ray').setOrigin(0.5,0.05).setDepth(opt.DEPTH_BACKGROUND+3).setBlendMode(Phaser.BlendModes.ADD).setAlpha(0.2).setScale(1.2);

		this.mlh.tweenAlpha(ray, 0.2, 0.8, 5000, Phaser.Math.Easing.Sine.Out, -1, true);
		this.mlh.tweenAngle(ray, 7, -7, 12000, Phaser.Math.Easing.Sine.InOut, -1, true)
		
		let ray2 = this.add.sprite(1200, 125, 'ray2').setOrigin(0,0).setDepth(opt.DEPTH_BACKGROUND+3).setBlendMode(Phaser.BlendModes.ADD).setAlpha(0.5).setScale(1);

		this.mlh.tweenAlpha(ray2, 0.1, 0.6, 7000, Phaser.Math.Easing.Sine.Out, -1, true);
		this.mlh.tweenAngle(ray2, ray2.angle, 10, 12000, Phaser.Math.Easing.Sine.InOut, -1, true);				
		
		this.tweens.add({
		    targets: lamp2, // this is ARRAY		    
		    alpha: { from: 0.1, to: 0.7 },
			ease: Phaser.Math.Easing.Bounce.Out,		    
		    duration: 500,
		    repeat: -1,
			yoyo: true,
			repeatDelay: 3000		    		
		});
			
				
		Phaser.Utils.Array.Add(this.objectsToDestroy, [this.bg1, this.bg2, ray, ray2]);
		
		this.sceneWidth = this.bg1.width*k;
		this.sceneHeight = this.bg1.height*k;
		
		this.cameras.main.setBounds(0, 0, this.sceneWidth, this.sceneHeight);
		this.physics.world.setBounds(0, 0, this.sceneWidth, this.sceneHeight);
	}

	// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
	generateLeafs(){
		
		this.mlh.myConsoleDebug('generateLeafs');				
		
		// left green tree
		this.shape1 = new Phaser.Geom.Ellipse(0, 0, 400, 200);

//##### this emitters 1,2,3,... has the double speed effect

        this.emitter1 = this.add.particles(275, 160, 'leafgreen', {           
            blendMode: 'ADD',
            lifespan: {onEmit: function(particle, key, t, value) {return Phaser.Math.Between(7000, 10000)}},
            quantity: 1,
			speedX: {onEmit: function(particle, key, t, value) {return (-1)*Phaser.Math.Between(10, 30)}},
            speedY: {onEmit: function(particle, key, t, value) {return Phaser.Math.Between(10, 40)}},
			rotate: {start: Phaser.Math.Between(0, 300), end: 359},
            frequency: 150,
			//alpha: {start: 0.8, end: 0.01},
			alpha: { values: [0, 0.8, 0.01], interpolation: 'catmull', ease: Phaser.Math.Easing.Sine.Out },
            scale: { start: 0.1, end: 0.05 },
			advance: 5000
        }).setDepth(opt.DEPTH_BACKGROUND+2);
        this.emitter1.addEmitZone({ type: 'random', source: this.shape1, quantity: 64 });

		// center green tree
		this.shape2 = new Phaser.Geom.Ellipse(0, 0, 300, 180);
        this.emitter2 = this.add.particles(800, 170, 'leafgreen', {           
            blendMode: 'ADD',
            lifespan: {onEmit: function(particle, key, t, value) {return Phaser.Math.Between(5000, 10000)}},
            quantity: 1,
			speedX: {onEmit: function(particle, key, t, value) {return (-1)*Phaser.Math.Between(10, 40)}},
            speedY: {onEmit: function(particle, key, t, value) {return Phaser.Math.Between(10, 40)}},
			rotate: {start: Phaser.Math.Between(0, 300), end: 359},
            frequency: 150,
			//alpha: {start: 0.8, end: 0.01},
			alpha: { values: [0, 0.8, 0.01], interpolation: 'catmull', ease: Phaser.Math.Easing.Sine.Out },
            scale: { start: 0.1, end: 0.05 },
			advance: 5000
        }).setDepth(opt.DEPTH_BACKGROUND+2);
        this.emitter2.addEmitZone({ type: 'random', source: this.shape2, quantity: 64 });

