Three.js is a powerful JavaScript library for creating 3D graphics on the web, but it doesn’t include built-in physics or complex interaction capabilities. To fill this gap, several frameworks and libraries integrate seamlessly with Three.js, providing robust physics engines and advanced interaction features. This article explores some of the best options available, helping you choose the right tools to enhance your Three.js projects.
Ammo.js
**Overview**:
Ammo.js is a direct port of the Bullet physics engine, a popular and powerful physics engine used in many games and simulations. It provides rigid body dynamics, soft body dynamics, and collision detection.
**Features**:
– **Rigid Body Dynamics**: Simulate realistic object movements and collisions.
– **Soft Body Dynamics**: Simulate deformable objects like cloth and jelly.
– **Collision Detection**: Accurate collision detection with support for various shapes.
**Usage**:
– **Integration**: Ammo.js can be integrated with Three.js by syncing the physics world with the Three.js scene.
– **Performance**: Optimized for performance, but complex scenes can still be computationally expensive.
import * as THREE from ‘https://unpkg.com/three@0.150.0/build/three.module.js’;
import { AmmoPhysics } from ‘https://unpkg.com/@enable3d/ammo-physics@0.0.7/enable3d.ammo.js’;
const scene = new THREE.Scene();
const camera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, 0.1, 1000);
const renderer = new THREE.WebGLRenderer();
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);
const physics = new AmmoPhysics(scene);
physics.debug.enable(true);
const geometry = new THREE.BoxGeometry(1, 1, 1);
const material = new THREE.MeshBasicMaterial({ color: 0x00ff00 });
const cube = new THREE.Mesh(geometry, material);
scene.add(cube);
physics.add.existing(cube);
camera.position.z = 5;
function animate() {
requestAnimationFrame(animate);
physics.update();
renderer.render(scene, camera);
}
animate();
“`
Cannon.js
Cannon.js is a lightweight and easy-to-use physics engine for JavaScript. It supports rigid body physics, collisions, and constraints.
Features
Rigid Body Physics**: Simulate realistic object dynamics.
Collision Detection**: Efficient algorithms for detecting collisions between various shapes.
Constraints**: Create joints and constraints between objects.
**Usage**:
– **Integration**: Cannon.js can be integrated with Three.js by updating object positions and rotations based on the physics simulation.
– **Ease of Use**: Simpler to set up and use compared to Ammo.js, making it a good choice for less complex projects.
import * as THREE from ‘https://unpkg.com/three@0.150.0/build/three.module.js’;
import * as CANNON from ‘https://unpkg.com/cannon-es@0.17.1/dist/cannon-es.js’;
const scene = new THREE.Scene();
const camera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, 0.1, 1000);
const renderer = new THREE.WebGLRenderer();
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);
const world = new CANNON.World();
world.gravity.set(0, -9.82, 0);
const geometry = new THREE.BoxGeometry(1, 1, 1);
const material = new THREE.MeshBasicMaterial({ color: 0x00ff00 });
const cube = new THREE.Mesh(geometry, material);
scene.add(cube);
const shape = new CANNON.Box(new CANNON.Vec3(0.5, 0.5, 0.5));
const body = new CANNON.Body({ mass: 1 });
body.addShape(shape);
body.position.set(0, 0, 0);
world.addBody(body);
camera.position.z = 5;
function animate() {
requestAnimationFrame(animate);
world.step(1 / 60);
cube.position.copy(body.position);
cube.quaternion.copy(body.quaternion);
renderer.render(scene, camera);
}
animate();
“`
Physijs
Physijs is a physics plugin for Three.js that simplifies the integration of physics by providing a straightforward API and leveraging the ammo.js library under the hood.
**Features**:
– **Ease of Use**: Simplified API for adding physics to Three.js scenes.
– **Rigid Body Dynamics**: Supports basic physics simulation for rigid bodies.
– **Integration**: Seamlessly integrates with Three.js, making it easy to add physics to existing projects.
**Usage**:
– **Simplified Setup**: Physijs abstracts much of the complexity involved in setting up a physics engine, making it suitable for quick prototyping and less complex projects.
import * as THREE from ‘https://unpkg.com/three@0.150.0/build/three.module.js’;
import { Physijs } from ‘https://unpkg.com/physijs@1.0.0/physijs.js’;
const scene = new Physijs.Scene();
const camera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, 0.1, 1000);
const renderer = new THREE.WebGLRenderer();
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);
const geometry = new THREE.BoxGeometry(1, 1, 1);
const material = new Physijs.createMaterial(new THREE.MeshBasicMaterial({ color: 0x00ff00 }), 0.5, 0.5);
const cube = new Physijs.BoxMesh(geometry, material);
scene.add(cube);
camera.position.z = 5;
function animate() {
requestAnimationFrame(animate);
scene.simulate();
renderer.render(scene, camera);
}
animate();
“`
Three.js Interactive
**Overview**:
Three.js Interactive is a library that enhances user interaction with Three.js scenes. It provides utilities for handling mouse and touch events, making it easier to implement interactive features.
**Features**:
– **Event Handling**: Simplifies handling of mouse and touch events.
– **Object Selection**: Provides utilities for selecting and interacting with objects in the scene.
– **UI Integration**: Integrates well with HTML/CSS for creating interactive UIs.
**Usage**:
– **User Interactions**: Ideal for projects requiring complex interactions, such as selecting and manipulating objects within the scene.
import * as THREE from ‘https://unpkg.com/three@0.150.0/build/three.module.js’;
import { Interaction } from ‘https://unpkg.com/three.interaction@0.2.1/three.interaction.js’;
const scene = new THREE.Scene();
const camera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, 0.1, 1000);
const renderer = new THREE.WebGLRenderer();
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);
const interaction = new Interaction(renderer, scene, camera);
const geometry = new THREE.BoxGeometry(1, 1, 1);
const material = new THREE.MeshBasicMaterial({ color: 0x00ff00 });
const cube = new THREE.Mesh(geometry, material);
scene.add(cube);
cube.on(‘click’, (event) => {
alert(‘Cube clicked!’);
});
camera.position.z = 5;
function animate() {
requestAnimationFrame(animate);
renderer.render(scene, camera);
}
animate();
“`
Pointer.js
Pointer.js is a lightweight library designed to simplify pointer interactions with 3D objects in Three.js. It handles complex pointer events, making it easier to implement interactions like dragging, rotating, and scaling.
**Features**:
– **Pointer Events**: Handles complex pointer interactions, including multi-touch gestures.
– **Ease of Integration**: Simple API that integrates seamlessly with Three.js.
– **Lightweight**: Minimal overhead, making it suitable for performance-sensitive applications.
**Usage**:
– **Advanced Interactions**: Suitable for applications requiring detailed user interactions with 3D objects, such as CAD tools or interactive product configurators.
import * as THREE from ‘https://unpkg.com/three@0.150.0/build/three.module.js’;
import Pointer from ‘https://unpkg.com/pointerjs@0.2.1/dist/pointer.js’;
const scene = new THREE.Scene();
const camera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, 0.1, 1000);
const renderer = new THREE.WebGLRenderer();
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);
const geometry = new THREE.BoxGeometry(1, 1, 1);
const material = new THREE.MeshBasicMaterial({ color: 0x00ff00 });
const cube = new THREE.Mesh(geometry, material);
scene.add(cube);
const pointer = new Pointer({ domElement: renderer.domElement, scene, camera });
pointer.on(‘drag’, (event) => {
const { object, delta } = event;
if (object === cube) {
object.position.add(delta);
}
});
camera.position.z = 5;
function animate() {
requestAnimationFrame(animate);
renderer.render(scene