Line of sight to solid objects.

I know I'm probably handling this in an inefficient way but, to make a map discover-able I am using dark sprites that are destroyed when in line of sight.

The problem is that if the dark sprite is above a wall it does not reveal the wall.

I tried having an event like

if wall is in line of sight and overlapping darksprite then destroy darksprite.

But that didn't work either. So a solid wall blocks itself form being in line of sight.

Any recommendations on how to proceed. Everything I find online seams out of date or based on construct classic. If I could just remove the darksprite above a wall in line of sight i'd be set.

It seams that having a map reveal or fog of war that is limited by walls is difficult for many people in construct 2. I may have to make a temporary work around by revealing walls that you are one tile away from even though line of site would go much further into the room or down a hall.