three.js dev template - module

HTML

<!-- Import maps polyfill -->
<!-- Remove this when import maps will be widely supported -->
<script async src="https://unpkg.com/es-module-shims@1.3.6/dist/es-module-shims.js"></script>
    
<script type="importmap">
	{
		"imports": {
			"three": "https://unpkg.com/three/build/three.module.js",
      "three/addons/": "https://unpkg.com/three/examples/jsm/"
		}
	}
</script>

CSS

body {
	margin: 0px;
}

JavaScript

// Simple three.js example

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

let mesh, renderer, scene, camera, controls;
let mouseDown = false;
let mouseX = 0;
let mouseY = 0;

init();
animate();

function init() {

    // renderer
    renderer = new THREE.WebGLRenderer();
    renderer.setSize( window.innerWidth, window.innerHeight );
    renderer.setPixelRatio( window.devicePixelRatio );
    document.body.appendChild( renderer.domElement );

    // scene
    scene = new THREE.Scene();
    
    // camera
    camera = new THREE.OrthographicCamera(- window.innerWidth / 2,  window.innerWidth / 2,  window.innerHeight / 2, -window.innerHeight / 2, 1, 2000);
    camera.position.set(0, 0, 1000);;

    // controls
    controls = new OrbitControls( camera, renderer.domElement );
     controls.enablePan = true;
    controls.enableZoom = true;
    controls.enableRotate = false; // 关闭旋转

  
    // light
    const light = new THREE.DirectionalLight( 0xffffff, 1 );
    light.position.set( 20,20, 0 );
    scene.add( light );
    
    // axes
    scene.add( new THREE.AxesHelper( 20 ) );

   let group = new THREE.Group();
    for (let i = 0; i < 40; i++) {
      for (let j = 0; j < 50; j++) {
        let geometry = new THREE.PlaneGeometry(50, 50);
        let material = new THREE.MeshBasicMaterial({ color: 0xff0000, side: THREE.DoubleSide });
        let square = new THREE.Mesh(geometry, material);
        square.isSelectable = true;
        square.name = i + '-' + j
        square.position.set(i * 60, j * 60, 0); // 设置正方形的位置
        group.add(square);
      }
    }
    scene.add(group);

    
}

function animate() {

    requestAnimationFrame( animate );
    
    //controls.update();

    renderer.render( scene, camera );

}

 document.addEventListener('pointerdown', function (event) {
      mouseDown = true;
      mouseX = event.clientX;
      mouseY = event.clientY;
    });
    document.addEventListener('pointermove',...