TransDEM Forum

Hi,
Ive got a bit of a problem but I have no idea why it has occurred. Ive created a map without problem and have exported the map and track spline with the 3-dimentional vector data set at its default settings when the 'adjust terrain elevation' option is selected. No problem there. But when I open the route in Trainz I do have a problem. The terrain is correct but the vast majority of the track is sat at 0.0 instead of following the terrain and creating the cuttings and embankments. I say vast majority because there are a couple of small stretches of track at their correct heights. The track spline was all set down on the same route and I have no other routes set (for roads etc). What has gone wrong and how can I correct the problem?
Note: I did do an experiment first with a small portion of the area to make sure it would work ok and that came out as I expected it to. So I cannot understand what has happened. Any clues please?

What is the source of your 3D vector data?

Ive been using the built in open street maps. Funny thing though. I copied the whole contents of the folder into a new folder and it worked ok. So I am putting this down to a bugged folder.

Strange indeed. What you draw in TransDEM itself, tracing on top of OpenStreetMap or other raster maps, will be 2D by nature. You can add pseudo-3D during export to Trainz, when enabling "Adopt terrain elevation". (For export to TS12 this is made active by default, I think.) But European DEM data usually isn't detailed enough to form cuttings and embankments.

If you import native vector data from external map sources, including OSM via JOSM, it will usually be 2D. You might be lucky enough to have a close relationship with your favourite railway company. In this case you may have access to their infrastructure CAD data in 3D glory, but normally you won't.

Thanks. Im not getting brillant results - the cuttings are rather shallow and the embankments are usually a little low but I have yet to play around with the settings.
Im also considering whether or not I can gain access to any of the wms sites that are free to academics. I have a couple of contacts in a couple of universities but whether they have access to this data I dont know. But no harm in asking. I do have a question though in regards to this sort of data. There seems to be a lot of different types for different purposes. Which ones would suit our needs best?
Finally as for network rail, well again I can but ask cant I?

thanks
Antony

WMS is good for raster images, unfortunately not for vector data.

There is no uniform standard for vector data. Several file formats coexist, some originating from ordinary desktop graphics, some from CAD and others from cartography and GIS. Even more complicated is the search for vector data sources. While many countries, surveying agencies and transport infrastructure owners like railway companies will have completed digitizing their data in the last decade, the data is rarely available to the public, at least not for free. Furthermore, the majority of the is data will still be 2D.

The 3D shaping capabilities in the TransDEM vector data export were originally added to satisfy my curiosity whether it can be done at all and what the output would be like. To create my test data I went the DIY way.

I used an external CAD like track laying editor and tool-set which comes with the German rail simulator Zusi (http://www.zusi.de). Those tools were quite difficult to use and no proper English interface or documentation exists but they produced superb quality 3D vector data. The next version of Zusi, currently only available to industrial and research projects, has a much more user friendly track laying CAD tool. However, license restrictions might prohibit its use for non-Zusi projects.

There used to be a CAD tool for model railway layouts which was also capable of generating 3D data and export it to a common file format but I don't know whether that's still available.

I have some vector data in to following formats *.prj *.shp and *.shx Can they be used in transdem at all? Or is it possible to convert them to a format that can?

Thanks
Antony

.shp is the ESRI shape vector data format, one of the first GIS file formats on the planet. It comes with .shx and sometimes with .prj companions. TransDEM can read .shp in all TransDEM supported map projections. Normally, .shp is lat/long WGS84. UTM or national coordinate systems were not part of the original specification. They later added the .prj file with projection information. TransDEM, however, does not currently read the .prj file. Instead it asks the user to specify the coordinate system.

Incidentally, I added UTM support for .shp during a project that had to deal with railway infrastructure vector data.