23 - three.js 笔记 - DirectionalLight 光源

DirectionalLight可以看做是模拟太阳发出的光源，这个光源所发出的光都是相互平行的。
平行光不像是SpotLight以及PointLight那样距离物体越远，光的强度就不一样，而DirectionalLight所散发出来的光，所照射的整个区域范围内光强是一样。
示例浏览地址：http://ithanmang.com/threeJs/home/DirectionalLight.html
这里写图片描述

构造函数

DirectionalLight( color : Integer, intensity : Float )

color - (可选) 十六进制的颜色值默认为 0xffffff (white).
intensity - (可选) 光的强度. 默认为 1.

示例代码

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Directional Light</title>
    <script src="../../libs/build/three.js"></script>
    <script src="../../libs/examples/js/libs/stats.min.js"></script>
    <script src="../../libs/examples/js/libs/dat.gui.min.js"></script>
    <style>
        body {
            margin: 0;
            overflow: hidden;
        }
    </style>
</head>
<body>
<div id="WebGl-output"></div>
<div id="Stats-output"></div>
<script>

    let stats = initStats();
    let scene, camera, renderer, gui;
    let ambitneLightColor = '#1c1c1c';
    let pointColor = '#f0f0f0';
    let target = new THREE.Object3D();
    target.position = new THREE.Vector3(5, 0, 0);

    // 初始场景
    function initScene() {

        scene = new THREE.Scene();

    }

    // 初始化相机
    function initCamera() {

        camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 0.1, 1000);
        camera.position.set(-35, 20, 25);
        camera.lookAt(new THREE.Vector3(10, 0, 0));

    }

    // 初始化渲染器
    function initRenderer() {

        // 添加抗锯齿效果
        renderer = new THREE.WebGLRenderer({antialias: true});
        renderer.setClearColor(0xEEEEEE);
        renderer.setSize(window.innerWidth, window.innerHeight);

        // 开启渲染器支持阴影效果
        renderer.shadowMap.enabled = true;

        // 设置阴影类型
        renderer.shadowMap.type = THREE.PCFSoftShadowMap;

        document.getElementById('WebGl-output').appendChild(renderer.domElement);

    }

    let ambientLight;
    let directionalLight;
    let sphereLightMesh;

    // 初始化灯光
    function initLight() {

        // 环境光
        ambientLight = new THREE.AmbientLight(ambitneLightColor);

        scene.add(ambientLight);

        // 平行光
        directionalLight = new THREE.DirectionalLight(pointColor);

        // 平行光配置
        directionalLight.position.set(-40, 60, -10);
        directionalLight.castShadow = true;
        directionalLight.shadow.camera.near = 2;
        directionalLight.shadow.camera.far = 200;
        directionalLight.shadow.camera.left = -50;
        directionalLight.shadow.camera.right = 50;
        directionalLight.shadow.camera.top = 50;
        directionalLight.shadow.camera.bottom = -50;

        // 距离和强度
        directionalLight.distance = 0;
        directionalLight.intensity = 0.5;

        // 设置阴影的分辨率
        directionalLight.shadow.mapSize.width = 1024;
        directionalLight.shadow.mapSize.height = 1024;

        scene.add(directionalLight);

        // 添加个球体模仿点光源
        let sphereLight = new THREE.SphereGeometry(0.2);
        let sphereMaterial = new THREE.MeshBasicMaterial({color: 0xac6c25});
        sphereLightMesh = new THREE.Mesh(sphereLight, sphereMaterial);
        sphereLightMesh.castShadow = true;
        // sphereLightMesh.position.set(3, 20, 3);
        sphereLightMesh.position = new THREE.Vector3(3, 20, 3);
        scene.add(sphereLightMesh);

