__I am not a smart man* (*when it comes to AE)... need help with Masks - specifically making a mask

[Hugh Betcha]

I want to make a mask from a vector object (let's say a hexagon).

I have footage of a store, which I want to mask with this object for only part of the duration (not a track matte, since it seems like I can't make it appear/disappear etc.)

How on earth do I do this?

 

I know a lot of you will say "This is basic, dumbass!" - to them I say, yes, I am a dumbass when it comes to AE which is super complex, and I'm 100% self taught.

[OussK]

you know 50% of the solution :), use alpha mate and set a opacity keyframes for the hexagon shape, and to sure the keyframe will shift from 100 to zero without any fade effect try to use toggle hold keyframe .

 

[Hugh Betcha]

Thanks OussK!