pixijs-ticker

name: pixijs-ticker description: "Use this skill when running per-frame logic or controlling the PixiJS v8 render loop. Covers Ticker.add/addOnce/remove, deltaTime vs deltaMS vs elapsedMS, UPDATE_PRIORITY ordering, maxFPS/minFPS capping, speed scaling, Ticker.shared vs new instances, per-object onRender hook, manual rendering. Triggers on: Ticker, UPDATE_PRIORITY, deltaTime, deltaMS, elapsedMS, onRender, app.ticker, maxFPS, minFPS, Ticker.shared." license: MIT

app.ticker runs registered callbacks every frame and drives app.render() at UPDATE_PRIORITY.LOW. Each callback receives the Ticker instance; read deltaTime as a frame-rate-independent multiplier (≈1.0 at 60fps) or deltaMS for real-time calculations.

Quick Start

app.ticker.add((ticker) => {
  sprite.rotation += 0.01 * ticker.deltaTime;
  sprite.x += (200 / 1000) * ticker.deltaMS;
});

app.ticker.add(
  (ticker) => {
    updatePhysics(ticker.deltaMS);
  },
  undefined,
  UPDATE_PRIORITY.HIGH,
);

app.ticker.maxFPS = 30;
app.ticker.speed = 0.5;

sprite.onRender = () => {
  sprite.scale.x = Math.sin(performance.now() / 500);
};

Related skills: pixijs-application (Application setup and sharedTicker option), pixijs-performance (frame rate optimization), pixijs-migration-v8 (v7 ticker signature changes).

Core Patterns

Time units

The Ticker exposes three timing values, each for different use cases:

import { Application } from "pixi.js";

const app = new Application();
await app.init({ width: 800, height: 600 });

app.ticker.add((ticker) => {
  // deltaTime: dimensionless scalar, ~1.0 at 60fps
  sprite.rotation += 0.1 * ticker.deltaTime;

  // deltaMS: real milliseconds (speed-scaled, capped)
  sprite.x += (200 / 1000) * ticker.deltaMS; // 200 pixels per second

  // elapsedMS: raw milliseconds (no scaling, no cap)
  console.log(`Raw frame time: ${ticker.elapsedMS}ms`);
});

Tension note: deltaTime is not milliseconds. It is deltaMS * Ticker.targetFPMS where targetFPMS is 0.06 (i.e. 1/16.67). At exactly 60fps, deltaTime is 1.0. At 30fps, deltaTime is 2.0. This catches people who treat it as a time value.

Priority ordering and context binding

import { Application, UPDATE_PRIORITY } from "pixi.js";

const app = new Application();
await app.init({ width: 800, height: 600 });

// INTERACTION (50) > HIGH (25) > NORMAL (0) > LOW (-25) > UTILITY (-50)
// app.render() is registered at LOW by the TickerPlugin

app.ticker.add(
  (ticker) => {
    // Physics runs before normal-priority callbacks
    updatePhysics(ticker.deltaMS);
  },
  undefined,
  UPDATE_PRIORITY.HIGH,
);

app.ticker.add((ticker) => {
  // Default priority (NORMAL = 0), runs after HIGH but before render
  updateAnimations(ticker.deltaTime);
});

// Pass `this` as the second argument to preserve context on class methods
class GameSystem {
  public speed = 5;
  public position = 0;

  public update(ticker: Ticker): void {
    this.position += this.speed * ticker.deltaTime;
  }
}

const system = new GameSystem();
app.ticker.add(system.update, system);
app.ticker.remove(system.update, system); // must match both fn and context

Frame rate capping

import { Ticker } from "pixi.js";

const ticker = new Ticker();

ticker.maxFPS = 30; // Cap at 30fps (skips frames to maintain interval)
ticker.minFPS = 10; // Cap deltaTime so it never exceeds 10fps worth

// If maxFPS < minFPS, minFPS is lowered to match
// If minFPS > maxFPS, maxFPS is raised to match

maxFPS skips update calls to enforce a ceiling. minFPS caps deltaTime/deltaMS so large frame drops don't produce enormous deltas (default minFPS is 10).

