September 12, 2021 um 12:16 #44739
Is there any information somewhere on the site on how the OpenAndroMaps are created?
I mean hardware, software, configurations used?
Why? Do I want to make my own version of OAM. Absolutely not.
I am trying to create maps for the Wahoo line of bike computers. They come with their own maps but these are very rarely updated so there is „a demand“ for updated maps.
Now I have already, with the help of others, created a python program that creates the maps needed. Basically map files of x/y tiles at zoom level 8. But I am searching for information how and what other people are doing/using to make it faster/better etc.
Right now (btw I am on windows) the program downloads the countries needed from Geofabrik (osm.pbf files), converts them to o5m using osmconvert, strips unneeded information using osmfilter and then converts them back to osm.pbf format. Then it creates land and sea for the wanted tiles and splits the tiles from the filtered countries‘ osm.pbf files. Finally the land, sea and map tiles are merged using Osmosis and Osmosis with the mapwriter plugin is used to create the final tiles.
Again this works but is ehh not fast. But what I don’t understand for example is that if I look at the mapsforge creator project they through whole counties at the mapwriter plugin. If I do this with a single tile, without filtering it first, it already crashes (no, no out of memory). But somehow you manage to make whole country maps too.
I also have a postgresql db with the planet file (created with osmosis) in it but when I try to extract a singe tile of map data it takes about 2 hours! Totally unusable. But other seem to be able to use these db’s just fine.
Sorry for making this a long post but in short, any background information would be welcome!September 12, 2021 um 12:53 #44742
Hi Erwin, first of all let’s understand what makes those Wahoo bike maps special (and different from OAM with Locus e.g.):
– appearance / information
— selection of information
— user choices
– technical specialities
— your comments include tiles (pointing to ratser maps with PNG/JPG tiles) but also mapwriter, which typically produces .map vector maps. Or did I miss something here?
— any specialities beyond?
MichaelSeptember 12, 2021 um 16:26 #44744
Thanks for responding. Maybe I was not clear enough, my question is not about appearance, coloring etc. That has been taken care of and working at this point. An other guy in our little group made a tool to „extract“ the poi’s, ways and zoom-appear levels used by Wahoo. I adapted the tag-mapping file used by mapwriter to match and think improve it.
Wahoo puts a lot of poi’s in the map files for example but does(/can’t) use them on the actual devices and is well… doing some weird stuff there. The simplest example being they include a lot of poi’s for shops but leave out bicycle shops. Bit strange for a bicycle computer. To keep the files relatively small they then use a high simplification factor in the mapwriter. I leave out anything their rendering theme does not use and without simplification get a better looking smaller map!
But again, not the question.
I refer to the files as map „titles“ because the x/y coordinate system is to my knowledge referred to as slippy tiles.
The Wahoo devices are running android and have a folder structure consisting of zoom level/X/Y.map. The zoom level is fixed at 8 so that the whole globe is 256 by 256 tiles. So each x/y coordinate has its own map file/tile.
My questions are:
– How do the people here, and elsewhere, manage to create map files for whole countries when I have to struggle to create map files for small parts? On the one hand just being curious and more importantly wondering if maybe there are better alternatives to the software I am using. The development of Osmosis and mapwriter seems to have pretty much stopped years ago. I can’t use Osmium because its Linux only (again, as far as I know).
– What is the data source? Are these also the Geofabrik files? (or a similar site) Or is a postgresql db being used and if so, how is data imported/extracted and how long does this take. As I said, 2 hours for a single tiles map data is not usable.September 12, 2021 um 20:45 #44748
sounds like there is a hybrid of x/y breakdown that you normally see for raster type files (PNG or JPG) and mapsforge .map vector maps. Interesting indeed. Never saw such before.
Your questions from the latter paragraph Christian can answer in more details, but the fundamental answers I may give you as well.
He uses osmosis mapwriter and uses those pbf files as a base. Of course filtering, tag mapping etc. etc.
So your toolset is pretty much the same. The reason why your setup breaks I cannot see, though, sorry.
Christian, any typical traps you know?
MichaelSeptember 13, 2021 um 12:16 #44761
I also know the 256×256 (pixels) tile system from raster files. I am sure it was the inspiration for this solution. On these little bike computers it is a way to keep the memory usage down I guess.
I had hoped to get clues to the existence of other faster tools. Splitting/cutting these tiles from large osm.pbf files like Russia, Canada etc is very time consuming. I heard Osmium is a lot faster there but I seem to be stuck with java/Osmosis.
I expect the big difference to be that you guys are on Linux, mapping is a real Linux thingy it seems, and are able to through a lot of memory at it
But if Christiaan or somebody else knows something that makes the windows mapping live easier…
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