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Thread: How to make DEMEX based Route?

  1. #11

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    I have download .tif terrain data for indian from USGS website but demex dosen't appear to work. When i choose that file the DEMEX crashes and when i convert it using VTBuidler like Sulivan said. The demex doesen't read data i show black screen like this.
    Screenshot (26).jpg

  2. #12
    Join Date
    Apr 2007
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    Swindon, England
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    Why don't you use hgt data from the Viewfinder site?

    http://www.viewfinderpanoramas.org/dem3.html
    Vern.

  3. #13
    Join Date
    Nov 1999
    Location
    Jacksonville,, FL, USA.
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    Parth----

    When you get that black screen, it is not a valid .tif file. YOU ABSOLUTELY MUST RUN VTBUILDER AS ADMINISTRATOR, or
    it will not work. In my experience, you get an error message and then have to shut down VTbuilder and when you do, you
    have the black screen. If you will send me a private message with a list of the files you need to convert, with your return
    email address, I'll process them and send them to you in a zip file, by way of "WeTransfer". However, for your own good,
    do this:
    Set protections on your output folder to wide open, i.e. read/write.
    Run Vtbuilder as Administrator. Under "layer", select "import data".
    Then under "import data" select "elevation".
    Then select the file to convert.
    After it has loaded, which will take a few seconds-------------
    Select "Elevation" in the border at the top
    Then select "export to"
    Then select "GeoTiff".
    Give the output file a different name than the input file
    and select "Save".

    Now the weird thing is that of 9 files I processed a couple of days
    ago, 3 produced errors, and 6 did not, so a logical assumption was
    that the download was corrupt, i.e. the download from USGS but no,
    I tried those again and they processed without error. So just make sure
    you have output folder protections set to read/write and be sure to
    run VTBuilder as Administrator.

    I don't like the .hgl data because it does not seem to be as high a resolution
    as the geotiff data, which I want to be 1/3 arcsec or better. I only use the
    .hgl data for foreign routes and I have only 2 of those set up to create, both
    in Brazil.

    J. H. Sullivan

  4. #14
    Join Date
    Aug 2002
    Location
    Poteau, OK, USA.
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    Quote Originally Posted by NorthernWarrior View Post
    Why don't you use hgt data from the Viewfinder site?

    http://www.viewfinderpanoramas.org/dem3.html
    It's my understanding that hgt data is right at 90m DEM. SDTS as well as NED can both be had in 10m as well as 30m (for distant mountains). There is a significant detail difference between terrain rendered from 90m DEM compared to 10m DEM when it comes to undulating/mountainous terrain.

  5. #15
    Join Date
    Nov 1999
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    Jacksonville,, FL, USA.
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    I don't know what the specific resolution is for .hgt data but in my experience it is considerably
    less desirable in appearance. I use the 1/3 arcgrid for both types of terrain, although lower
    resolution would be okay for distant mountains.

    J. H. Sullivan

  6. #16
    Join Date
    Nov 1999
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    Jacksonville,, FL, USA.
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    I want to submit a suggestion here. My experience is that USGS reformats their data every couple of years.
    Right now, while it may cause a migraine or two, we can get data, of acceptable resolution, process it with
    VTBuilder, or whatever, and use it, but for how much longer??
    So I submit that all of us serious route builders as well as newbies might want to take a hard look into our
    thoughts and decide what we might produce over the next few years. Then create those route with RGE
    or whatever method we use, and download and process the DEMs and extract the terrain. I have more than
    I will ever accomplish (I'm 81 and I do a few other things besides MSTS) but here is the method I use:

    Create at least a rough outline of your route using RGE and "new route" or TSRE, or whatever you like.
    Digitize the route, at least the track and major roads using your favorite method (Google Earth) and
    bring it up in DEMEX. This will let you know if you have created sufficient (or too many) tiles for your
    marker files. Go back to RGE or whatever and correct your tiles. Once you have done that, use the
    extreme coordinates of the route to select the Geotiff files from USGS. Download those, process them,
    and use them in DEMEX to shape the terrain. At this point the route will probably fit on a CD, so burn
    one and put it "on the shelf". I have about 10 routes "on the shelf". Now, if I know I am close to the
    end of my rope, I will upload those routes to the "unfinished" category, otherwise eventually, I will
    release them, but my plan is to restrict the level of detail, one thing I liked about Bob Wirth's AT&SF
    routes. My wife and children (age 54 & 52) know this and will put the routes in "unfinished" if I get
    a sudden call, and my last Form A and running orders.

    J. H. Sullivan

  7. #17
    Join Date
    Nov 1999
    Location
    Jacksonville,, FL, USA.
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    Parth sent me his two files which he says came from USGS, but when I go to the USGS site, I can
    not find any data from his location, i.e. southern India. The files are valid 1 arc-sec. geotif files
    which VTBuilder reads and writes correctly, i.e. no errors, but when brought into DEMEX the
    result is a black screen with a few vertical lines in it. I suspect he will have to use .hgt data
    from the recommended site.

    J. H. Sullivan

  8. #18
    Join Date
    Nov 1999
    Location
    Jacksonville,, FL, USA.
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    I went to the panorama site and got the .hgt tiles which are the same as Parth's .tif files
    and sent them to him. I did confirm that the USGS site only has the US, some Canada,
    and some Mexico areas, no India locations, so I have no clue where he got the files
    he was trying to use.

    J. H. Sullivan

  9. #19

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    Having some experience sourcing DEM outside of US, the following below is the best data set I am able to find which has global coverage. It is from the SRTM mission and covers most of the world at 1 sec level (30 m resolution), and is in the same HGT format that TSRE uses.

    http://step.esa.int/auxdata/dem/SRTMGL1/?C=N;O=D

    That said, its still very poor compared to anything you guys have in the US. Expect lots of lumps that need to be smoothed out.

  10. #20

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    Quote Originally Posted by NorthernWarrior View Post
    Why don't you use hgt data from the Viewfinder site?

    http://www.viewfinderpanoramas.org/dem3.html
    The 3 second data in the site above is at 90m resolution.

    Since then NASA has also made the 1 second 30m dataset available at a global level.

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