this.scale = function(scaleFactor)
      {
        var i; 
        
        for(i = 0; i < this.joints.length; i++)
        {
          this.joints[i].scale(scaleFactor); 
        }
        for(i = 0; i < this.sticks.length; i++)
        {
          this.sticks[i].scale(scaleFactor); 
        }
        this.radius *= scaleFactor; 
      }