ParticleSystem2D

EffectsScripts: ParticleSystem2DComponentFeature: Particle System 2D (≈90 KB)

Optional feature

ParticleSystem2D is part of Particle System 2D. A build includes it only when a scene, prefab or script uses it — see Feature cropping.

From a script

import { ParticleSystem2DComponent } from "mmpx";

const particleSystem2D = this.entity.TryGetComponent(ParticleSystem2DComponent);

Full API: ParticleSystem2DComponent.

Fields

Field	Type	Default	Description
Duration duration	number (0.05 … ∞) (s)	5	Length of one cycle — emission curves and bursts run over it
Looping looping	boolean	true
Prewarm prewarm	boolean	false	Starts as if one full cycle had already run
Start Delay startDelay	MinMaxCurve (s)	0	Wait before emission starts (constant or random)
Start Lifetime startLifetime	MinMaxCurve (s)	2	How long each particle lives. Curves run over the system's cycle
Start Speed startSpeed	MinMaxCurve (px/s)	200	Initial speed along the shape's direction
Separate Size Axes startSizeSeparate	boolean	false
Start Size startSize	MinMaxCurve (px)	32	Width in pixels (the height follows the texture's aspect)
Start Size Y startSizeY	MinMaxCurve (px)	32
Start Rotation startRotation	MinMaxCurve (°)	0
Flip Rotation flipRotation	number (0 … 1)	0	Share of particles that rotate the other way
Start Color startColor	MinMaxGradient	16777215
Gravity Modifier gravityModifier	MinMaxCurve	0	× gravity (980 px/s² down). Curves run over each particle's life
Simulation Space simulationSpace	"local" | "world"	"local"	Local: particles move with the entity. World: they stay where they were emitted (trails)
Simulation Speed simulationSpeed	number (0 … ∞)	1
Use Unscaled Time useUnscaledTime	boolean	false	Ignore Game.time's time scale (still holds while the game is paused)
Play On Awake playOnAwake	boolean	true
Max Particles maxParticles	number (1 … 100000)	1000
Stop Action stopAction	"none" | "disable" | "destroy" | "callback"	"none"	When every particle is gone after a stop or the last cycle: deactivate or destroy the entity, or just send OnParticleSystemStopped (always sent)
Auto Random Seed autoRandomSeed	boolean	true	A new random sequence each play. Off: the same every time (randomSeed)
Random Seed randomSeed	number	0
Emission Enabled emissionEnabled	boolean	true
Shape Enabled shapeEnabled	boolean	true
Velocity Enabled velocityEnabled	boolean	false
Limit Velocity Enabled limitVelocityEnabled	boolean	false
Inherit Velocity Enabled inheritVelocityEnabled	boolean	false
Force Enabled forceEnabled	boolean	false
Color Over Lifetime Enabled colorOverLifetimeEnabled	boolean	false
Color By Speed Enabled colorBySpeedEnabled	boolean	false
Size Over Lifetime Enabled sizeOverLifetimeEnabled	boolean	false
Size By Speed Enabled sizeBySpeedEnabled	boolean	false
Rotation Over Lifetime Enabled rotationOverLifetimeEnabled	boolean	false
Rotation By Speed Enabled rotationBySpeedEnabled	boolean	false
Noise Enabled noiseEnabled	boolean	false
Collision Enabled collisionEnabled	boolean	false
Texture Sheet Enabled textureSheetEnabled	boolean	false
Trails Enabled trailsEnabled	boolean	false

Emission

Field	Type	Default	Description
Rate Over Time rateOverTime	MinMaxCurve (/s)	10	Particles per second. Curves run over the cycle
Rate Over Distance rateOverDistance	MinMaxCurve (/px)	0	Particles per pixel the entity moves — trails
Bursts bursts	json	[]	Extra particles at set times in the cycle

