title: how to interact with obj or collada-model in AFrame
body: <pre><code>&lt;a-assets&gt;
          &lt;a-mixin id="ring" geometry="primitive: ring; radiusOuter: 0.20;
                  radiusInner: 0.15;"
                  material="color: cyan; shader: flat"
                  cursor=" fuse: true"&gt;&lt;/a-mixin&gt;
          &lt;a-asset-item id="mancloth" src="../models/man.obj"&gt;&lt;/a-asset-item&gt;
          &lt;a-asset-item id="manclothmtl" src="../models/man.mtl"&gt;&lt;/a-asset-item&gt;
  &lt;/a-assets&gt;
  &lt;a-entity camera look-controls wasd-controls&gt;&lt;a-entity mixin="ring" position="0 0 -3"&gt;
          &lt;a-animation begin="cursor-click" easing="ease-in" attribute="scale"
                 fill="backwards" from="0.3 0.3 0.3" to="1 1 1"&gt;&lt;/a-animation&gt;
          &lt;a-animation begin="cursor-fusing" easing="ease-in" attribute="scale"
                 fill="forwards" from="1 1 1" to="0.3 0.3 0.3"&gt;&lt;/a-animation&gt;
        &lt;/a-entity&gt;
  &lt;/a-entity&gt;
  &lt;a-obj-model  scale="1 1 1" src="#mancloth" mtl="#manclothmtl"&gt;&lt;/a-obj-model&gt;
  </code></pre>
  
  <p>I use the camera to interact with the obj but aframe.js shows an error on line 57766. How can I solve this problem without changing aframe.js.</p>
  
  <pre><code>var intersectedEl = intersection.object.el;
  intersectedEl.emit('raycaster-intersected', {el: el,intersection:intersection});
  </code></pre>
  
  <p><code>intersection.object</code> is a THREE.Mesh, so intersection.object.el is undefined!</p>