<layers>
	<visual>
	    <param name="rotation_angle" type="anim">
	        <duration>0.5</duration>
		    <keyframe at="0.0">90</keyframe>	
	            <keyframe at="1.0">180</keyframe>
	     </param>
   	    
	    <param name="rotation_origin_x" ref="visual.width">0.5</param>
	    <param name="rotation_origin_y" ref="visual.height">0.5</param>
	    <param name="rotation_axis_z">1</param>
    	    
	</visual>
</layers>