Three.js 2 image canvas as texture map

combining 2 images on a canvas for use as material texture. In responce to: http://stackoverflow.com/questions/14742381

HTML

<script src="https://rawgit.com/mrdoob/three.js/master/build/three.min.js"></script>
<script src="https://rawgit.com/mrdoob/stats.js/master/src/Stats.js"></script>

CSS

body {
    padding: 0;
    margin: 0;
}

JavaScript

var camera, scene, renderer, mesh, material;
init();
animate();


function getCanvasImage() {
	  
  var canvas = document.createElement('canvas');
  canvas.width  = 512;
	canvas.height = 512;
	var context = canvas.getContext('2d');
	var texture = new THREE.Texture(canvas) ;
  
  var imageObj = new Image();
	imageObj.src = patternData();
	imageObj.onload = function()
	{  
		context.drawImage(imageObj, 0, 0);
		texture.needsUpdate = true;
    var imgObj2 = new Image();
    imgObj2.src = imageData1();
    imgObj2.onload = function(){
    	context.drawImage(imgObj2, 0, 0);
      texture.needsUpdate = true;
    }
	};
  
  return texture;
  
}

function init() {
    // Renderer.
    renderer = new THREE.WebGLRenderer();
    //renderer.setPixelRatio(window.devicePixelRatio);
    renderer.setSize(window.innerWidth, window.innerHeight);
    // Add renderer to page
    document.body.appendChild(renderer.domElement);

    // Create camera.
    camera = new THREE.PerspectiveCamera(70, window.innerWidth / window.innerHeight, 1, 1000);
    camera.position.z = 400;

    // Create scene.
    scene = new THREE.Scene();

    // Create material
    material = new THREE.MeshBasicMaterial({map:getCanvasImage()});

    // Create cube and add to scene.
    var geometry = new THREE.BoxGeometry(200, 200, 200);
    mesh = new THREE.Mesh(geometry, material);
    scene.add(mesh);

    // Create ambient light and add to scene.
    var light = new THREE.AmbientLight(0x404040); // soft white light
    scene.add(light);

    // Create directional light and add to scene.
    var directionalLight = new THREE.DirectionalLight(0xffffff);
    directionalLight.position.set(1, 1, 1).normalize();
    scene.add(directionalLight);

    // Add listener for window resize.
    window.addEventListener('resize', onWindowResize, false);

    // Add stats to page.
    stats = new Stats();
    stats.domElement.style.position = 'absolute';
    stats.domElement.style.bottom = '0px';
   ...