Particles

Particle System

Creating and controlling particle effects in Phaser 4 -- ParticleEmitter creation and configuration, emitter ops (value formats), gravity wells, emission and death zones, flow vs burst modes, following game objects, and particle callbacks.

Key source paths: src/gameobjects/particles/ Related skills: ../sprites-and-images/SKILL.md, ../loading-assets/SKILL.md

Quick Start

// In a Scene's create() method:

// Basic continuous emitter (flow mode)
const emitter = this.add.particles(400, 300, 'flares', {
    frame: 'red',
    speed: 200,
    lifespan: 2000,
    scale: { start: 1, end: 0 },
    alpha: { start: 1, end: 0 },
    gravityY: 150
});

// One-shot burst (explode mode)
const burst = this.add.particles(400, 300, 'flares', {
    frame: 'blue',
    speed: { min: 100, max: 300 },
    lifespan: 1000,
    scale: { start: 0.5, end: 0 },
    emitting: false   // don't auto-start
});
burst.explode(20);    // emit 20 particles at once

Core Concepts

ParticleEmitter

ParticleEmitter extends GameObject and is added directly to the display list. It is both a game object (positionable, scalable, maskable) and the emitter itself. There is no separate manager -- this.add.particles() returns a ParticleEmitter instance.

Factory signature:

this.add.particles(x, y, texture, config);
// x, y: world position (both optional, default 0)
// texture: string key or Texture instance
// config: ParticleEmitterConfig object (optional, can call setConfig later)

Mixins: AlphaSingle, BlendMode, Depth, Lighting, Mask, RenderNodes, ScrollFactor, Texture, Transform, Visible. So you can call setPosition(), setScale(), setDepth(), setBlendMode(), setMask(), setScrollFactor(), etc.

Particle

A lightweight object owned by its emitter. Key properties: x, y, velocityX/Y, accelerationX/Y, scaleX/Y, alpha, angle, rotation, tint, life (total ms), lifeCurrent (remaining ms), lifeT (0-1 normalized), bounce, delayCurrent, holdCurrent. Particles are pooled internally -- you never create them manually.

EmitterOp Value Formats

Most config properties (speed, scale, alpha, angle, x, y, etc.) accept flexible value formats:

x: 400                                        // static value
x: [100, 200, 300, 400]                       // random pick from array
x: { min: 100, max: 700 }                     // random float in range
x: { min: 100, max: 700, int: true }          // random integer
x: { random: [100, 700] }                     // random integer shorthand
scale: { start: 0, end: 1 }                   // ease over lifetime (default linear)
scale: { start: 0, end: 1, ease: 'bounce.out' }  // custom ease
scale: { start: 4, end: 0.5, random: true }   // random start, ease to end
x: { values: [50, 500, 200, 800], interpolation: 'catmull' }  // interpolation
x: { steps: 32, start: 0, end: 576 }          // stepped sequential
x: { steps: 32, start: 0, end: 576, yoyo: true }  // stepped with yoyo
x: {                                           // custom callbacks
    onEmit: (particle, key, t, value) => value,
    onUpdate: (particle, key, t, value) => value
}
x: (particle, key, t, value) => value + 50    // emit-time callback shorthand

Emit-only (no onUpdate): angle, delay, hold, lifespan, quantity, speedX, speedY. Emit + Update (support start/end, onUpdate): accelerationX/Y, alpha, bounce, maxVelocityX/Y, moveToX/Y, rotate, scaleX/Y, tint, x, y.

Flow vs Explode (Burst)

Flow mode (frequency >= 0): emits quantity particles every frequency ms. Default is frequency: 0 (every frame) with emitting: true.

