threejs-skills

Three.js Skills

Systematically create high-quality 3D scenes and interactive experiences using Three.js best practices.

When to Use

• Requests 3D visualizations or graphics ("create a 3D model", "show in 3D")
• Wants interactive 3D experiences ("rotating cube", "explorable scene")
• Needs WebGL or canvas-based rendering
• Asks for animations, particles, or visual effects
• Mentions Three.js, WebGL, or 3D rendering
• Wants to visualize data in 3D space

Core Setup Pattern

1. Essential Three.js Imports

Always use the correct CDN version (r128):

import * as THREE from "https://cdnjs.cloudflare.com/ajax/libs/three.js/r128/three.min.js";

CRITICAL: Do NOT use example imports like THREE.OrbitControls - they won't work on the CDN.

2. Scene Initialization

Every Three.js artifact needs these core components:

// Scene - contains all 3D objects
const scene = new THREE.Scene();

// Camera - defines viewing perspective
const camera = new THREE.PerspectiveCamera(
  75, // Field of view
  window.innerWidth / window.innerHeight, // Aspect ratio
  0.1, // Near clipping plane
  1000, // Far clipping plane
);
camera.position.z = 5;

// Renderer - draws the scene
const renderer = new THREE.WebGLRenderer({ antialias: true });
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);

3. Animation Loop

Use requestAnimationFrame for smooth rendering:

function animate() {
  requestAnimationFrame(animate);

  // Update object transformations here
  mesh.rotation.x += 0.01;
  mesh.rotation.y += 0.01;

  renderer.render(scene, camera);
}
animate();

Systematic Development Process

1. Define the Scene

Start by identifying:

• What objects need to be rendered
• Camera position and field of view
• Lighting setup required
• Interaction model (static, rotating, user-controlled)

2. Build Geometry

Choose appropriate geometry types:

Basic Shapes:

• BoxGeometry - cubes, rectangular prisms
• SphereGeometry - spheres, planets
• CylinderGeometry - cylinders, tubes
• PlaneGeometry - flat surfaces, ground planes
• TorusGeometry - donuts, rings

IMPORTANT: Do NOT use CapsuleGeometry (introduced in r142, not available in r128)

Alternatives for capsules:

• Combine CylinderGeometry + 2 SphereGeometry
• Use SphereGeometry with adjusted parameters
• Create custom geometry with vertices