Painting 2D Walls

Godot Version

Version 4.3

Question

I don’t know how to go about doing this, but what I’m looking for in the end would essentially be dynamic tiles.

Let’s say in this simplified example I want to get the edges of the tiles that fall within a given area.
2dpainting

I would want to then take those edges and paint them as if lighting the area with raycasting, except permanent. This would not run every frame so I’m not worried about performance as much, but the lighting/paint would persist. It would be nice to have a gradient effect on the far edges, but if this is a shader solution (I haven’t properly used shaders yet) then I know that would come naturally.