Larian Studios Forums Divinity - Original Sin Divinity Original Sin - Mods What button he press to create the Atmosphere??

In this video he is making atmosphere triggers

http://www.youtube.com/watch?feature=player_detailpage&v=QGcN2A7E2Jo#t=137

He says "Oops i have to press the button" at that time.. but all he clicks is Toggle visibility button. I think i heard the keyboard press a button. Did he press another button??