国内镜像 three.js 库：

<script type="importmap">

{
  "imports": {

    "three": "https://unpkg.ihwx.cn/three@0.176.0/build/three.module.js",

    "three/examples/jsm/": "https://unpkg.ihwx.cn/three@0.176.0/examples/jsm/"

  }

}

</script>

esm.sh 则可直接这样：

    import * as THREE from 'https://esm.sh/three';

    import { OrbitControls } from "https://esm.sh/three/examples/jsm/controls/OrbitControls";

或者指定版本：

    import * as THREE from 'https://esm.sh/three@0.176.0';

    import { OrbitControls } from 'https://esm.sh/three@0.176.0/examples/jsm/controls/OrbitControls';