Creating very large map at once is not recommended. The maps for GPS
are supposed to be created by tiles (separate img files) that are
later merged into large GMAPSUPP.IMG file. There are multiple factors
affecting the max. size of single tile (img file), mostly imposed by
file format - cities number, binary file size, etc. While overall
GMAPSUPP file can have virtually any size, the child img files are
limited to about 16-20 megabytes each (max 16 MB binary file + text
labels and other sections). Area of the map is not very important in
map splitting to tiles, but large maps (larger than 22.5 Lat/Lon
degree) are coded with lower coordinate accuracy by Mapwel.
Current version of Mapwel does not have tool to calculate if map in
the work area will fit into single img file, but I will consider
adding such tool.
In general, I would recommend to create tiles only up to 100x100 km
large. To ensure map consistency between the tiles (especially in case
of routing maps), I do recommend the following: 1. place (any) POIs to
all border nodes, use snap to nodes option to ensure precise position.
2. Save copy of the map with these POIs, erase all other objects and
leave only 'border' POIs there. 3. Merge the 'border' POIs file to
next tile map and use these POIs to place border nodes in this tile
precisely. 4. Delete POIs. This approach helps to achieve consistency
between the map tiles.
I plan to add more sophisticated tools for map clipping and border
nodes alignment in a near future. Above guide is a work-around for the