Simple political/ geographic tileset needed for offline use

[andrewh...@gmail.com]

Hi Cesium community,

I am a newbie to GIS and mapping, and having a lot of fun building a little Cesium app to visualize some data concerning satellite paths. The app needs to work in a completely offline setting, meaning I need all the tiles to be stored locally. The free Natural Earth II tileset, which I believe goes up to tiling level 5, is just fine for the level of resolution needed for this project. But I would really like to have access to political boundaries, waterway names, and things like that. Can anyone suggest a noob-friendly way for me to generate the tileset I need? Even better would be something already created, but I will be happy for whatever help is on offer.

[Mike LP]

Aside from just random googling for tilesets, I would start with open street maps and see if there is something on there that would work.  

[Mark Erikson]

A couple years back I had a similar need.  I took the Natural Earth 110M political boundaries dataset, modified the Cesium "czml-writer" tool to have some better shapefile support and allow filtering out entries based on shapefile attributes, and generated a CZML file that we load up at start time containing vector polylines for the borders .  Sadly, I've never had time to push back my changes to the czml-writer project, but it's something you could look at.  Or, now that Cesium has KML support, there's gotta be a KML file somewhere with labels and borders and stuff.

On Saturday, June 20, 2015 at 8:30:27 PM UTC-4, Andrew H. wrote:

[Andrew H.]

Thanks Mark and Mike!

Following https://groups.google.com/forum/#!topic/cesium-dev/Kq8wORqA09E , I have successfully made an mbox tileset from Maperitive using MapQuest OSM data, and am serving it with Tilestream. It works, kind of... the map looks so different at different zoom levels that draw-in around the sides of the globe is fairly hideous. I will look around for kml support because I think that would look nicer than my current map if it were simply projected on top of Natural Earth.

[Mark Erikson]

Yeah - for something like political boundaries, you're really going to want a vector dataset so that it's resolution-independent, so either CZML or KML format.

[Mike LP]

I wonder if anyone has shared a GeoPolitical czml file.  I'm sure there would be a lot of people interested in it.

[Andrew H.]

OK... I downloaded the world countries kml from here: http://www.rjruss.info/2010/12/free-countries-of-world-in-polygon-kml.html

I changed the alphas of all the polygons to 0, so that the natural earth colors would show through. This is accomplished by doing a find and replace, as follows: <PolyStyle><color>FF => <PolyStyle><color>00 

I also changed some references to an icon that was supposed to load dynamically from someplace that doesn't allow CORS. This is accomplished by doing a find and replace, as follows: http://icons.opengeo.org/markers/icon-poly.1.png => icon-poly.1.png

Now I have roughly what I wanted! : )

Remaining issues include, the text for the countries doesn't look very good. 

[Mike LP]

thanks for sharing that.

[Mark Erikson]

I'd love to share the one I generated, but while realistically no one higher up would ever know I did, I can't actually justify doing so.

Pushing my changes to czml-writer back to the repo has been on my todo list for a long time, but never been able to get it done.

Ultimately, though... all it amounts to is generating a bunch of CZML polylines with the right coordinates.