Hi Rudi,
my experience is: DEM generation is only dependent on the terrain files in your route, whether they are modified by you or not, whether the resolution of the hgt or aster source is high resolution or not. All works.
They essential two keys are:
1. Create an extra empty freeroam scenario located at the origin of the route and don't move after it has loaded. Just press the "create distant terrain" button.
2. Winter
If you want to have distant terrain in winter all texture files must have the right naming scheme for winter. Negative examples are "Canadian Passes" by JL (no winter at all in the distant) and Soldier Summit (lots of textures get blacked out).
Even some of the Kuju textures are named in the wrong way.
The right scheme for wang tiles compatible for distant terrain is:
Mud000_Wi_A.TgPcDx
Mud000_Wi_B.TgPcDx
Mud000_Wi_C.TgPcDx
and so on,
NOT the "Wi"-part after A,B,C ...
and they have to be located in the same folder like the tiles for other seasons.
Done by me :
https://rail-sim.de/forum/wsif/index.ph ... -Terrain-für-SBB1-Pfäffikon-Landquart-v-1-0/#images
Kris