		// right green tree
		this.shape3 = new Phaser.Geom.Ellipse(0, 0, 260, 120);
        this.emitter3 = this.add.particles(1550, 160, 'leafgreen', {           
            blendMode: 'ADD',
            lifespan: {onEmit: function(particle, key, t, value) {return Phaser.Math.Between(5000, 10000)}},
            quantity: 1,
			speedX: {onEmit: function(particle, key, t, value) {return (-1)*Phaser.Math.Between(10, 40)}},
            speedY: {onEmit: function(particle, key, t, value) {return Phaser.Math.Between(10, 40)}},
			rotate: {start: Phaser.Math.Between(0, 300), end: 359},
            frequency: 150,
			//alpha: {start: 0.8, end: 0.01},
			alpha: { values: [0, 0.8, 0.01], interpolation: 'catmull', ease: Phaser.Math.Easing.Sine.Out },
            scale: { start: 0.1, end: 0.05 },
			advance: 5000
        }).setDepth(opt.DEPTH_BACKGROUND+2);
        this.emitter3.addEmitZone({ type: 'random', source: this.shape3, quantity: 50 });

		// right green tree
		this.shape4 = new Phaser.Geom.Ellipse(0, 0, 100, 70);
        this.emitter4 = this.add.particles(560, 270, 'leaforange', {           
            //blendMode: 'ADD',
            lifespan: {onEmit: function(particle, key, t, value) {return Phaser.Math.Between(5000, 10000)}},
            quantity: 1,
			speedX: {onEmit: function(particle, key, t, value) {return (-1)*Phaser.Math.Between(10, 40)}},
            speedY: {onEmit: function(particle, key, t, value) {return Phaser.Math.Between(10, 40)}},
			rotate: {start: Phaser.Math.Between(0, 300), end: 359},
            frequency: 200,
			//alpha: {start: 0.8, end: 0.01},
			alpha: { values: [0, 0.8, 0.01], interpolation: 'catmull', ease: Phaser.Math.Easing.Sine.Out },
            scale: { start: 0.08, end: 0.01 },
			advance: 2000
        }).setDepth(opt.DEPTH_BACKGROUND+2);
        this.emitter4.addEmitZone({ type: 'random', source: this.shape4, quantity: 35 });

		// red tree
		this.shape5 = new Phaser.Geom.Ellipse(0, 0, 100, 70);
        this.emitter5 = this.add.particles(800, 310, 'leaforangedark', {           
            //blendMode: 'ADD',
            lifespan: {onEmit: function(particle, key, t, value) {return Phaser.Math.Between(3000, 5000)}},
            quantity: 1,
			speedX: {onEmit: function(particle, key, t, value) {return (-1)*Phaser.Math.Between(10, 40)}},
            speedY: {onEmit: function(particle, key, t, value) {return Phaser.Math.Between(10, 40)}},
			rotate: {start: Phaser.Math.Between(0, 300), end: 359},
            frequency: 250,
			//alpha: {start: 0.8, end: 0.01},
			alpha: { values: [0, 0.8, 0.01], interpolation: 'catmull', ease: Phaser.Math.Easing.Sine.Out },
            scale: { start: 0.1, end: 0.02 },
			advance: 1500
        }).setDepth(opt.DEPTH_BACKGROUND+2);
        this.emitter5.addEmitZone({ type: 'random', source: this.shape5, quantity: 30 });

		Phaser.Utils.Array.Add(this.objectsToDestroy, [this.emitter1, this.emitter2, this.emitter3, this.emitter4, this.emitter5]);
	}
	

	
	// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
	destroyObjects(){				
		
// removing this.emitter1.stop(true) has no effect as i wrote earlier
		if (this.emitter1 != undefined) this.emitter1.stop(true);
		if (this.emitter2 != undefined) this.emitter2.stop(true);
		if (this.emitter3 != undefined)	this.emitter3.stop(true);
		if (this.emitter4 != undefined) this.emitter4.stop(true);
		if (this.emitter5 != undefined) this.emitter5.stop(true);
		if (this.smoke != undefined) this.smoke.stop(true);
		
