Modding Changes 1.20


  • Some new models utilizing the "fr" suffix or prefix are still work in progress and it is likely that they might change significantly in some next patch. For this reason it is recommended that you avoid using them in your mods at this time.
  • When basing you model on the original ones, add to your mod also ALL original /automat/ files used by it. The names of the files are generated as SHA1 hash of theirs content so whenever we change the parameters of the material in any way, a different file will be used to store them and the original file might cease to exist if there is no other model utilizing the original parameters.
  • When modifying original models, always include ALL compoments of the model (pmg+pmd) instead of just those you changed. Otherwise you risk crash if we change the model.
  • As always when adding new objects to files which support multi-file approach (e.g. road_look.sii) it is HIGHLY RECOMMENDED to use suffix or prefix in the name to avoid conflicts with new objects we are adding in patches. Otherwise you might have to use the batch renaming functionality (see Batch renaming) to fix the conflicts when new patch appears.

Misc useful commands

  • Running the game with -unlimitedlog command line parameter will disable the standard 1MB limit on size of game log file. This might be useful during update if you want to focus on some bugs first.
  • Running the game with -validate command line parameter or executing validate command on the console will run special game mode which will load all defined models, prefabs, vehicles and other objects to detect missing textures and similar errors. By examining the game log you can determine what the game was trying to do when error appeared. Note that there is still lot of things which might be wrong which are not checked in this mode.
  • Running the game with -error_overlay command line parameter will show overlay with number of error and warning messages printed to the log once at least one such message is printed.

How to convert map

  • Ensure that the log contains no errors related to vegetation profiles. Load of the map in old format will bake most of that information into the map file so it is critical that the information is correct before continuing with the conversion.
  • Use the replacement dialog (F3, "Prefab node correction") to add new prefab nodes which we added to some ferry prefabs in Scandinavia.
  • Save map
  • Do rebuild (F8)
  • Save map


Traffic-related changes

AI vehicle type definition

To specify spawned trailer count per vehicle, use the array attribute spawn_trailer_count. It defines the array of possible trailer counts for gived vehicle type. Before each AI vehicle is spawned, the game randomly selects one of the value from the array. So far, only values 0 and 1 are supported. For example:

# Set the trailer spawn probability to 75%:
					spawn_trailer_count[]: 0
					spawn_trailer_count[]: 1
					spawn_trailer_count[]: 1
					spawn_trailer_count[]: 1

Currently, the default trailer spawn probability for trucks is 90%.

AI vehicle definition

To allow better control over AI trailer spawning, the meaning of attribute attachable_trailer has been modified:

BEFORE - when choosing a trailer model to spawn, the game randomly selects one, which name matches ANY OF THE STRINGS contained in the array

NOW - when choosing a trailer model to spawn, the game randomly selects ONE OF THE STRINGS contained in the array and then selects a model which name matches the selected string. This allows specifying spawn probability for specific trailer models. Furthermore, this attribute supports wildcard '*' - it can be placed at the beginning of any string, at the end of any string or both (beginning and end) to allow partial trailer name matches.

To allow all trailer models, use attachable_trailer[]: "" or attachable_trailer[]: "*"

Spawned trailer count can be set also per-vehicle by using attribute trailer_count. It works the same way as spawn_trailer_count defined per-vehicle-type

AI trailer definition

It is now possible to specify, to which AI vehicles can each AI trailer be attached - using array attribute allowed_tractor. This attribute supports wildcard '*' - it can be placed at the beginning of any string, at the end of any string or both (beginning and end) to allow partial name matches. For example:

# Allow this trailer be attached only to a single vehicle
					allowed_tractor[]: "traffic.scania_r_a"

By default, all vehicles are allowed.

Vegetation profiles

Most of the information previously stored in vegetation profiles, except for the list of models, is now stored per-item inside map to allow for easy local tweaks. Note that when converting from older map format, the editor will extract that information from vegetation profile and store it inside the map. From that moment the corresponding information inside the vegetation profile is ignored and only the list of models is used.

Note that because of changes in the accuracy of the stored values, some objects might slightly move as result.

Environment & skyboxes

Sun profiles (climate/default/nice.sii, bad.sii) are not bound to time anymore, rather to sun position. Thus low_elevation and high_elevation define interval when the profile is used. Meaningfull range is -90 to 90 degrees, with 5 degree step. It works same as before, during given interval sun profile is present alone, outside of the interval it starts to blend with its neighbour. The only complication is sun_direction, that is used for splitting morning and afternoon profiles for same elevation (+1 = rising sun / morning; -1 = falling sun / afternoon; 0 = use profile for both).

Sun position is computed from actual time and truck position. Conversion formula from map coordinates to earth coordinates (namely latitude) is in climate profiles (climate.sii) as latitude_a and latitude_b values, so its possible to make differently positioned earth zones on single map just by chosing different climate profile. Some additoinal data are in environment data (env_data.sii) - day_in_year (172 = summer solstice), summer_time (+1h).