I am stuck here, for some reason I think this is not going to happen. Although I do not know why? CS6 ??
I want a mask to cover my actor until revealed via a mask path. But here is the 'kicker' I want to do it on a transparent background. Where ( I think) I want my mask to Subtract (subtract to nothing or transparent BG) until path is KF'd.
A pic is worth a 1000
Precomp the chroma key shot and mask away.
Thanks Dave how I did I forget the most powerful tool in the drawer....