Animate object along a path

Object follows the path defined.

HTML

<script src="http://threejs.org/build/three.min.js"></script>
<script src="http://threejs.org/examples/js/controls/OrbitControls.js"></script>

CSS

body {
	background-color: #000;
	margin: 0px;
	overflow: hidden;
}

JavaScript

// GLOBALS - ALLOCATE THESE OUTSIDE OF THE RENDER LOOP - CHANGED
var cubes = [], marker, spline;
var matrix = new THREE.Matrix4();
var up = new THREE.Vector3( 0, 1, 0 );
var axis = new THREE.Vector3( );
var pt, radians, axis, tangent, path;

// the getPoint starting variable - !important - You get me ;)
var t = 0;

//This function generates the cube and chooses a random color for it 
//on intial load.

function getCube(){
    // cube mats and cube
    var mats = [];
    for (var i = 0; i < 6; i ++) {
        mats.push(new THREE.MeshBasicMaterial({color:Math.random()*0xffffff}));
    }
    
    var cube = new THREE.Mesh(
        new THREE.CubeGeometry(2, 2, 2),
        new THREE.MeshFaceMaterial( mats )
    );
   
    return cube
}

// Ellipse class, which extends the virtual base class Curve
function Ellipse( xRadius, yRadius ) {

		THREE.Curve.call( this );

		// add radius as a property
		this.xRadius = xRadius;
		this.yRadius = yRadius;

}

Ellipse.prototype = Object.create( THREE.Curve.prototype );
Ellipse.prototype.constructor = Ellipse;

// define the getPoint function for the subClass
Ellipse.prototype.getPoint = function ( t ) {

	var radians = 2 * Math.PI * t;

	return new THREE.Vector3( this.xRadius * Math.cos( radians ),
							  this.yRadius * Math.sin( radians ),
							  0 );

};

//

var mesh, renderer, scene, camera, controls;


function init() {

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

    // scene
    scene = new THREE.Scene();
    
    // camera
    camera = new THREE.PerspectiveCamera( 45, window.innerWidth / window.innerHeight, 1, 1000 );
    camera.position.set( 20, 20, 20 );

    // controls
    controls = new THREE.OrbitControls( camera, renderer.domElement );
    controls.addEventListener( 'change', render ); // use if there is no animation loop
    controls.minDistance = 10;
    controls.maxDistance =...