Hi. I'm not sure exactly what this is called and I haven't been able to find through searching so I'm just going to ask.
What I want to do is have a base polygon collider that I can subtract shapes from, through gameplay. So the polygon collider gets "hit", then a shape is subtracted from the hit area. Is there a way to do this? Is there different terminology I should be using?

I've been experimenting with how it might work using tile maps, but that is proving to be too stiff requiring a crazy amount of different tiles.
If you can point me in the right direction that would be amazing. Thanks!