Explode mode (frequency = -1): emits a batch all at once, then stops.

emitter.flow(100, 5);           // 5 particles every 100ms
emitter.flow(100, 5, 50);       // auto-stop after 50 total
emitter.explode(30, 200, 400);  // burst 30 at position
emitter.explode(30);            // burst at emitter position

Common Patterns

Scale, Alpha, and Color Over Lifetime

// Scale and alpha with custom easing
this.add.particles(400, 300, 'spark', {
    lifespan: 2000,
    speed: 100,
    scale: { start: 1, end: 0, ease: 'power2' },
    alpha: { start: 1, end: 0, ease: 'cubic.in' }
});

Color Interpolation

The color property interpolates through an array of colors over particle lifetime (overrides tint):

this.add.particles(400, 300, 'spark', {
    lifespan: 2000, speed: 100, scale: { start: 0.5, end: 0 },
    color: [0xfacc22, 0xf89800, 0xf83600, 0x9f0404], colorEase: 'quad.out'
});

Tinting Particles

this.add.particles(400, 300, 'spark', { tint: 0xff0000 });                           // static
this.add.particles(400, 300, 'spark', { tint: { start: 0xffffff, end: 0xff0000 } }); // over lifetime

Gravity Wells

A GravityWell applies inverse-square gravitational force, pulling (or repelling with negative power) particles toward a point.

const emitter = this.add.particles(400, 300, 'spark', {
    speed: 100, lifespan: 4000, scale: { start: 0.4, end: 0 }, quantity: 2
});

const well = emitter.createGravityWell({
    x: 400, y: 300, power: 2, epsilon: 100, gravity: 50
});

// Update at runtime
well.x = 300;
well.power = -1;  // negative = repel

// Or create manually and add
const well2 = new Phaser.GameObjects.Particles.GravityWell(500, 200, 3, 100, 50);
emitter.addParticleProcessor(well2);
emitter.removeParticleProcessor(well2);

Emission Zones (Random)

A RandomZone spawns particles at random positions within a shape. The source must have a getRandomPoint(point) method -- all Phaser geometry classes (Circle, Ellipse, Rectangle, Triangle, Polygon, Line) support this, or provide a custom source:

// Using built-in geometry
this.add.particles(400, 300, 'spark', {
    speed: 50, lifespan: 2000,
    emitZone: { type: 'random', source: new Phaser.Geom.Circle(0, 0, 100) }
});

// Custom source object (any object with getRandomPoint)
emitter.addEmitZone({
    type: 'random',
    source: {
        getRandomPoint: (point) => {
            const a = Math.random() * Math.PI * 2;
            point.x = Math.cos(a) * 100;
            point.y = Math.sin(a) * 50;
            return point;
        }
    }
});

Emission Zones (Edge)

An EdgeZone places particles sequentially along shape edges. The source must have a getPoints(quantity, stepRate) method. Curves, Paths, and all geometry shapes support this:

this.add.particles(400, 300, 'spark', {
    lifespan: 1500, speed: 20,
    emitZone: {
        type: 'edge',
        source: new Phaser.Geom.Circle(0, 0, 150),
        quantity: 48,     // number of points on edge (use 0 with stepRate instead)
        yoyo: false,      // reverse direction at ends
        seamless: true    // remove duplicate endpoint
    }
});

// Or add post-creation with any source that has getPoints
emitter.addEmitZone({ type: 'edge', source: geom, quantity: 50, yoyo: false, seamless: true });

Multiple emission zones: Pass an array to emitZone or call addEmitZone() multiple times. Zones iterate in sequence. The total property controls how many particles emit before rotating to the next zone (-1 = never rotate).

this.add.particles(400, 300, 'spark', {
    emitZone: [
        { type: 'random', source: new Phaser.Geom.Circle(0, 0, 50) },
        { type: 'random', source: new Phaser.Geom.Circle(200, 0, 50) }
    ]
});

Death Zones

A DeathZone kills particles when they enter (or leave) a region. The source must have a contains(x, y) method.

// Kill particles entering a rectangle
this.add.particles(400, 100, 'spark', {
    speed: 200, lifespan: 5000, gravityY: 100,
    deathZone: { type: 'onEnter', source: new Phaser.Geom.Rectangle(300, 400, 200, 50) }
});

// Kill particles leaving a circle (confine to area)
this.add.particles(400, 300, 'spark', {