Shape

Field	Type	Default	Description
Shape shape	"cone" | "circle" | "edge" | "rectangle" | "point"	"cone"
Angle shapeAngle	number (0 … 90) (°)	25	Spread either side of up, widening across the base
Radius shapeRadius	number (0 … ∞) (px)	10
Radius Thickness radiusThickness	number (0 … 1)	1	0 emits from the edge only, 1 from the whole area
Arc shapeArc	number (0 … 360) (°)	360
Mode arcMode	"random" | "loop" | "pingPong" | "burstSpread"	"random"	Where along the arc / edge: random, sweeping round, back and forth, or each emission spread evenly
Spread arcSpread	number (0 … 1)	0	Only emit at multiples of this fraction (0 = anywhere)
Speed arcSpeed	number (/s)	1
Length shapeLength	number (0 … ∞) (px)	100
Shape Width shapeWidth	number (0 … ∞) (px)	100
Shape Height shapeHeight	number (0 … ∞) (px)	100
Emit From Edge emitFromEdge	boolean	false	Emit from the outline, outwards
Position shapePosition	[x, y]	[0,0]
Rotation shapeRotation	number (°)	0
Scale shapeScale	[x, y]	[1,1]
Align To Direction alignToDirection	boolean	false	Turn each particle to face its starting direction
Randomize Direction randomizeDirection	number (0 … 1)	0
Circularize Direction sphericalizeDirection	number (0 … 1)	0	Blend towards pointing out from the centre
Randomize Position randomizePosition	number (0 … ∞) (px)	0

Velocity over Lifetime

Field	Type	Default	Description
Velocity X velocityX	MinMaxCurve (px/s)	0
Velocity Y velocityY	MinMaxCurve (px/s)	0
Space velocitySpace	"local" | "world"	"local"
Orbital orbitalVelocity	MinMaxCurve (°/s)	0	Circling the emitter (plus Offset)
Offset orbitalOffset	[x, y]	[0,0]
Radial radialVelocity	MinMaxCurve (px/s)	0	Away from (negative: towards) the orbit centre
Speed Modifier speedModifier	MinMaxCurve	1

Limit Velocity over Lifetime

Field	Type	Default	Description
Speed speedLimit	MinMaxCurve (px/s)	100
Dampen dampen	number (0 … 1)	0.5	How quickly speed over the limit is removed
Drag drag	MinMaxCurve	0	Fraction of velocity lost per second
Multiply Drag By Size multiplyDragBySize	boolean	false
Multiply Drag By Velocity multiplyDragByVelocity	boolean	false

Inherit Velocity

Field	Type	Default	Description
Mode inheritVelocityMode	"initial" | "current"	"initial"	Initial: particles keep the entity's velocity at birth. Current: they follow its velocity every frame
Multiplier inheritVelocity	MinMaxCurve	0.5

Force over Lifetime

Field	Type	Default	Description
Force X forceX	MinMaxCurve (px/s²)	0
Force Y forceY	MinMaxCurve (px/s²)	0
Space forceSpace	"local" | "world"	"local"
Randomize forceRandomize	boolean	false	A random force between the two values every frame (two-value modes)

Color over Lifetime

Field	Type	Default	Description
Color colorOverLifetime	MinMaxGradient	see the Inspector

Color by Speed

Field	Type	Default	Description
Color colorBySpeed	MinMaxGradient	see the Inspector
Speed Range colorSpeedRange	[x, y]	[0,400]

Size over Lifetime

Field	Type	Default	Description
Separate Axes sizeSeparateAxes	boolean	false
Size sizeOverLifetime	MinMaxCurve	see the Inspector	× start size
Size Y sizeOverLifetimeY	MinMaxCurve	see the Inspector

Size by Speed

Field	Type	Default	Description
Size sizeBySpeed	MinMaxCurve	see the Inspector
Speed Range sizeSpeedRange	[x, y]	[0,400]

Rotation over Lifetime

Field	Type	Default	Description
Angular Velocity angularVelocity	MinMaxCurve (°/s)	45

Rotation by Speed

Field	Type	Default	Description
Angular Velocity rotationBySpeed	MinMaxCurve (°/s)	45
Speed Range rotationSpeedRange	[x, y]	[0,400]

Noise

Field	Type	Default	Description
Strength noiseStrength	MinMaxCurve (px/s)	60
Frequency noiseFrequency	number (0 … ∞)	0.01	Noise cells per pixel — lower is smoother
Scroll Speed noiseScrollSpeed	number	0	Moves the noise field over time
Octaves noiseOctaves	number (1 … 4)	1
Octave Multiplier noiseOctaveMultiplier	number (0 … 1)	0.5
Octave Scale noiseOctaveScale	number (1 … 4)	2
Position Amount noisePositionAmount	number	1
Rotation Amount noiseRotationAmount	number (°/s)	0
Size Amount noiseSizeAmount	number (0 … 1)	0