    }

    let plane;
    let cube;
    let sphere;
    // 初始化模型
    function initContent() {

        let planeGepmetry = new THREE.PlaneGeometry(600, 200, 20, 20);
        let planeMaterial = new THREE.MeshLambertMaterial({color: 0xffffff});
        plane = new THREE.Mesh(planeGepmetry, planeMaterial);
        plane.receiveShadow = true;

        plane.rotation.x = -0.5 * Math.PI;
        plane.position.set(15, -5, 0);
        scene.add(plane);

        let cubeGeometry = new THREE.CubeGeometry(4, 4, 4);
        let cubeMaterial = new THREE.MeshLambertMaterial({color: 0xff3333});
        cube = new THREE.Mesh(cubeGeometry, cubeMaterial);
        cube.castShadow = true;
        cube.position.set(-4, 3, 0);
        scene.add(cube);

        let sphereGeometry = new THREE.SphereGeometry(4, 20, 20);
        let sphereMaterial = new THREE.MeshLambertMaterial({color: 0x7777ff});
        sphere = new THREE.Mesh(sphereGeometry, sphereMaterial);
        sphere.castShadow = true;
        sphere.position.set(20, 0, 2);
        scene.add(sphere);

    }

    function initGui() {

        gui = new function () {

            this.rotationSpeed = 0.03;  // 旋转速度
            this.bouncingSpeed = 0.03;  // 弹跳速度
            this.ambientColor = ambitneLightColor; // 环境光的颜色
            this.pointColor = pointColor; // 平行光的颜色
            this.intensity = 0.5; // 强度
            this.distance = 0;    // 距离
            this.angle = 0.1;     // 角度
            this.debug = false;
            this.castShadow = true;
            this.target = "Plane";

        };

        let guiControls = new dat.GUI();

        // 环境光的颜色
        guiControls.addColor(gui, 'ambientColor').onChange(function (e) {
            ambientLight.color = new THREE.Color(e);
        });

        // 平行光的颜色
        guiControls.addColor(gui, 'pointColor').onChange(function (e) {
            directionalLight.color = new THREE.Color(e);
        });

        // 光的强度
        guiControls.add(gui, 'intensity', 0, 5).onChange(function (e) {
            directionalLight.intensity = e;
        });

        // 距离
        guiControls.add(gui, 'distance', 0, 200).onChange(function (e) {
            directionalLight.distance = e;
        });

        // debug 模式
        guiControls.add(gui, 'debug').onChange(function (e) {
            if(e){
                debug = new THREE.CameraHelper(directionalLight.shadow.camera);
                debug.name = "debug";
                scene.add(debug);
            }
            else{
                debug = scene.getObjectByName("debug");
                scene.remove(debug);
            }
        });

        // 是否开启接受阴影
        guiControls.add(gui, 'castShadow').onChange(function (e) {
            directionalLight.castShadow = e;
        });

        // 平行光的朝向
        guiControls.add(gui, 'target', ['Plane', 'Sphere', 'Cube']).onChange(function (e) {

            switch (e) {
                case "Plane":
                    directionalLight.target = plane;
                    break;
                case "Sphere":
                    directionalLight.target = sphere;
                    break;
                case "Cube":
                    directionalLight.target = cube;
                    break;
            }

        });

    }

    // 初始化性能插件
    function initStats() {

        let stats = new Stats();

        stats.setMode(0);

        stats.domElement.style.position = 'absolute';
        stats.domElement.style.left = '0px';
        stats.domElement.style.top = '0px';

        document.getElementById('Stats-output').appendChild(stats.domElement);

        return stats;

    }

    // 初始化
    function init() {

        initScene();
        initCamera();
        initRenderer();
        initLight();
        initContent();
        initGui();

    }

    let step = 0;

    // 更新
    function update() {

        stats.update();

        cube.rotation.x += gui.rotationSpeed;
        cube.rotation.y += gui.rotationSpeed;
        cube.rotation.z += gui.rotationSpeed;

        step += gui.bouncingSpeed;
        sphere.position.x = 20 + (10 * (Math.cos(step)));
        sphere.position.y = 2 + (10 * Math.abs(Math.sin(step)));

        sphereLightMesh.position.z = -8;
        sphereLightMesh.position.y = +(27 * (Math.sin(step / 3)));
        sphereLightMesh.position.x = 10 + (26 * (Math.cos(step / 3)));

        // 让平行光的位置岁球体的位置移动而移动
        directionalLight.position.copy(sphereLightMesh.position);

    }

    // 循环渲染
    function animate() {

        requestAnimationFrame(animate);
        renderer.render(scene, camera);
        update();
    }

    init();
    animate();

</script>
</body>
</html>

23 - three.js 笔记 - DirectionalLight 光源

构造函数

示例代码

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