sun lens in game

How do you make a sun lens go behine object in a game. like the sun light in the new game Battlefield 3?:spin:

Did you mean a lens flare effect?
http://translate.google.com/translate?js=n&prev=_t&hl=de&ie=UTF-8&layout=2&eotf=1&sl=de&tl=en&u=http%3A%2F%2Fwww.blendpolis.de%2Ff%2Farticle_view.php%3Ffaq%3D6%26fldAuto%3D8

Thanks this looked like it will help.:stuck_out_tongue: