在THREE.js中使用纹理

70

我从THREE.js开始，我试图绘制一个带有纹理的矩形，并用单个光源照明。我认为这很简单（为简洁起见，省略了HTML）：

function loadScene() {
    var world = document.getElementById('world'),
        WIDTH = 1200,
        HEIGHT = 500,
        VIEW_ANGLE = 45,
        ASPECT = WIDTH / HEIGHT,
        NEAR = 0.1,
        FAR = 10000,

        renderer = new THREE.WebGLRenderer(),
        camera = new THREE.Camera(VIEW_ANGLE, ASPECT, NEAR, FAR),
        scene = new THREE.Scene(),
        texture = THREE.ImageUtils.loadTexture('crate.gif'),
        material = new THREE.MeshBasicMaterial({map: texture}),
        // material = new THREE.MeshPhongMaterial({color: 0xCC0000});
        geometry = new THREE.PlaneGeometry(100, 100),
        mesh = new THREE.Mesh(geometry, material),
        pointLight = new THREE.PointLight(0xFFFFFF);

    camera.position.z = 200;    
    renderer.setSize(WIDTH, HEIGHT);
    scene.addChild(mesh);
    world.appendChild(renderer.domElement);
    pointLight.position.x = 50;
    pointLight.position.y = 50;
    pointLight.position.z = 130;
    scene.addLight(pointLight); 
    renderer.render(scene, camera);
}

问题是，我什么都看不到。如果我更改材料并使用带注释的材料，则会出现一个正方形。注意

  • 纹理为256x256，因此其侧面为2的幂
  • 该函数实际上是在加载主体时调用的；确实，它适用于其他材料。
  • 即使我从Web服务器提供文件，它也不起作用，因此这不是不允许加载图像的跨域策略的问题。

我做错了什么？

javascript  three.js 
— 安德里亚
source

Answers:

73

到加载图像时，渲染器已经绘制了场景，因此为时已晚。解决方案是改变

texture = THREE.ImageUtils.loadTexture('crate.gif'),

进入

texture = THREE.ImageUtils.loadTexture('crate.gif', {}, function() {
    renderer.render(scene);
}),
— 安德里亚
source
9
如今，答案是抛弃THREE.ImageUtils.loadTexture（已弃用）并THREE.TextureLoader.load改为使用。ImageUtils根本不适合我，但TextureLoader第一次尝试时效果很好。文件：Threejs.org/docs/index.html#api/loaders/TextureLoader
— ArtOfWarfare
27

Andrea解决方案绝对正确，我将基于相同的想法编写另一个实现。如果您查看THREE.ImageUtils.loadTexture（）源，您会发现它使用了JavaScript Image对象。加载所有图像后，将触发$（window）.load事件！因此在那种情况下，我们可以使用已经加载的纹理渲染场景...

  • CoffeeScript

    $(document).ready ->

    material = new THREE.MeshLambertMaterial(map: THREE.ImageUtils.loadTexture("crate.gif"))

    sphere   = new THREE.Mesh(new THREE.SphereGeometry(radius, segments, rings), material)

    $(window).load ->
        renderer.render scene, camera

  • 的JavaScript

    $(document).ready(function() {

    material = new THREE.MeshLambertMaterial({ map: THREE.ImageUtils.loadTexture("crate.gif") });

    sphere = new THREE.Mesh(new THREE.SphereGeometry(radius, segments, rings), material);

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

谢谢...

— 穆斯塔法
source
22

在three.js的r75版本中，应使用：

var loader = new THREE.TextureLoader();
loader.load('texture.png', function ( texture ) {
  var geometry = new THREE.SphereGeometry(1000, 20, 20);
  var material = new THREE.MeshBasicMaterial({map: texture, overdraw: 0.5});
  var mesh = new THREE.Mesh(geometry, material);
  scene.add(mesh);
});
— 叶业
source
好答案！我猜测自原始答案以来，API发生了变化。您的答案是实用的！非常感谢！
— CowWarrior
您可能应该提供了您引用的Three.js的最新修订版。
— 严苛的
6

在three.js所版本R82 TextureLoader是用来加载纹理的对象。

加载一个纹理（源代码，演示）

提取（test.js）：

var scene = new THREE.Scene();
var ratio = window.innerWidth / window.innerHeight;
var camera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight,
  0.1, 50);

var renderer = ...

[...]

