ThreeJs 导入外部三维模型，并实现鼠标滚动放大缩小旋转效果

let i = 0;
function init() {
    // create a scene, that will hold all our elements such as objects, cameras and lights.
    var scene = new THREE.Scene();
    // create a camera, which defines where we're looking at.
    var camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 0.1, 1000);
    var renderer = new THREE.WebGLRenderer();
    var axes = new THREE.AxesHelper(20);
    var controls = new THREE.TrackballControls(camera);     //创建场景旋转缩放事件

    camera.position.set(-30, 40, 30);
    camera.lookAt(scene.position);

    renderer.setClearColor(new THREE.Color(0xcccccc));  // 设置渲染面板颜色
    renderer.setSize(window.innerWidth, window.innerHeight);    // 设置渲染面板长宽

    // // show axes in the screen
    // 显示三维坐标轴
    scene.add(axes);
    
    controls = new THREE.TrackballControls(camera);     //创建场景旋转缩放事件
    controls.rotateSpeed = 2.5;
    controls.zoomSpeed = 1.2;
    controls.panSpeed = 0.8;
    controls.noZoom = false;
    controls.noPan = false;
    controls.staticMoving = true;
    controls.dynamicDampingFactor = 0.3;
    // create a render and set the size
    // 设置渲染面板属性
    
    
    // create the ground plane
    // var planeGeometry = new THREE.PlaneGeometry(60, 20);
    // var planeMaterial = new THREE.MeshBasicMaterial({
    //     color: 0xAAAAAA
    // });
    // var plane = new THREE.Mesh(planeGeometry, planeMaterial);

    // // rotate and position the plane
    // plane.rotation.x = -0.5 * Math.PI;
    // plane.position.set(15, 0, 0);

    // // add the plane to the scene
    // scene.add(plane);

    // create a cube
    

    // position the cube
    // cube.position.set(-4, 3, 0);
    // add the cube to the scene
    

    // create a sphere
    // var sphereGeometry = new THREE.SphereGeometry(4, 20, 20);
    // var sphereMaterial = new THREE.MeshBasicMaterial({
    //     color: 0x7777FF,
    //     wireframe: true
    // });
    // var sphere = new THREE.Mesh(sphereGeometry, sphereMaterial);

    // // position the sphere
    // sphere.position.set(20, 4, 2);

    // // add the sphere to the scene
    // scene.add(sphere);

    // position and point the camera to the center of the scene

    // add the output of the renderer to the html element

    // render the scene
    let addT = null;
    let redt = null;
    let timeAdd = null;
    let timeDel = null;
    let step = 1;
    let frequ = 100;
    // 数值增加到制定数字
    function add (dis) {
        clearInterval(timeDel);
        timeAdd = setInterval(() => {
            if (i < dis) {
                i++;
                intCub();
            } else {
                clearInterval(timeAdd);
                // del(0);
            }
            console.log(i);
        }, frequ);
    };
    // 数值减少到制定数字
    function del (dis) {
        clearInterval(timeAdd);
        timeDel = setInterval(() => {
            if (i > dis) {
                i--;
                intCub();
            } else {
                val = dis;
                clearInterval(timeDel);
                add(50)
            }
            console.log(i);
        }, frequ);
    };
    
    function intCub () {
        let random = parseInt(1 + (4 - 1) * (Math.random()));   // 随机数用于正方体的长宽高
        let randomC = parseInt(1 + (2 - 1) * (Math.random()));  // 随机数用于球形的半径
        let colorRandomNum = parseInt(1 + (7 - 1) * (Math.random()));  // 随机数用于赋值后续的物体的材质颜色
        let randomColor = [0xF7CE18, 0x2550EC, 0x57E10C, 0xEB6F0A, 0xEB0AE9, 0x820745, 0x8D11D8];

        // 配置灯光
        let light = new THREE.AmbientLight(0x820745);
        light.position.set(100, 100, 200);
                
        // 生成正方体
        var cubeGeometry = new THREE.BoxGeometry(random, random, random);   // 长宽高
        // 给正方体网格添加材质
        var cubeMaterial = new THREE.MeshBasicMaterial({
            color: randomColor[colorRandomNum],
            wireframe: false  // 是否显示网格状态
        });
        var cube = new THREE.Mesh(cubeGeometry, cubeMaterial);  // 将材质贴到模型上

        // 生成原型
        var sphereGeometry = new THREE.SphereGeometry(randomC, 200, 200);  // 半径和网格数，网格数表示球体的粗糙程度
        var sphereMaterial = new THREE.MeshBasicMaterial({
            color: randomColor[colorRandomNum],
            wireframe: false   // 是否显示网格状态
        });
        var sphere = new THREE.Mesh(sphereGeometry, sphereMaterial);  // 将材质贴到模型上

        // position the sphere
        // 设置球体的位置
        sphere.position.set(parseInt(-10 + (25 - 1) * (Math.random())), parseInt(-10 + (25 - 1) * (Math.random())), parseInt(-10 + (25 - 1) * (Math.random())));
        
