1 <layers>

     2 <visual>

     3 <param name="opacity" type="anim">

     4 <duration>2.0</duration>

     5 <style>linear</style>

     6 <keyframe at="0.0">1.0</keyframe>

     7 <keyframe at="0.5">0.25</keyframe>

     8 <keyframe at="1.0">0</keyframe>

     9 </param>

    10 

    11 </visual>

    12 </layers>

    13