Api to hide isometric walls until a token leaves it area

Exactly what it sounds like I want to make it so that if I have an isometric wall on the token layer have an API automatically either move the token out of the way until the token is no longer in its image area or exchange the token for another version of it that I have on a table that is transparent or make it transparent automatically

This would be possible, but it would be a bit tedious to configure. You'd need to have each wall set up as a rollable table token with one face solid and one transparent, both would need to be in a user library, not the marketplace. You'd then need to associate it with some sort of zone that causes it to switch faces. Likely, you'd draw a poly line that defines the zone, select both, then link them. The script would then store the zone (I'd store it relative to the image and associated with it so you could easily scale and duplicate), and remove the poly line. Probably, you'd want to only do the change for PC tokens, not NPC. Also, you couldn't change the display for only the player whose token is in the zone, it would be for all players.  It would be a moderate amount of work for what seems like limited utility. 

i am fine working on that i already had to do a bunch of stuff anyways putting everything on rollable tables and doing the polyline is completely fine to me because this thing is not a one use thing I is my players main base so I would love for it to work great but if it is to much work for any one to help me at least now what apis would I need to combine or actually making something that works Edit: Is there a way to use collision detection to send a command to token mod so it can do what I wanted?