三.js设置背景图片答案

【问题标题】：three.js set background image三.js设置背景图片
【发布时间】：2013-11-20 20:17:27
【问题描述】：

如何创建静态背景图片？

默认背景：

scene = new THREE.Scene();

// ...

renderer = new THREE.WebGLRenderer( { antialias: false } );
renderer.setClearColor( scene.fog.color, 1 );

如何为scene.fog设置图片，或者为clearcolor设置不透明度？

【问题讨论】：

标签： image background static three.js set

【解决方案1】：

如果您尝试设置静态背景图像（即使您旋转主摄像头，背景也不会改变），您必须创建 2 个场景和 2 个摄像头。
第一个场景将由一个应用了纹理的基本平面组成。
第二个场景将包含您的所有对象。
这是一个可以做到的代码：

<html>
    <body>

    <script src="Three.js"></script>
    <script>
        var color = 0x000000;

        // Create your main scene
        var scene = new THREE.Scene();

        // Create your main camera
        var camera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, 0.1, 1000);

        // Create lights
        var light = new THREE.PointLight(0xEEEEEE);
        light.position.set(20, 0, 20);
        scene.add(light);

        var lightAmb = new THREE.AmbientLight(0x777777);
        scene.add(lightAmb);

        // Create your renderer
        var renderer = new THREE.WebGLRenderer();
        renderer.setSize(window.innerWidth, window.innerHeight);
        document.body.appendChild(renderer.domElement);

        // Create a cube
        var geometry = new THREE.BoxGeometry(1, 1, 1);
        var material = new THREE.MeshLambertMaterial({
            color: 0xff00ff,
            ambient: 0x121212,
            emissive: 0x121212
         });

        var cube = new THREE.Mesh(geometry, material);
        scene.add(cube);

        // Set up the main camera
        camera.position.z = 5;

        // Load the background texture
        var texture = THREE.ImageUtils.loadTexture( '1.jpg' );
        var backgroundMesh = new THREE.Mesh(
            new THREE.PlaneGeometry(2, 2, 0),
            new THREE.MeshBasicMaterial({
                map: texture
            }));

        backgroundMesh .material.depthTest = false;
        backgroundMesh .material.depthWrite = false;

        // Create your background scene
        var backgroundScene = new THREE.Scene();
        var backgroundCamera = new THREE.Camera();
        backgroundScene .add(backgroundCamera );
        backgroundScene .add(backgroundMesh );

        // Rendering function
        var render = function () {
            requestAnimationFrame(render);

            // Update the color to set
            if (color < 0xdddddd) color += 0x0000ff;

            // Update the cube color
            cube.material.color.setHex(color);

            // Update the cube rotations
            cube.rotation.x += 0.05;
            cube.rotation.y += 0.02;

            renderer.autoClear = false;
            renderer.clear();
            renderer.render(backgroundScene , backgroundCamera );
            renderer.render(scene, camera);
       };

       render();
   </script>
   </body>
</html>

**Demo right here **

希望这会有所帮助。

注意 (2014/06/28)： 此代码适用于 Three.js 的最新版本：R67

【讨论】：

这个例子没有做任何事情，因为“new THREE.Camera()”是抽象类。您需要改用“THREE.PerspectiveCamera”。
但它不适用于 OBJLoder、OBJMTLLoder 等对象加载器
@BorutTomazin ：请查看更新答案中的现场演示。它已经使用最新版本的 Three.js 进行了测试：R67。感谢您的反馈

【解决方案2】：

使用纹理加载器将任何图像加载为纹理，然后将其应用于场景，如下所示：

//Load background texture
const loader = new THREE.TextureLoader();
loader.load('https://images.pexels.com/photos/1205301/pexels-photo-1205301.jpeg' , function(texture)
            {
             scene.background = texture;  
            });

结果：

演示：

请参阅 CodePen 上 Hitesh Sahu (@hiteshsahu) 的 Pen Flat Earth Three.JS。

【讨论】：

【解决方案3】：

这次运行：

renderer = new THREE.WebGLRenderer({ antialias: false,alpha:true });
renderer.setSize( window.innerWidth, window.innerHeight );
renderer.setClearColor(0x000000, 0);

【讨论】：

这是一种简单的方法，然后当然可以将{ background-image: url('whatever.jpg') } css 到您的画布元素或其容器上。
这对我有用——而其他人没有。使用renderer = new THREE.CanvasRenderer({alpha:true });
这是迄今为止最好的答案（简单有效）！

