Sometimes you may want to add tracks to Fog of World manually. For example, you may want to add where you had been before you installed the app, or you may want to fix incomplete tracks recorded during weak GPS signal.
One simple way is to use the GPS Visualizer website (http://www.gpsvisualizer.com/draw/). Click the trk on the top-right block and start drawing your tracks on the map. You can also modify the track or move the map region at any time.
Once done, simply click the GPX button to download the GPX file. Then you can import the GPX file to the app through any cloud storage. Please note that in order to prevent from importing inaccurate tracks, the distance between two consecutive locations cannot be longer than 10 kilometers, or that part of tracks will be ignored while importing.
Special care is required for China
The situation will be more difficult if you are trying to draw tracks in China. This is because China uses its own GCJ-02 coordinate system due to political reason (the rest of the world uses WGS-84 coordinate system). When you are using Google Maps, it means that the map is actually shifted in mainland China (not including Hong Kong and Macau). But the satellite map layer is not affected, so you don’t need to worry about it if you are drawing tracks along satellite map layer. Take a look at the picture below, if you are using hybrid mode, the roads and the satellite images are not aligned.
As a result, you have two choices to draw tracks in mainland China.
(A) Always draw your tracks using satellite images.
(B) If you are drawing along roads, append `@GCJ02` at the end of your GPX filename. That way, Fog of World knows the file only contains locations in the GCJ-02 coordinate system, and those locations will be translated to the WGS-84 coordinate system while importing. For example,
track.gpx should be changed to
In case you might regret the tracks just imported, it’s highly recommended to sync with any cloud storage (except iCloud) before you import any GPX or KML file. That way, if you are not happy about the results, you can simply delete and reinstall the app (for erasing data), then sync with same cloud storage again to get your original data back.
PS. On Android, you can erase the app data by “Settings > Apps & notifications > Fog of World > Storage > Clear storage.”