TransDEM Forum
https://forum.transdem.de/

Big route problem
https://forum.transdem.de/viewtopic.php?f=7&t=606		 Page 1 of 1
Author:  BtGio99 [ 04 Jun 2021 09:54 ]
Post subject:  Big route problem
Hello, I have successfully created a 20km route, it works fine, and it is completed. TransDEM is just awesome! But now I'd like to create a bigger route, perhaps 1000km :shock: :lol: It's a high speed line, and I wouldn't mind to put a lot of details around it, but after I exported it (cutting the dem where is not necessary) the size is about 1.58GB (without raster maps). Now the question arise: how am I supposed to export UTMs? I thought about splitting the route in several parts, maybe of 200MB each, and slowly merging them in Trainz, however, how can I do that quite accurately? I know transDEM has limitations during the export process, but I mainly bought it for long routes.. Usually I set 17x tiles near tracks (one baseboard) and the outer part about 15x or 14x (two baseboard maximum). Any suggestions? I tried to read the manuals and some topics here, but they weren't much of a use. Thanks! :D
Author:  geophil [ 04 Jun 2021 13:28 ]
Post subject:  Re: Big route problem
Typically, the limitation is Trainz, not TransDEM. But an approach with smaller modules should work, at least for moderate size routes. Nonetheless, I don't think anybody has managed to create a 1000km route. And for each module, a module size of 50km, particularly with a large lateral extent, is more than enough. In mountainous terrain you need sufficient width of the route to make it look realistic in Trainz. I tried this once with the Italian side of the Brenner line, from summit to Bolzano/Bozen, to test the hi-res DEM. It had 15 baseboards across to each side, 10 km. You need lots of main memory to accommodate the amount of data such route module devours.

With UTM tiles, keep in mind that they have to be managed by Trainz as well. You can create up to 999 UTM tiles per invocation in TransDEM, with a route filter active. But think about those thousands of UTM tiles in Surveyor.

For merging the route modules keep track of the module borders and their UTM coordinates. The Trainz baseboard raster created by TransDEM is statically mapped to the UTM coordinate grid. That means as long as you use the same DEM data source and stay within the same UTM zone, merging of modules with adjacent coordinates will be seamless, one of the TransDEM core features since its first version.

North/south routes are most likely to have all their modules in the same UTM zone, but for east/west routes that's different. Before you design a long east/west route, check whether a second UTM zone will be involved. The UTM zone with the majority of the route should become the primary zone. For the secondary UTM zone, transform all georeferenced data to the primary zone. TransDEM has built-in functionality for that.
Page 1 of 1 All times are UTC + 1 hour
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/