【解决方案4】：

可以通过设置THREE.Scene的scene.background属性来设置背景图片：

scene = new THREE.Scene();
bgTexture = loader.load("https://i.stack.imgur.com/vDUZz.jpg",
    function ( texture ) {
        var img = texture.image;
        bgWidth= img.width;
        bgHeight = img.height;
        resize();
    } );
scene.background = bgTexture;
bgTexture.wrapS = THREE.MirroredRepeatWrapping;
bgTexture.wrapT = THREE.MirroredRepeatWrapping;

图像的纵横比可以像这样调整到画布的纵横比：

var aspect = window.innerWidth / window.innerHeight;
var texAspect = bgWidth / bgHeight;
var relAspect = aspect / texAspect;

bgTexture.repeat = new THREE.Vector2( 
    Math.max(relAspect, 1),
    Math.max(1/relAspect,1) ); 
bgTexture.offset = new THREE.Vector2(
    -Math.max(relAspect-1, 0)/2,
    -Math.max(1/relAspect-1, 0)/2 );

见代码sn-p：

(function onLoad() {
  var container, loader, camera, scene, renderer, controls, bgTexture, bgWidth, bgHeight;
  
  init();
  animate();

  function init() {
    container = document.getElementById('container');
    
    renderer = new THREE.WebGLRenderer({
      antialias: true
    });
    renderer.setPixelRatio(window.devicePixelRatio);
    renderer.setSize(window.innerWidth, window.innerHeight);
    renderer.shadowMap.enabled = true;
    container.appendChild(renderer.domElement);

    camera = new THREE.PerspectiveCamera(70, window.innerWidth / window.innerHeight, 1, 100);
    camera.position.set(0, -4, -1.5);

    loader = new THREE.TextureLoader();
    loader.setCrossOrigin("");

    scene = new THREE.Scene();
    bgTexture = loader.load("https://raw.githubusercontent.com/Rabbid76/graphics-snippets/master/resource/texture/background.jpg",
        function ( texture ) {
            var img = texture.image;
            bgWidth= img.width;
            bgHeight = img.height;
            resize();
        }
    );
    scene.background = bgTexture;
    bgTexture.wrapS = THREE.MirroredRepeatWrapping;
    bgTexture.wrapT = THREE.MirroredRepeatWrapping;
  
    scene.add(camera);
    window.onresize = resize;
    
    var ambientLight = new THREE.AmbientLight(0x404040);
    scene.add(ambientLight);

    var directionalLight = new THREE.DirectionalLight( 0xffffff, 0.5 );
    directionalLight.position.x = -0.75;
    directionalLight.position.y = -0.5;
    directionalLight.position.z = -1;
    scene.add( directionalLight );

    controls = new THREE.OrbitControls(camera, renderer.domElement);
		
    createModel();
  }

  function createModel() {

    var material = new THREE.MeshPhongMaterial({color:'#b090b0'});
    var geometry = new THREE.BoxGeometry( 1, 1, 1 );
    var mesh = new THREE.Mesh(geometry, material);

    scene.add(mesh);
  }

  function resize() {
    
    var aspect = window.innerWidth / window.innerHeight;
    var texAspect = bgWidth / bgHeight;
    var relAspect = aspect / texAspect;

    bgTexture.repeat = new THREE.Vector2( Math.max(relAspect, 1), Math.max(1/relAspect,1) ); 
    bgTexture.offset = new THREE.Vector2( -Math.max(relAspect-1, 0)/2, -Math.max(1/relAspect-1, 0)/2 ); 

    renderer.setSize(window.innerWidth, window.innerHeight);
    camera.aspect = aspect;
    camera.updateProjectionMatrix();
  }

  function animate() {
    requestAnimationFrame(animate);
    render();
  }

  function render() {
    renderer.render(scene, camera);
  }
})();

<script src="https://threejs.org/build/three.min.js"></script>
<!--script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/89/three.min.js"></script-->
<script src="https://threejs.org/examples/js/controls/OrbitControls.js"></script>

