SRTM data not loading

[BDWorkshop]

What was the source for the DEM files?

I'm not sure I know what you are asking. Where did they come from?

[BoostedFridge]

What was the source for the DEM files?

I'm not sure I know what you are asking. Where did they come from?

Yes. Ie: what website did you get them from? I strongly recommend the USGS national map as your source.

[BDWorkshop]

What was the source for the DEM files?

I'm not sure I know what you are asking. Where did they come from?

Yes. Ie: what website did you get them from? I strongly recommend the USGS national map as your source.

Yes, that is where I got them from.

[BDWorkshop]

Here are the three DEM's I'm working with...
I can't find any difference between them. Railworks refuses to load the bottom one.

[BoostedFridge]

Instead of downloading 1/3 arc second files and then exporting them as 1 arc second, try downloading the actual 1 arc second terrain file for the lat/long square that is causing the crash

[BDWorkshop]

Instead of downloading 1/3 arc second files and then exporting them as 1 arc second, try downloading the actual 1 arc second terrain file for the lat/long square that is causing the crash

That's odd...The 1 arc doesn't work either.

[BDWorkshop]

I downloaded the same height file from a link in the beginning of this thread. That file works. There is a slight difference between the 1 arc and the 1/3 arc files. The area where they join is a bit rough but it can be smoothed out. I still wonder why those DEM's aren't working?

[BoostedFridge]

Strange... The USGS site has never given me any trouble with its files yet. That said, anything is possible.

[MaxQue]

Greetings,

I just finished installing 4,821 of the 1/3 arcsec tiles into a route I'm considering building. My proposed route is 205 nautical miles in length. This is the first time I've tried to do this and this thread was instrumental in getting me up to speed. To even consider undertaking this monumental route-building task, I had to have 1/3 arcsec resolution terrain. I tried using the BILxSTRM.exe to transform the 1/3 arc BIL files to ".hgt" format, but that program generates files that are not compatible with loading SRTM data files directly from the World Editor. It doesn't work.

The ReDem program takes the BIL format files and renders them directly to terrain tiles installable into the route's terrain tiles folder. This was the way to go, at least for me.

Here's what I did:

From the USGS site I used the download map to select and download the 1/3 arc second files I needed in GridFloat format. I got a total of 10 files since my route runs SW to NE.

After downloading, I extracted all the files into one folder. The important extracted files are the very large data files in GridFloat format with the ".flt" file extension.

Using MicroDEM's "Open and Merge DEMs" selection under the "File|Open" menu, I selected & merged four of the ".flt" files into one "BIL" data file, and two sets of three into another two "BIL" files. That game me a total of three BIL files to work with.

Using ReDem, I loaded each BIL file, generated the tiles into a holding folder, then copied them into the route's terrain folder.

Problems:
After loading all the tiles into the terrain folder, I noticed that the terrain looked very workable for laying track, excellent in fact, but there were many gaps of missing terrain tiles. I was doing something wrong. Obviously the ReDem program was not generating all of the tiles I needed. I went back to ReDem and selected to load an additional 5 tiles and while this did help, there was still a lot of missing terrain. After struggling with this over the last several days, I suddenly realized that my route was so long that I did not have enough route markers to allow ReDem to generate all the tiles that were needed. I doubled the number of route markers then re-ran ReDem for all the BIL files and, sure enough, it was generating a lot new tiles while skipping over the previously generated tiles.

Lesson Learned:
The ReDem program is an outstanding tool. My mistake was in thinking that it was building tiles from one route marker to the next. It apparently does not. It merely builds terrain tiles around each marker individually, and you must have route markers sufficiently close together so the tiles overlap to create a seamless terrain. Note to Self: Read the help file carefully...

Hope this might help someone and save them a few days of banging their head against the wall.

Also, thanks to BNSFSubDivision for posting his ideas & PDFs on this thread. I knew nothing about any of this stuff when I started to try and load terrain last week, and now... I are a expert!!! ( Kidding, of course...)

[bnsfsubdivision]

Greetings,

I just finished installing 4,821 of the 1/3 arcsec tiles into a route I'm considering building. My proposed route is 205 nautical miles in length. This is the first time I've tried to do this and this thread was instrumental in getting me up to speed. To even consider undertaking this monumental route-building task, I had to have 1/3 arcsec resolution terrain. I tried using the BILxSTRM.exe to transform the 1/3 arc BIL files to ".hgt" format, but that program generates files that are not compatible with loading SRTM data files directly from the World Editor. It doesn't work.

The ReDem program takes the BIL format files and renders them directly to terrain tiles installable into the route's terrain tiles folder. This was the way to go, at least for me.

Here's what I did:

From the USGS site I used the download map to select and download the 1/3 arc second files I needed in GridFloat format. I got a total of 10 files since my route runs SW to NE.

After downloading, I extracted all the files into one folder. The important extracted files are the very large data files in GridFloat format with the ".flt" file extension.

Using MicroDEM's "Open and Merge DEMs" selection under the "File|Open" menu, I selected & merged four of the ".flt" files into one "BIL" data file, and two sets of three into another two "BIL" files. That game me a total of three BIL files to work with.

Using ReDem, I loaded each BIL file, generated the tiles into a holding folder, then copied them into the route's terrain folder.

