threejs-interaction

Three.js Interaction

Targets three.js r186. Examples use WebGLRenderer; the WebGPU and TSL section uses WebGPURenderer.

Quick Start

import * as THREE from "three";
import { OrbitControls } from "three/addons/controls/OrbitControls.js";

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

const scene = new THREE.Scene();
scene.background = new THREE.Color(0x111318);

const camera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, 0.1, 100);
camera.position.set(0, 1.5, 5);

const mesh = new THREE.Mesh(
  new THREE.BoxGeometry(1, 1, 1),
  new THREE.MeshStandardMaterial({ color: 0x3a86ff }),
);
scene.add(mesh);
const light = new THREE.DirectionalLight(0xffffff, 2);
light.position.set(3, 5, 4);
scene.add(light, new THREE.AmbientLight(0xffffff, 0.4));

const controls = new OrbitControls(camera, renderer.domElement); // connects itself
controls.enableDamping = true; // requires controls.update() every frame

const timer = new THREE.Timer();
timer.connect(document); // freezes the delta while the tab is hidden

const raycaster = new THREE.Raycaster();
const pointer = new THREE.Vector2();

function setPointer(event) {
  // NDC coordinates relative to the canvas, so the page can scroll or embed it
  const rect = renderer.domElement.getBoundingClientRect();
  pointer.set(
    ((event.clientX - rect.left) / rect.width) * 2 - 1,
    -((event.clientY - rect.top) / rect.height) * 2 + 1,
  );
}

renderer.domElement.addEventListener("pointerdown", (event) => {
  setPointer(event);
  raycaster.setFromCamera(pointer, camera);
  const hits = raycaster.intersectObject(mesh); // also tests children (recursive by default), as a loaded model needs
  if (hits.length > 0) console.log("clicked", hits[0].object);
});

function animate() {
  timer.update();
  controls.update(timer.getDelta());
  renderer.render(scene, camera);
}
renderer.setAnimationLoop(animate);