static void RemoveCaster(ShadowCaster c)
 {
     casters.Remove(c);
     for (int i = 0; i < casters.Count; i++)
     {
         casters[i].index = 1 << i;
         casters[i].ApplyPropertyBlock();
     }
 }
 static int AddCaster(ShadowCaster c)
 {
     casters.Add(c);
     return(casters.Count - 1);
 }