Update docs for AnimationMixer and GLTFLoader.

docs/api/animation/AnimationMixer.html

@@ -11,9 +11,61 @@
 		<h1>[name]</h1>
 
 		<div class="desc">
-    The AnimationMixer is a player for AnimationClip objects.
+		The AnimationMixer is a player for animations on a particular object in the scene.
 		</div>
 
+		<p>
+		Each available animation sequence is stored as an [page:AnimationClip AnimationClip], and
+		playback of that clip is controlled with an [page:AnimationClip AnimationAction]. When multiple
+		objects in the scene are animated independently, one AnimationMixer may be used for each object.
+		</p>
+
+		<h2>Example</h2>
+
+		<p>
+		When loading a 3D model that includes animation, many loaders also return a list of
+		[page:AnimationClip AnimationClip] instances. Each clip represents a specific animation
+		sequence, and may be played or paused individually.
+		</p>
+
+		<code>
+		var mesh;
+
+		// Create an AnimationMixer, and get the list of AnimationClip instances
+		var mixer = new THREE.AnimationMixer( mesh );
+		var clips = mesh.animations;
+
+		// Update the mixer on each frame
+		function update () {
+			mixer.update( deltaSeconds );
+		}
+
+		// Play a specific animation
+		var clip = THREE.AnimationClip.findByName( clips, 'dance' );
+		var action = mixer.clipAction(clip);
+		action.play();
+
+		// Play all animations
+		clips.forEach( function (clip) {
+			mixer.clipAction(clip).play();
+		} );
+		</code>
+
+		<p>
+		Note that not all model formats include animation (OBJ notably does not), and that only some
+		THREE.js loaders support [page:AnimationClip AnimationClip] sequences. Several that <i>do</i>
+		support this animation type:
+		</p>
+
+		<ul>
+			<li>[page:ObjectLoader THREE.ObjectLoader]</li>
+			<li>THREE.BVHLoader</li>
+			<li>THREE.FBXLoader</li>
+			<li>THREE.FBXLoader2</li>
+			<li>[page:GLTFLoader THREE.GLTFLoader]</li>
+			<li>THREE.MMDLoader</li>
+			<li>THREE.SEA3DLoader</li>
+		</ul>
 
 		<h2>Constructor</h2>
 

docs/examples/loaders/GLTFLoader.html

@@ -26,18 +26,18 @@
 		<h2>Example</h2>
 
 		<code>
-		// instantiate a loader
+		// Instantiate a loader
 		var loader = new THREE.GLTFLoader();
 
-		// load a glTF resource
-		loader.load(
-			// resource URL
-			'models/gltf/duck/duck.json',
-			// Function when resource is loaded
-			function ( object ) {
-				scene.add( object.scene );
-			}
-		);
+		// Load a glTF resource
+		loader.load( 'models/gltf/duck/duck.gltf', function ( gltf ) {
+			scene.add( gltf.scene );
+
+			gltf.animations; // Array&lt;THREE.AnimationClip&gt;
+			gltf.scene;      // THREE.Scene
+			gltf.scenes;     // Array&lt;THREE.Scene&gt;
+			gltf.cameras;    // Array&lt;THREE.Camera&gt;
+		} );
 		</code>
 
 		[example:webgl_loader_gltf]