Issue 130 in osm2garmin: Contours are generated in areas of low relief - and are not wanted

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Jul 20, 2014, 11:04:40 AM7/20/14
Status: New
Owner: ----
Labels: Type-Enhancement Priority-Medium Usability

New issue 130 by Contours are generated in areas of
low relief - and are not wanted


I am making maps where I only want minor contours every 100 meters and
major every 500m for the complete map. The problem is that in areas of low
relief (flat areas under 300m? 200m?) (ex. shore areas) the program will
generate minor contours every 10 meters regardless of program settings. In
areas with an elevation above these levels contours are generated according
to program settings. This is easiest to see in the Galapagos Islands (Isla
Genovesa and Rabida) near Lat/Long N00 19.5 / W89 57.5, S00 25.25 / W90 42
but happens in many other areas.

In addition to not providing me the control that over map generation that I
want, the maps appear "inconsistent" with some areas displaying 10 meters
contours and adjacent areas not. Bad maps!

This may be related to the contour generation changes introduced on
2012-02-28 where: "Completely rewritten contours generation procedure.
Contours density is more sensitive to the terrain shape in given area.
Smaller contours interval is set in flat areas." (

Additional Notes -

Changing program options has some effect, but not the control that I need
My settings are contour interval 100/100/500, elevation difference100/5000.
Version 1.2.267 and Java 1.7.055 and Linux 3.11.0-12

If contour generation in flat areas is "hard coded" I need the option to
disable this function either via a check box (preferred) or passing the
program an argument (particularly if this is a quick change). This is an
important issue for me, unfortunately, maybe only to me. :)

I marked this as an enhancement, but...

Thanks, pitney

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Sep 21, 2014, 2:18:40 PM9/21/14

Comment #2 on issue 130 by Contours are generated in
areas of low relief - and are not wanted


Thank you for your reply. I would like to try adjusting the source code to
not create contours in areas of low relief.

I have looked at the source code and have a few questions:

which file/module contains the contour generation code?
where does the contour code start if this is a large file?
which language is the code written in?
will I need to re-compile the code after making changes?

Finally, is there a release available that does not include the updated
contour code?

I remain interested in updating the Users Gude when version 1.3 is released.
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