I remember reading about this thing a guy added to cycles that reduced the amount of noise (and the amount of samples needed) through windows, glass, and holes. The object was like a transparent plane you placed over the window or hole, and it did the rest for itself. Is this implemented into cycles yet, and how do i use it? and if not, where can i find this again?
Thank you, that was exactly what i was looking for 
No more 5000-sample renderings for my room 