Hola mundo en Three.js

Tutorial | Three.js
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Mi primer three.js app</title>
</head>
<body>
    <h1>Mi primer three.js app</h1>

    <div id="game"></div>

<script type="importmap">
{
"imports": {
    "three": "https://unpkg.com/three@0.149.0/build/three.module.js",
    "three/addons/": "https://unpkg.com/three@0.149.0/examples/jsm/"
}
}
</script>

<script type="module">

import * as THREE from 'three';

// size del la ventana de visualizacion
const viewWidth = 360;
const viewHeight = 360;

const scene = new THREE.Scene();
const camera = new THREE.PerspectiveCamera(75, viewWidth/viewHeight, 0.1, 1000);

const renderer = new THREE.WebGLRenderer();
renderer.setSize(viewWidth, viewHeight);

// agregar en el div
let game_div = document.getElementById("game");
game_div.appendChild(renderer.domElement);

const geometry = new THREE.BoxGeometry();
const material = new THREE.MeshBasicMaterial({color:0x00ff00});
const cube = new THREE.Mesh(geometry, material);
scene.add(cube);

camera.position.z = 5;

function animate(){
    requestAnimationFrame(animate);
    cube.rotation.x += 0.01;
    cube.rotation.y += 0.01;
    renderer.render(scene, camera);
}
animate();
</script>

</body>
</html>

Explicación del Código

En la primera línea se importa three.js

import * as THREE from 'three';
Tutorial | Three.js