/**
 * Will be called when load completes.
 * The argument will be the loaded texture.
 */
var onLoad = function (texture) {
  var objGeometry = new THREE.BoxGeometry(20, 20, 20);
  var objMaterial = new THREE.MeshPhongMaterial({
    map: texture,
    shading: THREE.FlatShading
  });

  var mesh = new THREE.Mesh(objGeometry, objMaterial);

  scene.add(mesh);

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

    mesh.rotation.x += 0.010;
    mesh.rotation.y += 0.010;

    renderer.render(scene, camera);
  };

  render();
}

// Function called when download progresses
var onProgress = function (xhr) {
  console.log((xhr.loaded / xhr.total * 100) + '% loaded');
};

// Function called when download errors
var onError = function (xhr) {
  console.log('An error happened');
};

var loader = new THREE.TextureLoader();
loader.load('texture.jpg', onLoad, onProgress, onError);

加载多个纹理（源代码，演示）

在此示例中，纹理被加载到网格的构造函数中，使用Promises来加载多个纹理。

提取（Globe.js）：

创建一个新容器，Object3D用于在同一容器中具有两个网格：

var Globe = function (radius, segments) {

  THREE.Object3D.call(this);

  this.name = "Globe";

  var that = this;

  // instantiate a loader
  var loader = new THREE.TextureLoader();

称为的映射textures，其中每个对象都包含url纹理文件的，val用于存储Three.js纹理对象的值。

  // earth textures
  var textures = {
    'map': {
      url: 'relief.jpg',
      val: undefined
    },
    'bumpMap': {
      url: 'elev_bump_4k.jpg',
      val: undefined
    },
    'specularMap': {
      url: 'wateretopo.png',
      val: undefined
    }
  };

承诺数组，对于映射中的每个对象，将其textures推入数组中的新Promise时texturePromises，每个Promise都会调用loader.load。如果的值entry.val是有效的THREE.Texture对象，则解决承诺。

  var texturePromises = [], path = './';

  for (var key in textures) {
    texturePromises.push(new Promise((resolve, reject) => {
      var entry = textures[key]
      var url = path + entry.url

      loader.load(url,
        texture => {
          entry.val = texture;
          if (entry.val instanceof THREE.Texture) resolve(entry);
        },
        xhr => {
          console.log(url + ' ' + (xhr.loaded / xhr.total * 100) +
            '% loaded');
        },
        xhr => {
          reject(new Error(xhr +
            'An error occurred loading while loading: ' +
            entry.url));
        }
      );
    }));
  }

Promise.all将promise数组texturePromises作为参数。这样做会使浏览器等待所有的承诺解决，当它们完成后，我们就可以加载几何图形和材质。

  // load the geometry and the textures
  Promise.all(texturePromises).then(loadedTextures => {

    var geometry = new THREE.SphereGeometry(radius, segments, segments);
    var material = new THREE.MeshPhongMaterial({
      map: textures.map.val,
      bumpMap: textures.bumpMap.val,
      bumpScale: 0.005,
      specularMap: textures.specularMap.val,
      specular: new THREE.Color('grey')
    });

    var earth = that.earth = new THREE.Mesh(geometry, material);
    that.add(earth);
  });

对于云球，仅需要一种纹理：

  // clouds
  loader.load('n_amer_clouds.png', map => {
    var geometry = new THREE.SphereGeometry(radius + .05, segments, segments);
    var material = new THREE.MeshPhongMaterial({
      map: map,
      transparent: true
    });

    var clouds = that.clouds = new THREE.Mesh(geometry, material);
    that.add(clouds);
  });
}

Globe.prototype = Object.create(THREE.Object3D.prototype);
Globe.prototype.constructor = Globe;
— 马克
source
1

没有错误处理

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

具有错误处理

// Function called when download progresses
var onProgress = function (xhr) {
  console.log((xhr.loaded / xhr.total * 100) + '% loaded');
};

// Function called when download errors
var onError = function (error) {
  console.log('An error happened'+error);
};

//Function  called when load completes.
var onLoad = function (texture) {
  var objGeometry = new THREE.BoxGeometry(30, 30, 30);
  var objMaterial = new THREE.MeshPhongMaterial({
    map: texture,
    shading: THREE.FlatShading
  });

  var boxMesh = new THREE.Mesh(objGeometry, objMaterial);
  scene.add(boxMesh);

  var render = function () {
    requestAnimationFrame(render);
    boxMesh.rotation.x += 0.010;
    boxMesh.rotation.y += 0.010;
      sphereMesh.rotation.y += 0.1;
    renderer.render(scene, camera);
  };

  render();
}


//LOAD TEXTURE and on completion apply it on box
var loader = new THREE.TextureLoader();
    loader.load('https://upload.wikimedia.org/wikipedia/commons/thumb/9/97/The_Earth_seen_from_Apollo_17.jpg/1920px-The_Earth_seen_from_Apollo_17.jpg', 
                onLoad, 
                onProgress, 
                onError);

结果：

在此处输入图片说明

https://codepen.io/hiteshsahu/pen/jpGLpq/

— Hitesh Sahu
source
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