PixiJS Particle System

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AlphaBehavior<DataType, ParticleType> ​

Behavior used to control the transparency of particles over their lifetime.

Behavior supports three modes, a static mode where a single value is applied to all particles, a list mode where values are interpolated over the particle's lifetime based on a provided list, and a random mode where a random value from the list is applied to the particle upon initialization.

See ​

Example ​

ts
// Apply a static alpha value of 0.5 to all particles.
alphaBehavior.applyConfig({
    value: 0.5,
});

// Interpolate particle alpha from 0.0 to 1.0 over lifetime.
alphaBehavior.applyConfig({
    listData: [
        { time: 0.0, value: 0.0 },
        { time: 1.0, value: 1.0 },
    ],
    mode: "list",
});

// Assign a random alpha value between 0.2 and 0.8.
alphaBehavior.applyConfig({
    listData: [
        { time: 0.0, value: 0.2 },
        { time: 1.0, value: 0.8 },
    ],
    mode: "random",
});

Extends ​

Type Parameters ​

DataType ​

DataType extends BaseParticleData = BaseParticleData

Type describing the data object stored on particles.

ParticleType ​

ParticleType extends IEmitterParticle<DataType> = IEmitterParticle<DataType>

Type describing the particle used within the emitter.

Implements ​

Constructors ​

Constructor ​

ts
new AlphaBehavior<DataType, ParticleType>(emitter): AlphaBehavior<DataType, ParticleType>;

Creates new instance of AlphaBehavior.

Parameters ​

emitter ​

Emitter<DataType, ParticleType>

Emitter instance this behavior belongs to.

Returns ​

AlphaBehavior<DataType, ParticleType>

Overrides ​

EmitterBehavior.constructor

Accessors ​

list ​

Get Signature ​

ts
get list(): NumberList;

Number list used to interpolate alpha values over particle lifetime.

A behavior will always have a list, even when not using list-based configuration, but the list might not be initialized and will be empty in that case.

Returns ​

NumberList

mode ​

Get Signature ​

ts
get mode(): "static" | "list" | "random";

Mode currently used by the behavior.

Returns ​

"static" | "list" | "random"

Set Signature ​

ts
set mode(value): void;
Parameters ​
value ​

"static" | "list" | "random"

Returns ​

void

staticValue ​

Get Signature ​

ts
get staticValue(): number;

Alpha value applied to all particles in static mode.

Returns ​

number

Set Signature ​

ts
set staticValue(value): void;
Parameters ​
value ​

number

Returns ​

void

updateOrder ​

Get Signature ​

ts
get updateOrder(): BehaviorOrder;

Defines at which step of the update cycle the behavior is applied.

  • initial: Earliest step, useful when other behaviors depend on this behavior.
  • normal: Default step for most behaviors.
  • late: Latest step, useful for behaviors that should override others or depend on their properties.
Returns ​

BehaviorOrder

Implementation of ​

UpdateBehavior.updateOrder

Overrides ​

EmitterBehavior.updateOrder

Methods ​

applyConfig() ​

ts
applyConfig(config): void;

Reset the behavior and apply the provided configuration.

Parameters ​

config ​

AlphaBehaviorConfig

Behavior configuration.

Returns ​

void

Implementation of ​

UpdateBehavior.applyConfig

Overrides ​

EmitterBehavior.applyConfig

getConfig() ​

ts
getConfig():
  | AlphaBehaviorConfig
  | undefined;

Retrieve the current behavior properties as a configuration object. If the behavior is inactive, undefined is returned.

Returns ​

| AlphaBehaviorConfig | undefined

Behavior configuration object or undefined if inactive.

Implementation of ​

UpdateBehavior.getConfig

Overrides ​

EmitterBehavior.getConfig

init() ​

ts
init(particle): void;

Initialize the particle.

Parameters ​

particle ​

ParticleType

Particle to initialize.

Returns ​

void

Implementation of ​

InitBehavior.init

reset() ​

ts
protected reset(): void;

Reset the behavior to its default state.

Returns ​

void

Implementation of ​

UpdateBehavior.reset

Overrides ​

EmitterBehavior.reset

update() ​

ts
update(particle): void;

Updates the particle.

Parameters ​

particle ​

ParticleType

Particle to update.

Returns ​

void

Implementation of ​

UpdateBehavior.update