/**
  * Plays an animation once.
  *
  * @param duration_seconds - length of time to play the animation in seconds
  * @param ident - Images are loaded as name+ident (Tavish + _Walk_North)
  */
 public void animate(double duration_seconds, String ident) {
   fireEvent(name + ident, false, true);
   isLooping = false;
   isTicking = true;
   if (currImgName.equalsIgnoreCase(name + ident)) {
     return;
   }
   seriesPosition = 0;
   totalAnimTime_Millis = 0;
   sequenceDuration_Millis = duration_seconds * 1000;
   seriesLength = ImageLoader.getSeriesCount(name + ident);
   cycleLength_Millis = sequenceDuration_Millis / seriesLength;
   currImgName = name + ident;
 }