Convoys' offset shift while reversing

[Phystam]

I am creating a train addon for Simutrans-Extended and checking the offset.
However, the offset will immediately shift and derail while reversing, so I am confused to determine the offset.
Is this a bug? / in the specifications?

[Rollmaterial]

Which pakset are you making an add-on to?

[Phystam]

I'd like to add Japanese trains for pak128.Britain-ex.
This issue is also seen in the original pak128.britain-ex pakset.

[DrSuperGood]

shift and derail

I am a bit confused as to the problem. Simutrans and Simutrans Extended do not have accident/crash simulation so trains cannot derail. If a train does seem to derail, in that it visually appears off rail ways, then that is a bug.

[jamespetts]

Thank you for the report - sorry that you are having trouble. The offset system is, so far as I am aware, identical in Extended to Standard, save that Standard does not have a reversing system.

By "derail", do you mean that the rail vehicles become misaligned from the rails somehow?

I generally find that the best way of producing rail vehicles is aligning them using automatic rendering from Blender so that no offsets are needed for them (offsets are used for road vehicles, however, on account of their needing a different sort of alignment, and also for large aircraft on account of their needing to use pak sizes greater than 128).

If what you would like to do ultimately is fork Pak128.Britain-Ex to produce a Japanese pakset (and this was how Pak128.Britain was created in the first place - it all started circa 2006 with a British trains addon for Pak128), then, unless you need to change the graphics style, you will probably find that you can save a lot of work in the long-term by using the same rendering settings and workflow (and probably also scale) as Pak128.Britain, as you can then use all of the Pak128.Britain objects and have them look consistent with the Japanese objects that you (and possibly others) may add over time (and some things from Pak128.Britain, such as natural features, aircraft and ships, might remain the same over the long term in any event). This may not apply if you are going for a different graphical style to Pak128.Britain, but this would then require a much greater investment of time before it begins to look consistent.

It would be a splendid thing to have a Japanese pakset for Simutrans-Extended, incidentally - I know that Simutrans (and, I think, transport generally) is very popular in Japan (I have seen quite a few Simutrans related videos on the internet from Japan), so it would be wonderful to have Japanese specific content.

[Phystam]

Sorry for my late post.

( How can I insert an image? )
This is the issue.
Fig.1 shows "before reversing", there is a tram train on the rail.
Fig.2 shows "after reversing", this convoy goes out of rail.

[jamespetts]

Ahh, you are referring to overshooting at the end on reversing? This is a long-standing problem to which, despite much effort, it has not been possible to find a solution so far.