70
votes

I am starting with THREE.js, and I am trying to draw a rectangle with a texture on it, lit by a single source of light. I think this is as simple as it gets (HTML omitted for brevity):

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);
}

The problem is, I cannot see anything. If I change the material and use the commented one, a square appears as I would expect. Note that

  • The texture is 256x256, so its sides are power of two
  • The function is actually called when the body is loaded; indeed it works with a different material.
  • It does not work even if I serve the file from a webserver, so it is not an issue of cross-domain policy not allowing to load the image.

What I am I doing wrong?

6

6 Answers

73
votes

By the time the image is loaded, the renderer has already drawn the scene, hence it is too late. The solution is to change

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

into

texture = THREE.ImageUtils.loadTexture('crate.gif', {}, function() {
    renderer.render(scene);
}),
27
votes

Andrea solution is absolutely right, I will just write another implementation based on the same idea. If you took a look at the THREE.ImageUtils.loadTexture() source you will find it uses the javascript Image object. The $(window).load event is fired after all Images are loaded ! so at that event we can render our scene with the textures already loaded...

  • 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
    
  • 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);
        });
    });
    

Thanks...

23
votes

In version r75 of three.js, you should use:

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);
});
6
votes

In version r82 of Three.js TextureLoader is the object to use for loading a texture.

Loading one texture (source code, demo)

Extract (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);

Loading multiple textures (source code, demo)

In this example the textures are loaded inside the constructor of the mesh, multiple texture are loaded using Promises.

Extract (Globe.js):

Create a new container using Object3D for having two meshes in the same container:

var Globe = function (radius, segments) {

  THREE.Object3D.call(this);

  this.name = "Globe";

  var that = this;

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

A map called textures where every object contains the url of a texture file and val for storing the value of a Three.js texture object.

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

The array of promises, for each object in the map called textures push a new Promise in the array texturePromises, every Promise will call loader.load. If the value of entry.val is a valid THREE.Texture object, then resolve the promise.

  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 takes the promise array texturePromises as argument. Doing so makes the browser wait for all the promises to resolve, when they do we can load the geometry and the material.

  // 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);
  });

For the cloud sphere only one texture is necessary:

  // 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;
1
votes

Without Error Handeling

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

With Error Handling

// 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);

Result:

enter image description here

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

0
votes

Use TextureLoader to load a image as texture and then simply apply that texture to scene background.

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

Result:

https://codepen.io/hiteshsahu/pen/jpGLpq?editors=0011

Flat Earth Three.JS@hiteshsahuCodePen