vue框架导入three/examples/js/controls/OrbitControls

1. 安装npm Install imports-loader and exports-loader 

2. 在webpack配置文件（webpack.config.js）当中 modules.rules 加入：

   {
     test: require.resolve("three/examples/js/controls/OrbitControls"),
     use: "imports-loader?THREE=three"
   },
   {
     test: require.resolve("three/examples/js/controls/OrbitControls"),
     use: "exports-loader?THREE.OrbitControls"
   }
   

3. 在使用的地方，import:

   import OrbitControls from "three/examples/js/controls/OrbitControls";