In the picture below


I do not understand which game concepts nodes on your graph represent so i wont answer anything about it. I can only tell you that trains pathfinder is finding a path within a directed graph regardless of rails being bidirectional because there are separate nodes for ...

boskid wrote: Sat Apr 11, 2026 2:57 pm - A_east -> B_east
- A_east -> C_east
- B_west -> A_west
- C_west -> A_west

Is this derived on the fly or are these relations stored and then constructed during pathfinding? Or is the relation always east -> east and west -> west are allowed?

This situation does not create problems because pathfinder nodes are directional.

If railroads are modeled directionally, how are terminal loops possible in Factorio? In the picture below, there's no way to move from B to C over Z without chaning direcitons . Are you 100 % sure is a directed ...

First if all, to
It doesn't. Trains cannot drive backwards so if you do not provide a way to turn around they cannot path to what lies behind them.
Sure, but I'm curious how the calculation works as driving backwards is already some sort of state and graphs with state are difficult. Especially ...

I'm always curious how things work behind the scences and I understand that you might not be allowed to discuss implementation details like this publicly.

04-11-2026, 02-10-27.png

I took a screenshot from one of your blog posts about trains and labled what I consider vertexes (correct me if I ...