Create your own game

Build Your First Browser Game with Three.js

Set up a Three.js scene, add a camera, lights and a player object, and write a render loop that turns it into a small playable 3D browser game.

By Pixelfork Team1 min read

Cover illustration: Exploring the Unity game engine, a beginner's guide, with a stone tower in a mountain valley

Three.js makes WebGL approachable. With a scene, a camera and a render loop, you can have a 3D game running in any modern browser in under a hundred lines.

The three essentials

Every Three.js app needs a scene, a camera and a renderer:

import * as THREE from "three";

const scene = new THREE.Scene();
const camera = new THREE.PerspectiveCamera(60, innerWidth / innerHeight, 0.1, 100);
camera.position.set(0, 4, 8);

const renderer = new THREE.WebGLRenderer({ antialias: true });
renderer.setSize(innerWidth, innerHeight);
document.body.appendChild(renderer.domElement);

Add light and a player

scene.add(new THREE.HemisphereLight(0xffffff, 0x333333, 2));

const player = new THREE.Mesh(
  new THREE.BoxGeometry(1, 1, 1),
  new THREE.MeshStandardMaterial({ color: 0xf26207 })
);
scene.add(player);

Input and the game loop

const keys = new Set();
addEventListener("keydown", (e) => keys.add(e.key));
addEventListener("keyup", (e) => keys.delete(e.key));

const clock = new THREE.Clock();
renderer.setAnimationLoop(() => {
  const dt = clock.getDelta();
  const speed = 5 * dt;
  if (keys.has("ArrowLeft")) player.position.x -= speed;
  if (keys.has("ArrowRight")) player.position.x += speed;
  renderer.render(scene, camera);
});

setAnimationLoop syncs with the display refresh rate, and clock.getDelta() keeps movement independent of frame rate.

Handle resizing

addEventListener("resize", () => {
  camera.aspect = innerWidth / innerHeight;
  camera.updateProjectionMatrix();
  renderer.setSize(innerWidth, innerHeight);
});

Next steps

  • Load real models with GLTFLoader.
  • Add collisions with a physics library such as Rapier.
  • Cap the renderer pixel ratio at 2 so it stays fast on high-DPI phones.

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