TransDEM Forum

Hello Roland,
I knew in HOG how to change horizontal and vertical scale of the DEM file before creating the map, that is cheating with reality by downscaling the created map by 2 or 4. This way, length (and boring driving) between stations are shortened, trainz route size is lowered, while still having advantage of a real looking relief and railway network. I do not see such a possibility in TransDEM. Is there some ?
JJ

Horizontal scale: There is no way to cheat. TransDEM makes every effort to obtain correct scale, to enable all kind of different geo data sources to fit together and to retain this information even in the Trainz route, through its static UTM baseboard mapping and the Trainz World Origin object. Manipulating scale would neutralize this effort.

Vertical scale: In reaction to the low quality of first generation ASTER DEMs (2003-2006) I implemented a number of DEM editing functions with the objective to get closer to the real thing. At least one of these functions could also be (mis-)used for the reverse direction: "Raise/Lower Elevation Range".

What I would suggest is to stick to scale wherever possible. If distances between stations become too long, you could shorten them by leaving out a couple of baseboards altogether. You would build your route in modules, merge them where you please, and create fictitious "transition boards" to make the join. If your entire route is on a slope, you can also raise or lower individual Trainz route modules after they have been created, to bridge any vertical gaps.

OK, OK. From my side, I managed to do it, by exporting DEM and saving routes to .xyz format. Then treats the xyz files with Excel to downscale xy data (to be able to use excel, I limited the maps to reasonable size (20 x 10 real kms), which gave me 32000 lines roughly). And it worked. I have not looked after getting the tiles at the reduced scale for the moment being. I do not know if I will use them.
I will make some trials to see if I am pleased with downscaling results. Your suggested method would be another interesting possibility.
As I said, I do not want reality, but realistic fictious routes. But of course, I respect the point of view of strict reality.
JJ