I have a map outline which I would like to reveal as if it were being drawn. How can I generate a layer which basically shows what is beneath it only where they overlap?
My initial attempt is to trace the map outline with a fat vector paint brush, animate the vector paint effect so that it "draws" in time. Then assign the vector layer, which is above the map outline layer, to a Stencil Luma blend mode. But I get half the desired effect: the part of the map "yet to be uncovered" is already there, but grey, while the vector paint intersecting layer reveals in full white (the intended color) as it draws around.
This has to be one of the earliest AE demands, but I never learned it...! : assigning a layer to reveal the one below it based on intersecting pixels.