[Marble-devel] Elevation model

[Niko Sams]

> Based on SRTM data files (hgt) you are creating image tiles,
> those image pixel values are set accordingly to SRTM height value.
> In ElevationProfilePlugin, for calculating a profile, the height values are
> extracted from the image pixel values.
>
> What is the advantage to go this way ?
a) because of the size of the tiles (an image cover a smaller area
than a hgt file,
in worst case situation you would need 4 such tiles in memory which is
quite a lot
for esp. mobile devices)
b) to be able to reuse the existing loading code (+caching, scaling, etc)

> Why not simply reading the height value directly from the hgt files ?
> Are this new image tiles additional used for some kind of blending like it
> is done currently with the hillshading tiles?
the data is unmodified, just converted. It would be possible to use hgt files
direclty - with the disadvances above.

cheers,
Niko