[Marble-devel] Map Processing Question

[Torsten Rahn]

Hi,

On Monday 06 October 2008 05:26:42 Danuvius wrote:
> Greetings, lofty KDE Marble Devs!
>
> Can anybody advise me on how I could programmatically create an overlay (to
> work with Marble) consisting of a 10 km "coastal band"?

Not easily. We are right now working on getting KML Polygons working in SVN. 
That way it should become possible to create a KML outline / semitransparent 
polygon. However of course you'd need to generate the vector polygons somehow 
yourself.

I'd also like to add bitmap overlays but I guess we won't be able to deliver 
that feature for KDE 4.2.  :-(  

> Basically I want to highlight--as precisely as can be done--all land that
> is less than 10 km from the ocean or ocean-connected seas.  (Basically the
> two "inland" Asian seas do not count, nor do lakes and rivers.)  Doing this
> with a flat map is difficult enough (although I have done it)... 

Well, how have you done it before? Using bitmaps?

> If this is basically impossible, can somebody suggest some way to achieve
> the same ends?  Arguably an impractically huge (highest resolution Blue
> Marble size) political map would do the trick.  I already have a Python
> program that can create such a highlight layer from a properly preprocessed
> Robinson projection map.  But as far as I can tell, sufficiently high

Well the "default" source projection for bitmaps is plate carree / the 
equirectangular projection.

If you haven't done so you might want to have a look at my blog series which 
might serve as a technical introduction to Marble:

http://www.kdedevelopers.org/node/3269
http://www.kdedevelopers.org/node/3272
http://www.kdedevelopers.org/node/3275

(however I'm not sure whether it's useful for your question)

Regards,

Torsten

> resolution political maps don't exist outside of Marble, Google Maps/Earth,
> NASA's Worldwind and similar programs.
>
> I would be immensely grateful if somebody could point me in the right
> direction.
>
> Respectfully,
>
> Danuvius