I am in the process of creating a gis map of Toril, starting from the Faerun Continent. (More details are in this question on GIS.SE: Starting a QGIS project for a fantasy world map from raster images.)
One commenter asked if I could share this on Google Earth; however, I have no idea of the legal restrictions on using this material.
Let's say I create a Faerun map completely from scratch; it would be based on copyrighted material, which will be used only as reference and will not be republished in the final work, but obviously I will put in my maps everything related to mapping. Can I distribute it freely?
For example, I want to place Phandelver on the map, so I'll start gathering everything geo-related from the adventure book, scan it, and retrace it all in QGIS (the geographic information system software I am using), I will not include any of the published maps in the final result.
The final result would be a browsable and zoomable Google-Earth-like map.
In the scope of what I want to do, I think the larger question is: Are Toril, Faerun, and all of the Forgotten Realms geographic information free to use?
Specifically, are the geographic coordinates of mountains, rivers, hills, roads, cities (and the size and shape of the buildings, monuments and roads in them) under copyright?