Problems:
After loading all the tiles into the terrain folder, I noticed that the terrain looked very workable for laying track, excellent in fact, but there were many gaps of missing terrain tiles. I was doing something wrong. Obviously the ReDem program was not generating all of the tiles I needed. I went back to ReDem and selected to load an additional 5 tiles and while this did help, there was still a lot of missing terrain. After struggling with this over the last several days, I suddenly realized that my route was so long that I did not have enough route markers to allow ReDem to generate all the tiles that were needed. I doubled the number of route markers then re-ran ReDem for all the BIL files and, sure enough, it was generating a lot new tiles while skipping over the previously generated tiles.

Lesson Learned:
The ReDem program is an outstanding tool. My mistake was in thinking that it was building tiles from one route marker to the next. It apparently does not. It merely builds terrain tiles around each marker individually, and you must have route markers sufficiently close together so the tiles overlap to create a seamless terrain. Note to Self: Read the help file carefully...

Hope this might help someone and save them a few days of banging their head against the wall.

Also, thanks to BNSFSubDivision for posting his ideas & PDFs on this thread. I knew nothing about any of this stuff when I started to try and load terrain last week, and now... I are a expert!!! ( Kidding, of course...)

Hey welcome to the forum!

Great to hear you managed to set up your terrain at pretty much the first shot. Many people struggle with it for days and can't get it to work properly. Also thanks for summing up the steps you did in short, I'm sure this Information will help out a few people out there new to this stuff.

[krellnut]

So I got 1 second arc files to load into game, but not 1/3. Am I correct in assuming the only way to get 1/3 files to load is by using Redem? I tried using Redem, but it wants me to load route markers, and I don't know how to make them. Anyone know how to make the necessary markers to use in ReDem?

[BoostedFridge]

So I got 1 second arc files to load into game, but not 1/3. Am I correct in assuming the only way to get 1/3 files to load is by using Redem?

Correct.

I tried using Redem, but it wants me to load route markers, and I don't know how to make them. Anyone know how to make the necessary markers to use in ReDem?

In order to make the route marker file for redem, you are going to need to make either a .csv file, or .gpx file with the Longitude, Latitude, and name of the marker location for EACH marker location along your route. As MaxQue noted above, ReDem builds the terrain in a radius around EACH marker file. So it is absolutely CRITICAL that your markers are close enough to each other that the radii of terrain around each marker overlaps. ie: either make the "Suggested DEM bounds" # of tiles higher, or place your markers very close together. For my Siskiyou route I used a range of 7 tiles around each marker, and made sure the markers were approximately 7-8 miles apart. That 7-8 miles is in a straight line between the two markers, NOT by whatever route the track takes!

First, you will need to map out your route using GoogleEarth. Place Marker files along the length of your route. (see below)

Marker File 1.jpg

Marker FIle 2.jpg

As noted above, the distance between markers should vary depending of the 'Range' you choose in the 'Suggested Dem Bounds' section of Redem. The greater the number of tiles 'Range' you choose, the more total tiles will be created. If your route is in a very open terrain, where you can see for miles, or if the route you are making is very straight, I would suggest a higher number of tiles for your 'Range'. ...we'll get to that further below.

After you have created all of the marker files for your route in Google Earth, you will need to save them to your computer.

Marker File 3.jpg

Marker File 4.jpg

- CONTINUED IN POST BELOW -

[BoostedFridge]

- CONTINUED FROM ABOVE -

Next you have to condense the data from all of these files into a single file that ReDem can read. You can do this in two different ways. You can either create you own .csv file in notepad, or use a program or website to create a .csv or .gpx file from your markers. I will show you both ways below.

The quickest method is to use a program or website such as: http://www.gpsvisualizer.com/convert_input

Load the website at the link above. Follow the instructions in the pictures below.

Marker File 5.jpg

Marker File 6.jpg

Marker File 7.jpg

You can load that file in the 'Markers' section in Redem.


As an ALTERNATIVE to creating a GPX file in the above method, you can create your own .csv file with the marker data. You do NOT need to do the steps below if you already created a .GPX file. I am showing this simply as an alternative method.

Open the program 'Notepad'. In the body of the file, type the LONGITUDE, LATITUDE, and NAME of each marker location, separated by commas, with no spaces. See picture below.

Marker File 8.jpg

Marker File 9.jpg

The .CSV file you have just made can then be loaded into ReDem at the appropriate time in the process.

The only advantage to this method (in my opinion) is that you can load ALL of your markers into one file. Due to the limitations of the GPS Visualizer site used in the other method, only 10 markers can be added easily per GPX file. You then have to go through the Redem multiple times if you have more than 10 markers on your route.

With either of these marker files, you can now proceed through the Redem process.
The ReDem instructions can walk you through that. ----> http://www.zugware.com/documents/redem_manual/

Hopefully this answers your question, and is of use. If anyone would like, I can continue through the ReDem process in greater detail.

[krellnut]

Hopefully this answers your question, and is of use.

Totally answers my questions. Thank you so much for taking the time to answer in such detail, pictures also are a great help.

If anyone would like, I can continue through the ReDem process in greater detail.

I think I'm going to make a csv. file. If I can't get it to work, I might come a knocking.

[bnsf9580]

So I got 1 second arc files to load into game, but not 1/3. Am I correct in assuming the only way to get 1/3 files to load is by using Redem?

Correct.

I tried using Redem, but it wants me to load route markers, and I don't know how to make them. Anyone know how to make the necessary markers to use in ReDem?

In order to make the route marker file for redem, you are going to need to make either a .csv file, or .gpx file with the Longitude, Latitude, and name of the marker location for EACH marker location along your route.

Well I made the .csv file, and it works. The only problem is I still need to import the .bil files into ReDem, and I can't because the conversion tool doesn't convert them. Is there another tool I can use to convert my .hgt files into .bil files for import?