                // is this correct way to destroy shape? do i need to destroy it?
		this.shape1.setEmpty(); this.shape1 = undefined;		
		this.shape2.setEmpty(); this.shape2 = undefined;
		this.shape3.setEmpty(); this.shape3 = undefined;
		this.shape4.setEmpty(); this.shape4 = undefined;
		this.shape5.setEmpty(); this.shape5 = undefined;
				
		if (this.objectsToDestroy != undefined && this.objectsToDestroy.length > 0) {
			
			this.mlh.myConsoleDebug('objectsToDestroy length: ' + this.objectsToDestroy.length);			
			Phaser.Utils.Array.RemoveBetween(this.objectsToDestroy, 0, this.objectsToDestroy.length, (item) => {
				if (item != undefined) {					
					this.tweens.killTweensOf(item);
					item.destroy(true);
					item = undefined;
				}
			}, this);
						
			this.objectsToDestroy = undefined;
			this.sceneInitialized = false;
			
		} else this.mlh.myConsoleDebug('#destroyObjects: no objects to destroy');
		
		this.mlh = null; // how to destroy class instance correctly?
		this.cursors = null;		
	}
		
		
	// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 
	debugCamera() {
				
		if (this.game.globals.isDebug) {
			this.mlh.myConsoleDebug('debugCamera');
			this.cursors = this.input.keyboard.createCursorKeys();
			const controlConfig = {
	            camera: this.cameras.main,
	            left: this.cursors.left,
	            right: this.cursors.right,
	            up: this.cursors.up,
	            down: this.cursors.down,
	            zoomIn: this.input.keyboard.addKey(Phaser.Input.Keyboard.KeyCodes.Q),
	            zoomOut: this.input.keyboard.addKey(Phaser.Input.Keyboard.KeyCodes.E),
	            acceleration: 0.03,
	            drag: 0.001,
	            maxSpeed: 1.0
	        };
	
	        this.controls = new Phaser.Cameras.Controls.SmoothedKeyControl(controlConfig);
		}
	}	
		
}

```

---

<div class="post-metadata">

**Author:** ![samme](https://yyz2.discourse-cdn.com/free1/user_avatar/phaser.discourse.group/samme/32/5275_2.png) [@samme](https://phaser.discourse.group/u/samme)\
**Post date:** [October 17, 2024, 4:26am UTC](https://phaser.discourse.group/t/increasing-the-speed-of-particle-emitter-after-scene-restarts/14843/6 "2024-10-17T04:26:01Z")

</div>

Remove these:

> [@Crusler](#):
>
> `this.events.off(Phaser.Scenes.Events.SHUTDOWN)`

> [@Crusler](#):
>
> `this.events.off(Phaser.Scenes.Events.DESTROY)`

The first one is causing the double-update problem because it doesn’t let the scene shut down.

Then remove these:

> [@Crusler](#):
>
> `this.events.off('update');`

Because the scene still needs to update after restarting.

> [@Crusler](#):
>
> ```javascript
> // does sprite objects destroys after scene restart or i should destroy them manualy ?
> this.objectsToDestroy = []; // array of sprite objects to destroy at shutdown event
> 
> ```

Game objects on the scene update list or display list are destroyed automatically when the scene stops or restarts. You don’t have to do anything with those.

> [@Crusler](#):
>
> `this.registry.destroy();`

You probably don’t want to destroy the game registry because it’s unusable after that. But also, if you’ve never put data in there then there’s nothing to remove, so just ignore it.

---

<div class="post-metadata">

**Author:** ![Crusler](https://avatars.discourse-cdn.com/v4/letter/c/e99b99/32.png) [@Crusler](https://phaser.discourse.group/u/Crusler)\
**Post date:** [October 17, 2024, 9:49am UTC](https://phaser.discourse.group/t/increasing-the-speed-of-particle-emitter-after-scene-restarts/14843/7 "2024-10-17T09:49:25Z")

</div>

God damn, brilliantly. It works! Greatly thanx!  
My bad! I thought that the code

```javascript
this.events.off(Phaser.Scenes.Events.SHUTDOWN).once(Phaser.Scenes.Events.SHUTDOWN, () => { ... });

```

turn off and then turn on (for 1 fire) event handler.