Per-object onRender hook

import { Sprite, Assets, Application } from "pixi.js";

const app = new Application();
await app.init({ width: 800, height: 600 });

const texture = await Assets.load("bunny.png");
const sprite = new Sprite(texture);
app.stage.addChild(sprite);

sprite.onRender = (renderer) => {
  sprite.rotation += 0.01;
};

onRender is called during scene graph traversal, before GPU rendering. It is an alternative to a global ticker callback when logic is tied to a specific display object.

Ticker.shared, Ticker.system, and new Ticker

import { Ticker, UPDATE_PRIORITY } from "pixi.js";

// Ticker.shared: singleton, autoStart=true, protected from destroy()
const shared = Ticker.shared;

// Ticker.system: separate instance used by engine background tasks,
// independent of the main scene ticker. It's a plain Ticker instance
// (autoStart=true, _protected=true) with no intrinsic priority; listeners
// are typically added at UTILITY priority by convention.
const system = Ticker.system;

// new Ticker(): custom instance, autoStart=false, you manage the lifecycle
const custom = new Ticker();
custom.autoStart = true; // start when first listener is added
custom.add((ticker) => {
  console.log(ticker.deltaMS);
});

// One-shot callback that auto-removes after firing
custom.addOnce(() => console.log("fires once"), null, UPDATE_PRIORITY.NORMAL);

// When done:
custom.stop();
custom.destroy();

Application creates its own Ticker by default. Set sharedTicker: true in app.init() to use Ticker.shared instead. Ticker.shared and Ticker.system are both _protected and will not actually be destroyed if you call destroy() on them. Read ticker.FPS for the measured frame rate and ticker.count for the current listener count.

App lifecycle and manual rendering

import { Application } from "pixi.js";

const app = new Application();
await app.init({ autoStart: false });

// Pause and resume the built-in render loop at any time.
app.start();
app.stop();

// Or drive the loop yourself (headless, visibility-gated, fixed timestep, etc.)
function animate() {
  app.ticker.update(); // fires registered callbacks
  app.render(); // renders the stage
  requestAnimationFrame(animate);
}
animate();

app.start() and app.stop() are added by the TickerPlugin and map to ticker.start() / ticker.stop(). Use autoStart: false plus your own frame driver when you need to pause on tab blur, run a fixed-timestep loop, or render offscreen.

Speed scaling

import { Application } from "pixi.js";

const app = new Application();
await app.init({ width: 800, height: 600 });

app.ticker.speed = 0.5; // Half speed (slow motion)
app.ticker.speed = 2.0; // Double speed

// speed affects deltaTime and deltaMS, but NOT elapsedMS

Common Mistakes

[CRITICAL] Ticker callback expects delta as first argument

Wrong:

app.ticker.add((dt) => {
  bunny.rotation += dt;
});

Correct:

app.ticker.add((ticker) => {
  bunny.rotation += ticker.deltaTime;
});

v8 passes the Ticker instance as the callback argument, not a delta number. The v7 pattern (dt) => ... compiles but dt is the entire Ticker object, so arithmetic on it produces NaN.

[HIGH] Using updateTransform for per-frame logic

Wrong:

class MySprite extends Sprite {
  updateTransform() {
    super.updateTransform();
    this.rotation += 0.01;
  }
}

Correct:

class MySprite extends Sprite {
  constructor() {
    super();
    this.onRender = this._onRender.bind(this);
  }
  private _onRender() {
    this.rotation += 0.01;
  }
}

updateTransform was removed in v8. Use the onRender callback for per-object per-frame logic.

[MEDIUM] Treating deltaTime as milliseconds

Wrong:

app.ticker.add((ticker) => {
  // Tries to move 100px/sec but deltaTime is ~1.0, not ~16.67
  sprite.x += (100 * ticker.deltaTime) / 1000;
});

Correct:

app.ticker.add((ticker) => {
  // Using deltaMS for time-based movement
  sprite.x += (100 / 1000) * ticker.deltaMS;
  // Or using deltaTime as a frame-rate multiplier
  sprite.x += 1.5 * ticker.deltaTime;
});

deltaTime is a dimensionless scalar (~1.0 at 60fps), not milliseconds. Use deltaMS for real time calculations. Use deltaTime as a simple multiplier when you want "per frame at 60fps" behavior.

API Reference

• Ticker
• TickerPlugin
• TickerPluginOptions