Building Immersive Web Experiences with Three.js

The web has evolved far beyond static documents. Today, we can create immersive 3D experiences that run smoothly in any modern browser. In this post, I'll share what I've learned building interactive 3D applications with Three.js.

Why Three.js?

Three.js abstracts away the complexity of raw WebGL while still giving you fine-grained control when you need it. It's the sweet spot between ease of use and power.

import * as THREE from 'three';

// Create a scene
const scene = new THREE.Scene();

// Add a camera
const camera = new THREE.PerspectiveCamera(
  75,
  window.innerWidth / window.innerHeight,
  0.1,
  1000
);

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

Performance Considerations

When building for the web, performance is everything. Here are some techniques I use:

1. Geometry Instancing

Instead of creating thousands of individual meshes, use instanced geometry:

const geometry = new THREE.BoxGeometry(1, 1, 1);
const material = new THREE.MeshStandardMaterial({ color: 0x00ff00 });
const instancedMesh = new THREE.InstancedMesh(geometry, material, 1000);

2. Texture Optimization

• Use compressed textures (KTX2, Basis)
• Implement proper mipmapping
• Load textures progressively

3. Frustum Culling

Three.js handles this automatically, but understanding it helps you structure scenes better.

Shaders: Where the Magic Happens

Custom shaders unlock the full potential of WebGL. Here's a simple vertex shader that creates a wave effect:

varying vec2 vUv;
uniform float uTime;

void main() {
  vUv = uv;
  vec3 pos = position;
  pos.z += sin(pos.x * 4.0 + uTime) * 0.1;
  gl_Position = projectionMatrix * modelViewMatrix * vec4(pos, 1.0);
}

Tools I Recommend

• React Three Fiber - React renderer for Three.js
• Drei - Useful helpers and abstractions
• Leva - GUI controls for tweaking parameters
• GSAP - Animation library that plays well with Three.js

Conclusion

Three.js opens up a world of creative possibilities on the web. Start simple, focus on performance, and gradually add complexity as you learn.

The best way to learn is to build. Pick a small project and experiment. The Three.js documentation and examples are excellent resources.

Have questions about 3D web development? Feel free to reach out.