<div id="container"></div>

【讨论】：

使用 scene.background 似乎是添加背景图像的最简单方法。但是，您的代码会呈现扭曲的背景图像（因为它与窗口分辨率匹配）。知道如何解决这个问题吗？

【解决方案5】：

谢谢你））

我找到了另一个解决方案：

<!DOCTYPE html>
<head>
    <title>three.js webgl - orbit controls</title>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
    <style>
        body {
            color: #000;
            font-family:Monospace;
            font-size:13px;
            text-align:center;
            font-weight: bold;
            background-image:url(./foto.jpg);

            margin: 0px;
            overflow: hidden;
        }

        #info {
            color:#000;
            position: absolute;
            top: 0px; width: 100%;
            padding: 5px;

        }

        a {
            color: red;
        }
    </style>
</head>

<body>
    <div id="container"></div>
    <div id="info">

        <a href="http://threejs.org" target="_blank">three.js</a> 
    </div>

    <script src="./three.min.js"></script>
    <script src="js/loaders/OBJLoader.js"></script>
    <script src="js/controls/OrbitControls.js"></script>

    <script src="js/Detector.js"></script>
    <script src="js/libs/stats.min.js"></script>
    <!--используем для вывода информации fps-->

    <script>
        if ( ! Detector.webgl ) Detector.addGetWebGLMessage();
        var container, stats;
        var camera, controls, scene, renderer;
        var cross;

        init();
        animate();

        function init() {       

            camera = new THREE.PerspectiveCamera( 90, window.innerWidth / window.innerHeight, 0.1, 2000 );
            camera.position.z = 100;
            controls = new THREE.OrbitControls( camera );
            controls.addEventListener( 'change', render );
            scene = new THREE.Scene();

            var manager = new THREE.LoadingManager();
            manager.onProgress = function ( item, loaded, total ) {

                console.log( item, loaded, total );

            };

            var texture = new THREE.Texture();
            var loader = new THREE.ImageLoader( manager );
            loader.load( './kos.jpg', function ( image ) {

                texture.image = image;
                texture.needsUpdate = true;

            } );

            // model

            var loader = new THREE.OBJLoader( manager );
            loader.load( './skull.obj', function ( object ) {
                object.traverse( function ( child ) {
                    if ( child instanceof THREE.Mesh ) {
                        child.material.map = texture;
                    }
                } );
                object.position.y = 10;
                scene.add( object );
            } );


            // lights

            light = new THREE.DirectionalLight( 0xffffff );
            light.position.set( 1, 1, 1 );
            scene.add( light );

            light = new THREE.DirectionalLight( 0xffffff  );
            light.position.set( -1, -1, -1 );
            scene.add( light );

            light = new THREE.AmbientLight( 0xffffff );
            scene.add( light );


            renderer = new THREE.WebGLRenderer( { antialias: false } );
             renderer.setSize(window.innerWidth, window.innerHeight);
            document.body.appendChild(renderer.domElement);

            container = document.getElementById( 'container' );
            container.appendChild( renderer.domElement );
            stats = new Stats();
            stats.domElement.style.position = 'absolute';
            stats.domElement.style.top = '0px';
            stats.domElement.style.zIndex = 100;
            container.appendChild( stats.domElement );
            window.addEventListener( 'resize', onWindowResize, false );
        }


        function onWindowResize() {
            camera.aspect = window.innerWidth / window.innerHeight;
            camera.updateProjectionMatrix();
            renderer.setSize( window.innerWidth, window.innerHeight );
            render();

        }

        function animate() {
            requestAnimationFrame( animate );
            controls.update();

        }

        function render() {

            renderer.render( scene, camera );
            stats.update();
        }


    </script>

</body>

【讨论】：

很遗憾，您的代码不适用于three.js r78，您可能在构建webgl渲染时忘记将alpha设置为true，这是查看body背景图像的关键点。
@user2969890 我喜欢您的解决方案 (+1)，因为您只是在使用纹理清除缓冲区。我尝试了相同的方法，但要么我收到关于纹理不是 2 的幂以及缩小或不正确的纵横比的警告。您是如何解决在使用纹理作为场景背景时保持纵横比的问题的？

【解决方案6】：

今天似乎很晚才向这个线程添加任何贡献，但这是我的“hap'orth”：

    <head>
        <meta charset=utf-8>
        <title>Temple7</title>
        <style>
            body { margin: 0;
                 }
            canvas { width: 100%; height: 100%;
                  background-image:url(Clouds.jpg);
                }
        </style>
    </head>

这种相当简单的方法有其局限性。 .jpg 图像保留其像素尺寸，因此对于不同大小的浏览器窗口，人们可以看到不同数量的图像。如果画布大小超过 .jpg 的大小，则会发生平铺。

【讨论】：