I found an article that present an algorithm that claimed to be the fastest way to make a real time soft shadow and it calls :
" Forward Shadow Mapping " .
The link is http://www.cs.unc.edu/~zhangh/shadow.html
In that page there is a link to a ps document. I download it, but it’s contains only the abstract and introduction.
Maybe someone know this algorithm or any link to the full artical ???