Reveal material with vertex control

Hi, I want to create a material and honestly dont know where to even get started.

-The material should be invisible at start

-Whenever I press the E key, any asset inside players “effect range” (e.g. radius 10) should begin to reveal texture, but only the area that is collapsing with the players “effect range”. If an asset is too large, a part of it would be “revealed”, but player would need to keep moving its “magic range” area so the whole asset gets revealed.

That would be the first thing I would like to know how to do.

Thanks in advance!

anyone? is it too hard ?