New track system
The way tracks are edited and specially shaped hasn't changed in 3 years. Some new tools have appeared, some new capabilities were added like splitting and boundaries, but it's still the same system implemented back when the game was a prototype and I was focused on releasing with a deadline. It has been long overdue to review this system but it's such a core piece of the game, it had to be done carefully. I spend most of June researching computer curve design to find a new system, and this is the result:
Up until 1.8, railways in the game have always been composed out of circle arcs and line segments. While this produces pleasant results to the eye, in the real world such a railway would only be valid for very slow vehicles like older tram systems. The 1.8 curves have first degree continuity (position), but are second degree discontinuous (curvature).
In 1.9 the new track system is based on the Hobby spline, which is capable of approximating both circle arcs and clothoids, and gives good results when trying to approximate how railways look like. Clothoids are short segments of the Euler spiral and are used in CAD drafting to transition between curvatures, so for example, to link two circle arcs with a straight section in the middle:
The limited track mode emulates the 1.8 behavior, and the full mode allows the spline to express the arc-straight connections with a clothoid-like segment. Players can choose between the two modes. If you don't like the new mode, set the track creation mode to Limited and you will never have to deal with Full mode again. All 1.8 imported games have their non-branch tracks set to Limited mode.
An additional new mode, Point, is also available (but not at creation time). Point tracks behave very differently than limited of full tracks. A Point mode track node is always part of the track, and there is no tangent polygon or arc fitting. Instead the player has direct control of the tangent angle for every point mode track node. Point mode allows to do things like curved dead end tracks. It is also the mode all track branch tips use, since it is capable of linking any point in the map with any possible tangent, unlike the Limited/Full system.
Late train boarding for pax
I always wanted to enable strict pax boarding for trains, so pax only board the exact train in their schedule, a not any train which happens to be on the same line+stop, but this breaks player saves which depend on pax being able to board late trains. So the solution to have both things is to make it official for pax to board (some) late trains, with a specific set of rules.
Basically pax will board late trains if the predicted train arrival is still before the departure time of their next train. If the next stop is the final stop, pax will accept late trains up to 3h.
N-track platforms
A very old limitation of the game has been lifted in 1.9: station platforms can now be composed of any number of tracks, starting at just 1:
Track+point line stops
And to completing the previous new feature, line stops are now always based on a exact point on the track, rather than some general direction on half of the platform. This means players now have full control on where trains stop on platforms on a per line per stop basis.
As always, check the devblogs for more in depth descriptions of these new features:
https://carloscarrasco.com/nimby-rails-may-2023/
https://carloscarrasco.com/nimby-rails-june-2023/
