[mkgmap-dev] Holes in the Sea

Wed Feb 29 10:21:02 GMT 2012

> Use --description in your splitter args, otherwise if there are no places
in that
> tile, the splitter takes the  description of the previous tile.

When I use --description=somename  then the --geoname-file option does not
work anymore. All tiles are named "somename" then.

> 
> Did you use --no-trim in your splitter parameters? Maybe this helps to
cover
> some holes.

I did. Without this option there  are many more holes.

After viewing the tiles with Josm, I think I understand the problem now:

There are coastlines in most of the hole-tiles but only because I use
--overlap. The part of the tile that is actually used later does not touch
the coastline. Only the --overlap area does, and will be cut away later. So
a coastline in the overlap area seems not to be enough for --generate-sea to
recognize the tile as sea.

After trying lots of different --max-nodes settings I did not find one that
produces a tile pattern that is completely free of empty tiles. So I will
need to find a workaround.

Modifying areas.list manually could be one way. But I do not really know how
to. And it will be difficult because the bigger hole-tiles have many small
neighbor-tiles which are again somehow nested to each other. So it will be
necessary to change lots of tiles to make them match to a sea-tile made
bigger manually.

It might be easier to tell mkgmap which empty tiles are sea. How can I do
that?

https://wiki.openstreetmap.org/wiki/User:RheinSkipper