heightfield

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raphael raphael
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heightfield

Is there a way to display heightfield data ? (as a mesh)
From a remote source or a local one (DTED or SRTM) ?
jasonbeverage jasonbeverage
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Re: heightfield

Hi Raphael,

You should be able to display local heightfield data using the GDAL plugin.  See (http://wush.net/trac/osgearth/wiki/TileSourcePluginGDAL) for documentation.  You can just change <image> to <heightfield> and osgEarth will use the input file as a heightfield.

All other plugins should also be able to pull heightfield data from the web as well.

One tip though when using heightfield data, most drivers default to 256x256 tiles, which is great for imagery but overkill for terrain.  You can reduce the terrain sampling for most plugins using <tile_size>32</tile_size>.

Good luck!

Jason

On Fri, Feb 13, 2009 at 12:57 PM, raphael (via Nabble) - No Reply <[hidden email]> wrote:
Is there a way to display heightfield data ? (as a mesh)
From a remote source or a local one (DTED or SRTM) ?


View message @ http://n2.nabble.com/heightfield-tp2322697p2322697.html
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markus markus
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Re: heightfield

Hi Jason,

I tried to cache the  heightfield data in heightfield.earth test by adding:

    <cache type="tms">
      <path>cache</path>
    </cache>

it is storing downloaded images in 2 directories. One for image data and one for the heightfield images. When I restart the app, it is taking the imagery from local cache, but the heightfield images are  downloaded from net again.

What do I need to add to heightfield.earth test for loading  both images & heightfield images from local cache ?

Thanks, markus
jasonbeverage jasonbeverage
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Re: heightfield

Hi Markus,

If you add the cache block you posted to the root map element, it should cache both heightfields and images to the "cache" folder.  One thing to note though, OSG 2.6.1 has issues writing 16 and 32 bit image formats for most formats.  DDS is one format that works well for caching heightfields in 2.6.1.  OSG 2.8 should cache properly uses the tiff format.  You can override the format used by the cache by adding this to the heightfield element:

<cache>
  <format>dds</format>
</cache>

Can you post your whole .earth file so we can take a look at it?

Thanks,

Jason

On Thu, Feb 19, 2009 at 5:08 PM, markus (via Nabble) - No Reply <[hidden email]> wrote:
Hi Jason,

I tried to cache the  heightfield data in heightfield.earth test by adding:

    <cache type="tms">
      <path>cache</path>
    </cache>

it is storing downloaded images in 2 directories. One for image data and one for the heightfield images. When I restart the app, it is taking the imagery from local cache, but the heightfield images are  downloaded from net again.

What do I need to add to heightfield.earth test for loading  both images & heightfield images from local cache ?

Thanks, markus


View message @ http://n2.nabble.com/heightfield-tp2322697p2355752.html
To start a new topic under osgEarth, email [hidden email]
To unsubscribe from osgEarth, click here.


markus markus
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Re: heightfield

Hi Jason,

thank you, now it works :

<cache>
<path>cache_dds</path>
  <format>dds</format>
</cache>

After adding the tag <path>cache_dds</path> everything works fine. osgearth is  caching  as dds images. Cached tiles are loaded from local after restart.


regards, Markus
franz franz
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Re: heightfield

Hi guys,

Can you tell me which strm data you use  ?
I've been trying strm03 and strm30 but the visual result is not good.

thank you
gwaldron gwaldron
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Re: heightfield

http://srtm.csi.cgiar.org/

Good because they processed the data to remove most if not all no-data values.

Glenn
Glenn Waldron / Pelican Mapping