No, you have seen maps that give the illusion of no fog/ visible distance...
For your dictionary:
Visible distance: The physical distance you can see or detect objects, if it is out of this range, your computer ignores it...
Fog:The radding of objects given to make the Visible Distance less like a line and more like a natural occurring thing.
Having no fog is possible, but it just makes the visible distance stand out and look unpolished. Having no limit to visible distance is impossible because it goes on forever, and therefor, your computer would take and infinite amount of time to render a single frame, what really happens is BL just crashes from an overload.
edit:Woops, sry for the bump, didn't check the topic date XD