This page documents some of the migration steps needed when loading MTR 3 custom content in MTR 4.

JS Scripting from the Nemo Transit Expansion is not implemented at the moment. If you rely on contents that make use of such feature, you are advised to either stay on MTR 3.x + Nemo Transit Expansion addon, or explore with the new Resource Pack Creator in MTR 4 and see whether similar effects can be achieved.

In MTR 3, a train refers to a single type of train, which can be dynamically fitted with any amount of carriage length depending on the siding length.

In MTR 4, the concept of a Train no longer exists. Instead we now have carriage (Vehicle car), where player can mixes different carriage together to form a train (consist). (Which, to the surprise of some, is actually how a train is made up in real life!)

• For MTR 4 loading legacy trains made for MTR 3, the MTR mod will try to detect and split your “Train” into several parts (e.g. Cab Forward, Trailer, Cab Backward)
• For the new MTR 4 format, you are suppose to define everything per-carriage instead of a single train.
• While JS scripting is not implemented yet, if and when it is implemented, you are expected to make heavy modification to your script to align with the new per-carriage system.

To reflect the different transport types supported in the MTR mod, train are now referred as vehicle.

• Train which uses a base_train_type but without providing texture_id no longer has base train's texture applied (Only transparent train with bogie & gangway)
• Train which does not specify a valid gangway_connection_id (Or does not have it) can no longer walk between gangways like they can in MTR 3
• When specifying built-in MTR barrier/gangway/vehicle texture, replace textures/entity/* to textures/barrier, textures/gangway and textures/vehicle respectively, as they are now separated.

• Custom Destination's CJK Ratio has been changed in MTR 4
  • Previously, -2.0 means English is bigger than Chinese, 0.0 for equal weight, 2.0 means Chinese is bigger than english
  • In MTR 4, this is changed to represent the scale CJK characters are rendered at:
    • Non-CJK characters always takes up a weight of 1.0
    • For example, assume we have the text English1|中文|English2.
      • If CJK Ratio is 2.5, this would mean English1 has a weight of 100%, 中文 has a weight of 250%, and English2 has a weight of 100%
      • If CJK Ratio is 0.1, this would mean English1 has a weight of 100%, 中文 has a weight of 10%, and English2 has a weight of 100%