Wow, There was an answer posted on your last question about this, but it seems to have gone.
As far as I remember it was on the lines of
"You use a quad, and you position it so that it appears one pixel big"
but it might have been
"You make a billboard with a texture the same size as the screen, then you put the billboard so it takes up the screen, then you edit the texture"
Either way the anwer was No... well you can but its a pain in the behind
As far as I remember it was on the lines of
"You use a quad, and you position it so that it appears one pixel big"
but it might have been
"You make a billboard with a texture the same size as the screen, then you put the billboard so it takes up the screen, then you edit the texture"
Either way the anwer was No... well you can but its a pain in the behind