Hi, thanks for response, but I barely understand you. How do you imagine this: [emptyTile]+1 this will return just another tile e.g. my empty tile is 1, so 1+1=2 (2 is non-existent tile).
UPD: Your idea will work if modified, however it makes a square but not a circle as I'm trying to implement.:
https://i.postimg.cc/8cg6X7KL/tilemap-fow.png[/img]