Moving decals realtime.

So i am working on a prototype system to make some simple and fast spell effects.
I will eventually port over to AFX 2.0 but for the time being i decided to go with my own system.

However, i came across some trouble when i wanted to have a decal on the ground. I wanted it to be an AoE indicator (like when casting blizzard in WoW or other range AoE's)
I found a working solution doing this:

function spawnIndicatorDecal()
{
   if($SpellDecal $= "")
   {
      %player = $Pref::PlayerID;
      %pos = castrayfromNPC(%player, "point");
      %norm = castrayfromNPC(%player, "normal");
      $SpellDecal = decalManagerAddDecal( %pos, %norm, 0, 1, "NewDecalData", true );
      schedule(20, 0, updateSpellDecal);
   }
}

function updateSpellDecal()
{
   if($SpellDecal !$= "")
   {
      %player = $Pref::PlayerID;
      decalManagerRemoveDecal( $SpellDecal );
      %pos = castrayfromNPC(%player, "point");
      %norm = castrayfromNPC(%player, "normal");
      $SpellDecal = decalManagerAddDecal( %pos, %norm, 0, 1, "NewDecalData", true );
      schedule(20, 0, updateSpellDecal);
   }
}

(Yes my naming is kindda awkward, will clean it sometime)
But it gives alot of flickr, and i believe Raycasts only runs over the server (not sure about this) if so it would create a lot of traffic between the client and the server.

So wanted to know if there was anyone who had figured a better way to do this :)
This code is fine for prototyping, but i were considering to clean up the code and release it as a resource for beginners like me who haven't got their hands in to the source code yet.
But i believe that AoE indicator is too ineffective.