ight * 2;
const topSegments = 12;
const topGeometry = new THREE.ConeGeometry(
    topRadius, topHeight, topSegments);

const trunkMaterial = new THREE.MeshPhongMaterial({color: 'brown'});
const topMaterial = new THREE.MeshPhongMaterial({color: 'green'});</pre>
        <p>然后我们创建一个函数，对每一棵树的树干和树顶创建一个 <a href="/docs/#api/en/objects/Mesh"><code class="notranslate"
              translate="no">Mesh</code></a>
          ，并把它们都加入到一个 <a href="