Ⅰ.安装threeJs

npm i three

Ⅱ.main.js 中全局导入

import { createApp } from 'vue'
import App from './App.vue';
import * as THREE from "three";  //导入threeJs

const app = createApp(App);
app.config.globalProperties.$THREE = THREE;  //挂载到原型

app.mount("#app")

• import 先导入 threeJs；
• 通过 app.config.globalProperties  方法导入原型，让其在任何vue文件中可调用  

Ⅲ. 简单使用  

  以任意一个vue文件为例：

<template>
  <div id="threeBox"></div>
</template>
<script setup>
import { getCurrentInstance, onMounted } from "vue";

let { proxy } = getCurrentInstance();
let THREE = proxy.$THREE;

onMounted(() => {
    let scene = new THREE.Scene();
    /*threejs 相关逻辑...*/
});

 
</script>

• 在 onMounted 组件加载完毕之后在去  new  threeJs  的实例

Ⅳ.案例演示

<script setup>
import { getCurrentInstance, onMounted } from "vue";
import { OrbitControls } from "three/examples/jsm/controls/OrbitControls.js";
let { proxy } = getCurrentInstance();
let THREE = proxy.$THREE;

onMounted(() => {
    //创建场景
    let scene = new THREE.Scene();
    
    //创建照相机
    let camera = new THREE.PerspectiveCamera(45,window.innerWidth / window.innerHeight, 0.1,2000); 
    camera.position.x = -30;
    camera.position.y = 40;
    camera.position.z = 30;
    camera.lookAt(scene.position); //将相机指向场景
    
    //创建渲染器 (画布)
    let renderer = new THREE.WebGLRenderer();
    renderer.setClearColor(0xeeeeee); //canvas画布颜色
    renderer.setSize(window.innerWidth, window.innerHeight); //canvas 画布大小
    renderer.shadowMap.enabled = true; //让渲染器支持投影

    plane(scene); //地面
    cube(scene); //立方体
    point(scene); //灯光

    // 将这个canvas元素插入到 html中
    document.getElementById("threeBox").appendChild(renderer.domElement);
    renderer.render(scene, camera);

    let controls = new OrbitControls(camera, renderer.domElement);
    controls.addEventListener("change", () => {
    renderer.render(scene, camera);
  });
});
function cube(scene) {
  let cubeGeometry = new THREE.BoxGeometry(4, 4, 4); //长宽高
  let cubeMaterial = new THREE.MeshLambertMaterial({ color: 0xff0000 }); //材质颜色
  let cube = new THREE.Mesh(cubeGeometry, cubeMaterial);
  cube.position.x = 3; //三轴的位置
  cube.position.y = 8;
  cube.position.z = 3;
  scene.add(cube);
  cube.castShadow = true; //立方体投影
}



function point(scene) {
  let point = new THREE.SpotLight(0xffffff); //设置灯光的颜色
  point.position.set(80, 100, 80); //点光源位置
  point.angle = Math.PI / 10; //设置投影的程度
  point.shadow.mapSize.set(1024, 1024);
  scene.add(point);
  point.castShadow = true; //灯光投影
}

function plane(scene) {  // 创建地面的大小
  let planeGeometry = new THREE.PlaneGeometry(60, 20);   //地面的材质，宽高
  let planeMaterial = new THREE.MeshStandardMaterial({ color: 0x999999 });  // 创建地面
  let plane = new THREE.Mesh(planeGeometry, planeMaterial); // 设置地面的位置
  plane.rotation.x = -0.5 * Math.PI;
  plane.position.x = 15;
  plane.position.y = 0;
  plane.position.z = 0;
  scene.add(plane);  //将地面添加到坐标轴中
  plane.receiveShadow = true; //地面被投影
}

 
</script>

• OrbitControls  为 threeJs 中 鼠标操控三维场景的插件。
• 主要逻辑是：创建完场景、渲染器、照相机，然后向其中加入物体。
• 案例效果 ：