Natural Earth for WorldWind as static QuadTileSet

[FrankChendra]

Hi there,

i am a freelance developer based in Düsseldorf, Germany and just came by your site. Thanks for the great maps!

I had some time this weekend and thought about creating tile sets for NASA WorldWind from the natural earth sets you are proposing.

I got a mixed set working, see here for screenshots:

HYP_50M_SR_W

http://www.multimedial.de/share/Shot1.jpg

NE2_HR_LC_SR_W_DR

http://www.multimedial.de/share/Shot2.jpg

If there is interest, I can make proper sets from this. I was just trying out the sets in order to include them eventually in another project.

On that same note, I would be very interested to get the Shape files rasterized, as my solution only supports raster tiles and no ESRI Shapefiles. Can anyone point me to a good tool (preferably open source or low cost) which could render the shape files to bitmaps for tiling purposes?

Thank you very much,

Frank Chendra

[Tom]

Frank,

Thanks for sending the preliminary WorldWind screen shots, which look very promising. My workflow for rasterizing shapefiles to GeoTIFs would involve Adobe Illustrator, MAPublisher, Photoshop, and Geographic Imager software, all of which are pretty expensive.I would think that freeware or shareware exists for accomplishing what you want to do. Let us know what happens.

Tom

[Tom]

Another thought, ask about this on the CartoTalk.com discussion forum.

Tom

[sega sonic]

I recommend you to use the mapnik renderer. It reads vector (incl. shp) as well as raster file, deals with projections, the output rendering quality is very high and it’s easy to script it with python. The styling is done by an XML file. You can get the source or binaries at mapnik.org.

Btw: It’s the rendering engine that OpenStreetMap uses.

[rongcon1]

Frank,

Does your map at 13th zoom look clear? If so which map did you use? I’ve been looking for some good raster world map that I can tile and zoom to at this level without blurring. I’ve tried the one on this site , it’s blurry at about 8th or 9th level.

Also,

Would you or someone in ths forum please provide tutorial on projeccting layers from shp files onto application that runs with World Wind and/or Open Street Map?

Much Appreciated!

Just a newbie at this….

[Nathaniel]

@Rongcon1: The most detailed line work in Natural Earth is designed for 1:10,000,000 (10 million) scale mapping but looks decent until 4 million. That equates to zoom 7 in the Google maps model.

How Can You Tell What Map Scales Are Shown For Online Maps? (ESRI)

http://kelsocartography.com/blog/?p=2407

You’re going to be hard pressed to get good linework at zoom 13 (which is just better than 1:100,000 scale). In the US you could use the map series built at that scale. But your talking a large (in file size) dataset and not global coverage and out of date info.

I don’t have experience with World Wind. Anyone else jump in?

[pangloss]

Hi,

I prepared a tiled image layer of the Natural Earth imagery for World Wind a couple of years ago.

http://forum.worldwindcentral.com/showthread.php?t=15289

It has consistently been one of my most popular add-ons.

I’m more used to working in dimensions and resolutions than scales, so you will have to convert this to 1:whatever. The Natural Earth add-on above is 32K x 16K resolution at the highest level (4 levels, 4×8 x 512px = Level0). WW will accept any 1×2 tiling scheme, 5×10 is the most common.

There are 2 datasets of this type for WW, that I know of. The Demis World Map

http://forum.worldwindcentral.com/showthread.php?t=4528

is pretty nice, but the background map is kind of simple. It goes to nine levels (4×8 base).

There is also a plugin for Microsoft’s Virtual Earth that goes to 20 levels, but crashes the program a lot.

These are both served as tiles.

You will never get anything that large into a manageable package to download if that is what you have in mind. My Natural Earth add-on is ~200 MB (64 MB Installer). It only includes the land areas, overlaid on a small blue texture, to reduce the size.

I take it that you realize the size will quadruple with each level.

btw: Have there been any dramatic changes since then, that I should worry about updating it? It appears that the version that I used (LC_SR_16200 E&W) is larger than the resolutions you currently offer. Unless there were major changes, I’m probably better off with what I have.

Regards

[Nathaniel]

@Pangloss: No need to update to the new version which mostly has edits to make it work better with the new 1:10,000,000 land/ocean mask. If you do use the new linework, it is recommended you use the new raster to be in register, though.

For pixel conversions at zoom level:

Each succeeding zoom level divides the map into 4 N tiles, where N refers to the zoom level. For example, at zoom level 1, Google Maps divides the world up into a 2×2 grid for a total of 4 tiles; at zoom level 2, Google Maps divides up the world into a 4×4 grid for a total of 16 tiles, etc.

(http://code.google.com/apis/maps/documentation/overlays.html#MapTypeZoomLevels)

Zoom 6: (2^6 * 256)

16k pixels.

New Natural Earth is 21,600 x 10,800 so between zoom 6 and 7. Raster scales up pretty well, so when I say zoom 7, it scales up fine to the linework which looks good at zoom 7 but is getting inaccurate (blurry in raster terms) at zoom 8.

Zoom 7: 32k pixel width total (2^7 * 256)

128 tiles wide and tall * 256 pixels per tile = 32k width total.

Zoom 8: (2^8 * 256)

256 tiles wide and tall * 256 pixels per tile = 65k width total.

Someone check me?

http://www.maptiler.org/google-maps-coordinates-tile-bounds-projection/

[pangloss]

Thanks for the information. Initially, I’m most interested interested in the country/province datasets. Most of the available ones have some serious problems. These look quite good! Thanks for releasing them.

[Nathaniel]

@Pangloss: We’ll have better admin-0 out with thematic codes (ISO, FIPS, etc) added on soon. The admin-1 are one of the better ones out there at this scale, but the coding still needs some work. Please let us know any errors you find.

[Author]

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