TransDEM - looking for tips


Active member
I purchased TransDEM a few years ago (and updated to the latest version last week but never got very far with it in the past due to a perceived steep learning curve) but last week I thought I would give it another go after needing some terrain for my fictional routes and am really pleased with the results but being a newbie at this I have a few questions.

Obtaining the terrain data itself was fairly straightforward with the excellent UK 2M LIDAR files from Defra, this gives a really crisp and accurate model that includes man-made structures such as viaducts and road bridges. Trainz has a maximum resolution of 5 M so the output terrain is lower resolution but still very useable (see below). Does anyone know if there is an equivalent source of LIDAR for Scotland and Wales?


Where there are gaps in the LIDAR I have filled in with the lower resolution OS Terrain 50, which still gives a good result for more distant terrain or for areas that are relatively flat.

The more complex part of this is the background map texture and producing the UTM tiles. I've followed the tutorials and exported at least seven versions of my test map and trying to work out what to do with the resulting files.
So, I have been creating 3D UTM tiles with the high resolution (size 18 on the map) aerial photo imagery from Bing but it is a repetitive process capturing all the snippets required to cover a relatively small map even if I draw route lines. The web map tile function is really good though, particularly the historic Ordnance Survey 25 inch and 1:25,000 scale data. What size in TransDEM should be used for this?

The 3D UTM tiles look really good but are clashing with the ground terrain (see below) This is in TANE but I am using TRS22 Plus for my main work. I tried importing one of my earlier test models into 22 and that seemed to be all present and correct apart from the map textures. I will try bulk selecting and raising off the ground in S20 but I am concerned that PBR textures will clash even more with the tiles.



The other confusing thing with this is the difference between the UTM grid and baseboard grid and so I have found an overlap is necessary (adding DEM beyond the area I need) so baseboards are created that UTM tiles can be placed on.

Anyway, I am really excited about the possibilities TransDEM can bring to my route building, it is indeed a great piece of software. I plan to find some small parts of the country that match what I want but are not too obviously recognisable and merge these into my main route, most of which is as flat as a pancake!

My original intention was to export the aerial imagery to ground textures as a guide and then paint it over myself with real textures but not sure what the best workflow is.

Any tips or suggestions are most welcome!

Fantastic thanks Malc!

A test of the a few tiles of the 2M LIDAR for Wales has produced a pretty good map with ground textures and a few UTM tiles. This is really useful for creating moody moors and magnificent mountains to slot into my fictional routes.



I will try the Scottish data you have kindly provided a link to shortly as well.
Great looking DEM Routes shown here........

I bought Dem Route Software from Geophil recently and have to start doing that steep Leaning curve too!

Without practice and the Pre made Dem Routes from various Authors including JRFolco, the DEM Route Software is nothing short of amazing for sure.
Thanks Blue!

I'm experimenting with another TransDEM test project with English 2M LIDAR and still seeing some...I guess you would call it Z-buffering maybe...between the terrain and UTM tiles. Raising the height of each tile in Surveyor (TANE for this test) by 1-2 M helps for most cases except where there is a steep change between elevations such as cliffs. Not sure what to suggest so I will ask over on Geophil's TransDEM forum unless anyone has any ideas?



Can anyone shed any light on this (sorry I couldn't resist)! On the left is a tile at default height 0 and to the right is a tile I have lifted by 1 m

In the meantime I will test merging some terrain I made earlier into a backup of my main route to see how much of a pain that will be. I will also create something with some of the Scottish LIDAR from although coverage of that is much more limited than for England and Wales, mainly just Edinburgh and a few other random spots that may be useful.
Congratulations, Gary on your success! I use TransDEM quite often to create fictional routes and have gone as far as to use a DEM to give me the land and I've put in routes where one could exist while keeping roads and terrain features in place. This is an added challenge, and the results can be quite convincing in the end.

I've never used UTM tiles, but I have used the old basemap objects in the past. The issue is exactly the same without PBR textures. The reason is the terrain has a poorer resolution than the objects and the steps are bigger. The objects, sitting under the surface of the course terrain may be just close enough to the surface but not completely through to cause the z-buffering to occur. As you noticed, adjusting the height of the tile just a smidge will remove the z-buffering which is caused by the video card attempting to render both the terrain and the object in the same place at the same time, which can't be done and causes the flickering or jumping between the two objects.
Which is the best DEM for Trainz baseboards ?

I had DEM from 2 providers :
JAXA japan : as .tif file (DSM), file size approx 54MB.
SRTM3 US NASA : as .hgt file, size approx 25MB.
TransDEM can open both of them.

Which is more accurate topographic in Trainz Surveyor ?
Some said JAXA and other said SRTM

Or there are any providers other than above ?
How is the program and could I pay someone to make me a route for me for cash in hand pretty easy route to mostly flat terrain from Washburn Texas to outside Saginaw Texas on the Bnsf Wichita Falls sub