How do I make the position of a sprite off-center?
<p>I am moving a 2D fireball animation along a path.  The fireball's animation comes from a sprite sheet similar to <a href="http://image.shutterstock.com/z/stock-vector-storyboard-of-fireball-206758396.jpg" rel="nofollow">this</a>.  I want the fireball's position to be treated as the center of the head-part of the fireball, instead of being the center of the entire fireball.  How do I go about accomplishing this?  From what I've seen, it seems like I should be using pivots when I slice my sprite sheet, but I can't find a good tutorial on what pivots are and how to use them.</p>