| Re: Plotting 'continents' in object graphics... [message #41259 is a reply to message #41124] |
Mon, 04 October 2004 13:35   |
Mark Hadfield
Messages: 783
Registered: May 1995
|
Senior Member |
|
|
Rick Towler wrote:
>
> Come on people! If there is one thing we have learned is that you can
> do just about anything in OG if you are willing to waste the time :)
>
> Someone with some mapping skills could whip up a set of verts and
> connectivity given the many coastline databases on the web. It just
> needs to be done once and it has probably been done already. Anybody
> care to share?
I have some code to pull coastline data from the GSHHS dataset:
http://www.ngdc.noaa.gov/mgg/shorelines/gshhs.html
The routine accepts a pair of longitudes and latitudes defining a
rectangular area, then pulls out all coastline segments intersecting
(and maybe surrounding) this rectangle, tessellates them and clips them.
This is not done once and for all, it's done every time the routine is
called (but it does save the results in a temporary file and re-use that
if possible).
It works very nicely for my needs, but I mostly draw maps of the
Southwest Pacific. It would not work so well for maps of small regions
of large continents, because if you want to draw a map of, say, the
northern tip of Denmark at high resolution, you first have to read &
tessellate all of Eurasia!
I could publish my routines if there's any interest...
--
Mark Hadfield "Ka puwaha te tai nei, Hoea tatou"
m.hadfield@niwa.co.nz
National Institute for Water and Atmospheric Research (NIWA)
|
|
|
|
comp.lang.idl-pvwave archive
Members
Search
Help
Login
Home
