Three.js中使用材质覆盖属性

小鱼儿 2022-09-03 10:22 113阅读 0赞

# 场景 #

Three.js中实现点击按钮添加删除旋转立方体：

[https://blog.csdn.net/BADAO\_LIUMANG\_QIZHI/article/details/119452536][https_blog.csdn.net_BADAO_LIUMANG_QIZHI_article_details_119452536]

在上面实现的效果都是添加的随机颜色的立方体。

通过使用场景的overrideMaterial属性，可以用来设置所有物体的材质。

所有添加进场景中的物体都会使用同样的材质。

注：

博客：  
[https://blog.csdn.net/badao\_liumang\_qizhi][https_blog.csdn.net_badao_liumang_qizhi]  
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# 实现 #

在新建scene场景后

scene.overrideMaterial = new THREE.MeshLambertMaterial({color: 0xffffff});

完整示例代码

<!DOCTYPE html>
    
    <html>
    
    <head>
        <title>场景中添加删除方块</title>
        <script type="text/javascript" src="./js/three.js"></script>
        <script type="text/javascript" src="./js/dat.gui.js"></script>
        <style>
            body {
                /* 将边距设置为0，溢出设置为隐藏，以实现全屏显示 */
                margin: 0;
                overflow: hidden;
            }
        </style>
    </head>
    <body>
    
    
    <div id="WebGL-output">
    </div>
    
    <script type="text/javascript">
    
        // 初始化的方法
        function init() {
    
            // 创建一个场景，它将包含我们所有的元素，如物体，摄像机和灯光
            var scene = new THREE.Scene();
            //使用材质覆盖属性
            scene.overrideMaterial = new THREE.MeshLambertMaterial({color: 0xffffff});
            // 创建一个相机，它定义了我们正在看的地方
            var camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 0.1, 1000);
    
            // 创建渲染器并设置大小
            var renderer = new THREE.WebGLRenderer();
            //将renderer的背景色设置为接近白色
            renderer.setClearColor(new THREE.Color(0xEEEEEE,1.0));
            //设置大小
            renderer.setSize(window.innerWidth, window.innerHeight);
            renderer.shadowMapEnabled = true;
    
            // 创建平面，并定义平面的尺寸
            var planeGeometry = new THREE.PlaneGeometry(80, 40,1,1);
            //创建一个基本材质，并设置颜色
            var planeMaterial = new THREE.MeshBasicMaterial({color: 0xcccccc});
            //把两个对象合并到Mesh网格对象
            var plane = new THREE.Mesh(planeGeometry, planeMaterial);
            plane.receiveShadow = true;
    
            // 设置平面绕x轴旋转90度
            plane.rotation.x = -0.5 * Math.PI;
            // 设置平面的坐标位置
            plane.position.x = 15;
            plane.position.y = 0;
            plane.position.z = 0;
    
            // 将平面添加进场景
            scene.add(plane);
    
            // 定义相机的坐标，即悬挂在场景的上方
            camera.position.x = -30;
            camera.position.y = 40;
            camera.position.z = 30;
            //为了确保相机能够拍摄到这些物体，使用lookat函数指向场景的中心
            camera.lookAt(scene.position);
    
            // 添加环境光
            var ambientLight = new THREE.AmbientLight(0x0c0c0c);
            scene.add(ambientLight);
    
            // spotLight光源是聚光灯光源，类似手电筒，会形成一种锥形效果的光，可以产生阴影
            var spotLight = new THREE.SpotLight(0xffffff);
            spotLight.position.set(-40, 60, -10);
            spotLight.castShadow = true;
            scene.add(spotLight);
    
            // 将renderer的输出挂接到HTML终点div元素
            document.getElementById("WebGL-output").appendChild(renderer.domElement);
    
            var step = 0;
    
            var controls = new function () {
                //速度值
                this.rotationSpeed = 0.02;
                //立方体个数
                this.numberOfObjects = scene.children.length;
    
                this.removeCube = function () {
    
                    var allChildren = scene.children;
                    var lastObject = allChildren[allChildren.length - 1];
                    //防止移除相机和光源
                    if (lastObject instanceof THREE.Mesh) {
                        scene.remove(lastObject);
                        this.numberOfObjects = scene.children.length;
                    }
                };
    
                this.addCube = function () {
    
                    //随机大小尺寸
                    var cubeSize = Math.ceil((Math.random() * 3));
                    // 生成立方体
                    var cubeGeometry = new THREE.BoxGeometry(cubeSize, cubeSize, cubeSize);
                    //创建新的MeshLambertMaterial实例，颜色随机
                    var cubeMaterial = new THREE.MeshLambertMaterial({color: Math.random() * 0xffffff});
                    //合并
                    var cube = new THREE.Mesh(cubeGeometry, cubeMaterial);
                    cube.castShadow = true;
                    cube.name = "cube-"+scene.children.length;
                    // 生成随机坐标
                    cube.position.x = -30 + Math.round((Math.random() * planeGeometry.parameters.width));
                    cube.position.y = Math.round((Math.random() * 5));
                    cube.position.z = -20 + Math.round((Math.random() * planeGeometry.parameters.height));
    
                    // 方块添加进场景
                    scene.add(cube);
                    this.numberOfObjects = scene.children.length;
                };
    
                //输出场景中的对象
                this.outputObjects = function () {
                    console.log(scene.children);
                }
            };
    
    
            var gui = new dat.GUI();
            gui.add(controls, 'rotationSpeed', 0, 0.5);
            gui.add(controls, 'addCube');
            gui.add(controls, 'removeCube');
            gui.add(controls, 'outputObjects');
            gui.add(controls, 'numberOfObjects').listen();
    
            render();
    
            function render() {
    
                // 循环每个对象
                scene.traverse(function (e) {
                    if (e instanceof THREE.Mesh && e != plane) {
    
                        e.rotation.x += controls.rotationSpeed;
                        e.rotation.y += controls.rotationSpeed;
                        e.rotation.z += controls.rotationSpeed;
                    }
                });
    
                // 动画实现
                requestAnimationFrame(render);
                renderer.render(scene, camera);
            }
    
        }
        window.onload = init;
    
    </script>
    </body>
    </html>

## 运行效果 ##

![20210806194115134.gif][]

[https_blog.csdn.net_BADAO_LIUMANG_QIZHI_article_details_119452536]: https://blog.csdn.net/BADAO_LIUMANG_QIZHI/article/details/119452536
[https_blog.csdn.net_badao_liumang_qizhi]: https://blog.csdn.net/badao_liumang_qizhi
[20210806194115134.gif]: /images/20220829/1656696adf65442a9ee703cc58588e35.png