Collision

Field	Type	Default	Description
Plane collisionPlane	Entity	—	An entity whose position and up direction (+y) is a floor particles bounce off
Plane 2 collisionPlane2	Entity	—
Plane 3 collisionPlane3	Entity	—
Bounce bounce	number (0 … 2)	0.5
Dampen collisionDampen	number (0 … 1)	0	Speed lost on each hit
Lifetime Loss lifetimeLoss	number (0 … 1)	0	Share of its life a particle loses on each hit
Min Kill Speed minKillSpeed	number (0 … ∞) (px/s)	0	Particles slower than this after a hit die
Radius Scale radiusScale	number (0 … 1)	1	Collision radius as a share of half the size
Send Collision Events sendCollisionEvents	boolean	false	Emit a particles:collision event (and OnParticleCollision on scripts) per hit

Sub Emitter

Field	Type	Default	Description
Trigger subEmitterTrigger	"none" | "birth" | "death" | "collision"	"none"	Make this a sub-emitter of the nearest parent particle system: emit when its particles are born (trails), die or collide
Probability subEmitterProbability	number (0 … 1)	1
Inherit Color subEmitterInheritColor	boolean	false
Inherit Size subEmitterInheritSize	boolean	false
Inherit Rotation subEmitterInheritRotation	boolean	false

Texture Sheet Animation

Field	Type	Default	Description
Tiles X tilesX	number (1 … 64)	1
Tiles Y tilesY	number (1 … 64)	1
Animation sheetAnimation	"wholeSheet" | "singleRow"	"wholeSheet"
Row Mode sheetRowMode	"custom" | "random"	"custom"
Row sheetRow	number (0 … ∞)	0
Frame Over Time frameOverTime	MinMaxCurve	see the Inspector	0..1 across the frames, over each particle's life
Start Frame startFrame	MinMaxCurve	0	Frame offset (in frames)
Cycles sheetCycles	number (0.01 … ∞)	1	Times the animation runs over a life

Trails

Field	Type	Default	Description
Mode trailMode	"particles" | "ribbon"	"particles"	Particles: each particle leaves its own trail. Ribbon: one strip joins the particles from youngest to oldest
Ratio trailRatio	number (0 … 1)	1	Share of particles that get a trail
Lifetime trailLifetime	MinMaxCurve	0.4	How long a trail point lasts, as a share of its particle's life
Min Vertex Distance minVertexDistance	number (0.5 … ∞) (px)	6	A new trail point once the particle has moved this far — smaller is smoother
Ribbon Count ribbonCount	number (1 … 16)	1	Particles are shared out between this many ribbons
Width over Trail trailWidth	MinMaxCurve	see the Inspector	From the head (0) to the tail (1). × the particle's size, or px with Size Affects Width off
Size Affects Width sizeAffectsWidth	boolean	true
Inherit Particle Color inheritParticleColor	boolean	true
Color over Lifetime trailColorOverLifetime	MinMaxGradient	16777215	Over the particle's life
Color over Trail trailColorOverTrail	MinMaxGradient	see the Inspector	From the head (0) to the tail (1)
Texture trailAssetId	texture asset	—	Stretched along the trail, its height across it (empty: solid). Drawn under the particles

Renderer

Field	Type	Default	Description
Texture assetId	texture asset	—	Every particle's image (empty: a white square). Texture sheet tiles split it; a spritesheet frame works too
Blend Mode blendMode	"normal" | "add" | "multiply" | "screen"	"normal"	Add brightens where particles overlap — fire, sparks, magic
Render Mode renderMode	"billboard" | "stretched"	"billboard"	Stretched: each particle is drawn along its velocity
Length Scale lengthScale	number (0 … ∞)	2
Speed Scale speedScale	number (0 … ∞)	0	Extra length per px/s of speed
Sort Mode sortMode	"youngestInFront" | "oldestInFront"	"youngestInFront"
Flip X flipX	number (0 … 1)	0
Flip Y flipY	number (0 … 1)	0
Material material	material asset	—	A sprite-domain material drawn over all the particles at once