title: Can a plane cast shadow on another plane in Three.js?
body: <p>I have a plane with a transparent PNG (a world map).<br>
  <strong>Can I cast shadows from one plane onto another plane?</strong>  </p>
  
  <p>I am having no success with this code:</p>
  
  <pre><code>plane = new THREE.Mesh(new THREE.PlaneGeometry(200,200), new THREE.MeshLambertMaterial({color: 0xcccccc}));
  
  var mapTexture = new THREE.ImageUtils.loadTexture("img/map_transp2.png");
      mapTexture.needsUpdate = true;
      var mapMaterial = new THREE.MeshBasicMaterial({
          color:0xaaaaaa,
          transparent:true,
          map:mapTexture,
          side:THREE.DoubleSide
      });
  
  mapPlane = new THREE.Mesh(new THREE.PlaneGeometry(800/5,370/5), mapMaterial);
  
  plane.receiveShadow = true;
  mapPlane.castShadow = true;
  </code></pre>