POV-Ray : Newsgroups : povray.newusers : converting DEM to height field : Re: converting DEM to height field Server Time
5 Sep 2024 14:23:02 EDT (-0400)
  Re: converting DEM to height field  
From: Josh English
Date: 17 Jul 2000 13:32:39
Message: <3973439D.36885785@spiritone.com>
Is this on a Macintosh? Becasue I use MacDem with success and ease. I do
need to use a few other programs as well, tho. Here's what I do.

1. Go to http://edc.usgs.gov/doc/edchome/ndcdb/ndcdb.html
2. Click on 1:24,000 DEM.
3. Click on ftp via... ( I use ftp by graphics personally)
4. Eventually you will have an ftp link to a specific file that is named
10.2.1.1005691.tar.gz or something. Save this file to a new folder
somewhere.
5. Open the file with MacGzip ( downloaded from the Info-Mac HyperArchive)
This converts the file to a .tar file.
6. Extract the .tar file with tar (also downloaded form the IMHA) this will
place a large group of files in the folders. Most of them have .ddf
extensions
7. Open MacDem ( dld form www.treeswallow.com/macdem)
8. Open any of the .ddf files with the "Import STDS DEM..."
9. After a bit of processing you will have a small window with the color
data.
10. Select "Export POV Targa" from the file menu. This saves a .tga file
and a .pov file that you can start working with.

Be careful, since sometimes the output targa file pov uses has the exact
same name as the targa file MacDem outputs, thus causing problems. Chekcing
the filenames first should work.

Okay, I'll grant that this isn't easy at first, and it took me a bit of
experimenting to figure out, but it's the fastest way I've found

Josh


Eric Fielding wrote:

> Does anyone have a program or code fragment (C or Fortran) to convert a
> "raw" Digital Elevation Model to one of the height_field formats that
> POV can use? I have MacDEM, but it only reads the standard USGS DEM
> format or ASCII text PGM files.
>
> It seems a bit inefficient to store a DEM with 16 bits per sample in a
> 24-bit per pixel TARGA or PNG or PPM image, but I guess those formats
> contain the image size in a convenient form.
>
>                                         ++Eric

--
Josh English -- Lexiphanic Lethomaniac
eng### [at] spiritonecom
The POV-Ray Cyclopedia http://www.spiritone.com/~english/cyclopedia/


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