three.js/examples/js/loaders/MDDLoader.js

( function () {

	/**
 * MDD is a special format that stores a position for every vertex in a model for every frame in an animation.
 * Similar to BVH, it can be used to transfer animation data between different 3D applications or engines.
 *
 * MDD stores its data in binary format (big endian) in the following way:
 *
 * number of frames (a single uint32)
 * number of vertices (a single uint32)
 * time values for each frame (sequence of float32)
 * vertex data for each frame (sequence of float32)
 */

	var MDDLoader = function ( manager ) {

		THREE.Loader.call( this, manager );

	};

	MDDLoader.prototype = Object.assign( Object.create( THREE.Loader.prototype ), {
		constructor: MDDLoader,
		load: function ( url, onLoad, onProgress, onError ) {

			var scope = this;
			var loader = new THREE.FileLoader( this.manager );
			loader.setPath( this.path );
			loader.setResponseType( 'arraybuffer' );
			loader.load( url, function ( data ) {

				onLoad( scope.parse( data ) );

			}, onProgress, onError );

		},
		parse: function ( data ) {

			var view = new DataView( data );
			var totalFrames = view.getUint32( 0 );
			var totalPoints = view.getUint32( 4 );
			var offset = 8; // animation clip

			var times = new Float32Array( totalFrames );
			var values = new Float32Array( totalFrames * totalFrames ).fill( 0 );

			for ( var i = 0; i < totalFrames; i ++ ) {

				times[ i ] = view.getFloat32( offset );
				offset += 4;
				values[ totalFrames * i + i ] = 1;

			}

			var track = new THREE.NumberKeyframeTrack( '.morphTargetInfluences', times, values );
			var clip = new THREE.AnimationClip( 'default', times[ times.length - 1 ], [ track ] ); // morph targets

			var morphTargets = [];

			for ( var i = 0; i < totalFrames; i ++ ) {

				var morphTarget = new Float32Array( totalPoints * 3 );

				for ( var j = 0; j < totalPoints; j ++ ) {

					var stride = j * 3;
					morphTarget[ stride + 0 ] = view.getFloat32( offset );
					offset += 4; // x

					morphTarget[ stride + 1 ] = view.getFloat32( offset );
					offset += 4; // y

					morphTarget[ stride + 2 ] = view.getFloat32( offset );
					offset += 4; // z

				}

				var attribute = new THREE.BufferAttribute( morphTarget, 3 );
				attribute.name = 'morph_' + i;
				morphTargets.push( attribute );

			}

			return {
				morphTargets: morphTargets,
				clip: clip
			};

		}
	} );

	THREE.MDDLoader = MDDLoader;

} )();