Great Work: Photon Mapping to Pixel Shader: we also strugle with that:

I'd rather love to reffer:
[1]
[2]

Our ways:

DirectX Pixel Shapder(Microsoft):

Very thanks to GNU:

Something, we'd rather love to have interesting:
https://www.facebook.com/photo.php?fbid=3792651297442414&set=gm.2875918789122255&type=3&theater