NPCSCAN.OVERLAY IS BEING REWRITTEN
The old codebase was showing its age, so I'd been wanting to do this for awhile. With WoW 8.0, however, Blizzard forced my hand by completely replacing the map subsystem and API.
To reiterate:NPCScan.Overlay is not dead; it's being worked on.
NPCScan.Overlay is an addition to _NPCScan that adds map overlays for rare mob patrols. When you search for a rare in _NPCScan, _NPCScan.Overlay will show where it patrols until you find it.
Note: _NPCScan.Overlay can integrate with NPCScan if you have installed it, but make sure to keep both up to date if you do use both!
If you have a question check the FAQ, or a problem create a ticket
Details
World Map
In addition to drawing paths on the World Map, _NPCScan.Overlay adds a key to a corner of the window with each rare's name. It only appears in zones that have rare maps, like Netherstorm as seen in the screenshot. Hovering over a mob's name in the key will cause the mob's path on the map to start flashing. If you need to read something under the key, it can be toggled by Clicking on the Key Toggle button on the map. The key can be repositioned by just moving your mouse over top of it while holding the shift key and the key will jump to a different corner.
Most map mods like Atlas will inherit the key and overlays from this module. Even Carbonite's map display will show them.
Battlefield Minimap
The small “Battlefield Minimap” (AKA the “Zone Map”) also shows mob paths.
Minimap
All shapes and sizes of minimaps are supported. Rotating minimaps work fine as well.
One feature not shown in the screenshot is a thinner 100 yard range ring around your character. It helps you gauge _NPCScan's detection range, so you can sweep through zones more effectively. This option can be found in the Minimap subsection of the options panel, detailed below.
Options
_NPCScan.Overlay's options can be found under _NPCScan's main options menu, under _NPCScan > Overlay or as its own entry of _NPCScan.Overlay if _NPCScan isn't installed. This panel can be opened with the “/npcscanoverlay slash command, or “/overlay” for short.
The “Always show all paths” checkbox at the top of the pane overrides the instructions of NPC tracking mods like _NPCScan to hide unused paths, and always displays all known paths instead.
The rest of the configuration pane lists each map display's options. You can enable/disable each map from here, as well as configure individual settings for them.
Each map display can have its overall transparency set independently with the “Alpha” slider, so that it doesn't obscure the maps themselves.