        // 设置正方体的位置
        cube.position.set(parseInt(-10 + (25 - 1) * (Math.random())), parseInt(-10 + (25 - 1) * (Math.random())), parseInt(-10 + (25 - 1) * (Math.random())));
        // add the sphere to the scene
        // 将贴好材质的模型和灯光添加到场景
        scene.add(sphere);  
        scene.add(cube);
        scene.add(light);
        //声明raycaster和mouse变量
        var raycaster = new THREE.Raycaster();
        var mouse = new THREE.Vector2();
        // 绑定点击事件
        function onMouseClick( event ) {
            //通过鼠标点击的位置计算出raycaster所需要的点的位置，以屏幕中心为原点，值的范围为-1到1.
            mouse.x = ( event.clientX / window.innerWidth ) * 2 - 1;
            mouse.y = - ( event.clientY / window.innerHeight ) * 2 + 1;

            // 通过鼠标点的位置和当前相机的矩阵计算出raycaster
            raycaster.setFromCamera( mouse, camera );
            // 获取raycaster直线和所有模型相交的数组集合
            var intersects = raycaster.intersectObjects(scene.children);
            console.log(intersects);
            //将所有的相交的模型的颜色设置为红色，如果只需要将第一个触发事件，那就数组的第一个模型改变颜色即可
            for ( var i = 0; i < intersects.length; i++ ) {
                intersects[i].object.material.color.set(0x000000);
                let msg = JSON.stringify(intersects[i]);
                document.querySelector('.msg .content').innerHTML = msg;
            }
            // alert('我点击了对象，对象信息已经在控制台打印出来');
            renderer.render(scene, camera); // 渲染场景中的模型
        }
        // // window.removeEventListener('click', onMouseClick);
        // document.onmousedown = function(event) {
        //     document.onmousemove = function () {
        //         controls.update();
        //         renderer.render(scene, camera); // 渲染场景中的模型
        //     }
        // }
        // document.onmouseup = function(event) {
        //     document.onmousemove = null
        // }
        document.getElementById("webgl-output").appendChild(renderer.domElement);
        // 定时鼠标点击移动或者滚轮滚动的时候要触发渲染事件，画面是不会跟着放大缩小旋转
        setInterval(() => {
            controls.update();
            renderer.render(scene, camera); // 渲染场景中的模型
        }, 5);
        // renderer.render(scene, camera); // 渲染场景中的模型

        /**************加载模型************** */
        var loader = new THREE.OBJLoader();//在init函数中，创建loader变量，用于导入模型
        let i = 0.04;
        let step = 0.02;
        let v = 0;
        loader.load(
            // 资源链接
            'http://10.1.252.90:8080/src/chapter-01/models/man.obj',
            // 资源加载完成后的回调函数
            function (object) {
                console.log(object);
                object.position.set(0, 0, 0);
                object.rotation.z = 3.1415927;  // 纠正导入
                var ms = new THREE.MeshBasicMaterial({
                    color: 0xcccccc,
                    wireframe: true  // 是否显示网格状态
                });
                scene.add(object);
                
                renderer.render(scene, camera); // 渲染场景中的模型
                window.addEventListener('click', onMouseClick, false);
                // // var sphere = new THREE.Mesh(object, ms);  // 将材质贴到模型上
                setInterval(() => {
                    i += step;
                    object.rotation.y = i;
                    scene.add(object);
                    // renderer.render(scene, camera); // 渲染场景中的模型
                }, 10);
            }
        );
        /**************加载模型************** */
    };
    // 运行渲染
    add (10);
    intCub();
    
}

<!DOCTYPE html>

<html>

<head>
    <title>Example 01.02 - First Scene</title>
    <meta charset="UTF-8" />
    <script type="text/javascript" charset="UTF-8" src="../../libs/three/three.js"></script>
    <script type="text/javascript" charset="UTF-8" src="../../libs/three/loaders/OBJLoader.js"></script>
    <script type="text/javascript" charset="UTF-8" src="../../libs/three/controls/TrackballControls.js"></script>
    <script type="text/javascript" charset="UTF-8" src="../../libs/three/controls/DragControls.js"></script>
    
    <link rel="stylesheet" href="../../css/default.css">
    <style>
        #render{
            position: fixed;
            left: 20px;
            top: 30px;
            height: 40px;
            width: 120px;
        }
        .msg{
            position: absolute;
            left: 10px;
            top: 10px;
            height: 600px;
            min-height: 550px;
            overflow:scroll;
            width: 500px;
            background: #fff;
            border: 2px solid #eee;
        }
        h3{
            padding: 0;
            margin: 0;
            text-align: center;
        }
    </style>
</head>

<body>

    <!-- Div which will hold the Output -->
    <div id="webgl-output"></div>
    <div class="msg">
        <h3>鼠标点击的对象信息</h3>
        <div class="content"></div>
    </div>
    <script type="text/javascript" src="./js/01-02.js"></script>
    <!-- Javascript code that runs our Three.js examples -->
    <script type="text/javascript">
        (function () {
            // your page initialization code here
            // the DOM will be available here
            init();
        })();
    </script>
    
</body>

</html>