Contour lines via SRTM files in Osmand

[Hardy]

Hello Ives,

I love the contour line functionality via the SRTM files you provide
at http://www.pistes-nordiques.org/osmand-page/Osmand-SRTM-contours/,
and have also adapted the rendering syle of your winter-renderer (the
one I sent you as "depends" renderer) for the countour lines in
Osmand's default renderer (including switch to show or not show
contours in Settings/Maps).

Now all it takes is to have an SRTM.obf file in you osmand folder, and
activate the contour lines in default renderer-specific settings for
some profile like "pedestrian".

I have, however, a few observatsion and am not sure how much of that
is bugs and/or could easiliy be fixed:

(1) Your SRTM files slightly overlap in areas around international
borders. Since the rendering style for the countour lines involves
some transparency, the lines appear in more solid orange where the
overlap happens. My current workaround is to have only one SRTM file
active at any time. Can the files somehow be 'cut' more precisely?

(2) In a number of places, the contour lines seem to form
'vorteces' (e.g. several around lat=47.5906, lon=12.3248). In those
places, all contour lines just "wiggle around some polygon (frequently
diamond-shaped.) Is this a bug in the SRTM files?

(3) I frequently encounter "Out of memory" errors when having SRTM
files active (I think particulary when there is more than 1). Map
rendering stops then and I have to re-start Osmand. Could this be
related to (1) or (2), or do we know of some other way to fix it?

Thanx!
Hardy

[andre van atten]

Hi,

The shift near borders and artifacts like diamonds and vorteces occur for the main part in Srtm2Osm I think (while translating), and there are also problems in the data itself.
The memory problems occur mainly in very dense areas. It takes a lit of resources to render many contourlines, and Android apps have memory quota.
That's why I like the combination of contour lines and hillshade in one tile package (sqlite). I like the solution as in cyclemap, and wandelreitkarte. If someone would be able to download pre-fabricated transparent packages of certain areas, Osmand could show them as an overlay with vector maps and other tile maps. That gives fabulous results, and there are no memory problems. Still one of my wishes to make such a download server with hillshade and contour packages. However, we have to make one step at a time.

Andre

Op 27 dec. 2011 18:40 schreef "Hardy" <hm.gg...@googlemail.com> het volgende:

[Yves CAINAUD]

The thing is that I use Osmconvert to cut the contour at the border. If a contour is closed around the border, Osmconvert remove the outside nodes but keep this contour closed. Unfortunately no ready-made tools exists to open this polygons at the border. Would be the same with osmosis.

The border I use come from Cloudmade or Geofabrik (.poly), they should be the same used for country extracts on these sources. Of course, the more precise they are, the longer the extract, and I don't think the osm database administrative lines without any simplification would be useable for this cut-out.

Yves

2011/12/27 Hardy <hm.gg...@googlemail.com>

[Hardy]

Thank you Yves and Andre for your replies! Let's keep working on it,
we already have made GREAT progress in recent months.

I really like Andre's dream of a transparnt contour+hillshade overlay!
Let's make it happen! :-)

On 27 Dez., 19:45, Yves CAINAUD <yve...@gmail.com> wrote:
> The thing is that I use Osmconvert to cut the contour at the border. If a
> contour is closed around the border, Osmconvert remove the outside nodes
> but keep this contour closed. Unfortunately no ready-made tools exists to
> open this polygons at the border. Would be the same with osmosis.
>
> The border I use come from Cloudmade or Geofabrik (.poly), they should be
> the same used for country extracts on these sources. Of course, the more
> precise they are, the longer the extract, and I don't think the osm
> database administrative lines without any simplification would be useable
> for this cut-out.
>
> Yves
>

> 2011/12/27 Hardy <hm.gglm...@googlemail.com>

>
>
>
> > Hello Ives,
>
> > I love the contour line functionality via the SRTM files you provide

> > athttp://www.pistes-nordiques.org/osmand-page/Osmand-SRTM-contours/,

> > and have also adapted the rendering syle of your winter-renderer (the
> > one I sent you as "depends" renderer) for the countour lines in
> > Osmand's default renderer (including  switch to show or not show
> > contours in Settings/Maps).
>
> > Now all it takes is to have an SRTM.obf file in you osmand folder, and
> > activate the contour lines in default renderer-specific settings for
> > some profile like "pedestrian".
>
> > I have, however, a few observatsion and am not sure how much of that
> > is bugs and/or could easiliy be fixed:
>
> > (1) Your SRTM files slightly overlap in areas around international
> > borders. Since the rendering style for the countour lines involves
> > some transparency, the lines appear in more solid orange where the
> > overlap happens. My current workaround is to have only one SRTM file
> > active at any time. Can the files somehow be 'cut' more precisely?
>
> > (2) In a number of places, the contour lines seem to form
> > 'vorteces' (e.g. several around  lat=47.5906, lon=12.3248). In those
> > places, all contour lines just "wiggle around some polygon (frequently
> > diamond-shaped.) Is this a bug in the SRTM files?
>
> > (3) I frequently encounter "Out of memory" errors when having SRTM
> > files active (I think particulary when there is more than 1). Map
> > rendering stops then and I have to re-start Osmand. Could this be
> > related to (1) or (2), or do we know of some other way to fix it?
>
> > Thanx!

> > Hardy- Zitierten Text ausblenden -
>
> - Zitierten Text anzeigen -

[Yves]

Sqlite raster package are big, so for that we need a ui where the user can request a package, then download it later.
Any idea avoiding admin boundaries?
Yves
--
Envoyé de mon téléphone Android avec K-9 Mail. Excusez la brièveté.

Hardy <hm.gg...@googlemail.com> a écrit :

[szimszon]

About out of memory issue: http://code.google.com/p/osmand/issues/detail?id=705 (Won't fix)

[Victor Shcherb]

What do you want to say?

Victor

2011/12/29 szimszon <szim...@gmail.com>

[szimszon]

Nothing. Just put a relevant issue link to this thread.