xin="spin" animation__spin="property: object3D.rotation.x"></a-mixin>

        <a-mixin id="color" material="color: #FFFFC3"></a-mixin>
        <a-mixin id="doubleside" material="side: double"></a-mixin>

        <img id="carpet" src="carpet.jpg">
        <img id="floor" src="marble.jpg">
      </a-assets>

      <a-camera position="0 1.6 4"></a-camera>

      <!-- Lights. -->
      <a-entity light="type: ambient; color: #444"></a-entity>
      <a-entity light="type: directional; color: #EEE" position="0 1 