It should seperate the foreground from the background (like in the pictures). I was thinking maybe a shader, or representing the outline itself via objects. Anyone have a straightforward approach?
I have the same issue but found no answer yet!
One way would be to add a shadow texture to every solid tile prefab like this:
This should render between the solid and background tiles and looks like this:
But you can ofcourse play with the gradient and resolution of the shadow texture to get the result you want. Using a shader is probably a better idea, but this is what I came up with!