Currently there's no way to make not full-tile walls, because if you stand on the opaque tile you will see everyting around it

Let me show an example:

Gray tiles are the tiles player can't see, white tiles are the tiles player can see, orange lines are opaque walls, red circle is player.
When the player stands on a tile adjacent to the tile with wall it looks okay:
https://imgur.com/a/BWR1DCR

But if the player moves to the tile with opaque wall, this happens:
https://imgur.com/a/KM6Y9j8

As you see now the player can see everything around him, ignoring the opacity, because he stands on the opaque atom.
What I suggest is to add an additional way to calculate the opacity for such objects: the player, when he stands on the opaque tile, should not see the atoms that lays in the direction the object faces, so it would look like on the pictures:
https://imgur.com/a/fY3rzcI