Factorio Forums

If we want to be even more exact, I don't believe OpenTTD has an equivalent - the Factorio Chain Signal is kind of a cross between a combo signal and a path based signal.

My understanding is that the color of the chain signal usually depends on the state of the signals ahead of it (green = all exits available, blue = some exits available, red = no exits available) and so far so good, that's like the combo signal (except green and blue are rolled into just green). But a Chain Signal doesn't actually permit or block a train to pass based on its green/red/blue state. Instead when a train reaches a chain signal it asks the chain signal to reserve a path for it, if successful then the chain signal (and all chain signals in the reserved path) turns yellow and the train can pass. (this is different than the OpenTTD PBS which reserves pieces of rail, the chain signal reserves whole blocks)

Correct me if I'm wrong, but the only signal kind in OpenTTD that takes a train's wishes into consideration is the Path Based Signal, the other signal kinds are all purely mechanical based on the state of other signals and don't give a shit about what the train wants. OpenTTD presignals let a train through even if the open exit is not the exit the train wants to take, this can be weaponized to for example redirect trains into a holding buffer until the platform they want to stop at is free. A Factorio Chain signal will only let a train through if the train can take the path it wants to.

As most people are hitting on here, they're very different games and the way the games are designed reflects this.

The most obvious point in TTD is that you are not a little dude running around, and detail at high level zooms is really not a factor.

Though the second most salient point is that the trains in factorio are a feature, they're freakin awesome, but they're a feature of the base game, they are not a core mechanic, and the implementation reflects this.

TTD has vehicles at its core, they are the base mechanic, transporting goods is the bedrock of the game, and doing so on a massive scale is one of the critical goals the player is expected to strive for and be able to achieve. This means that the logic used must be more simple, robust and reliable to ensure good gameplay, in the same way that the construction and item handling in factorio is. The pathing logic that factorio uses, which appears to chunk track segments together and update by request of the trains, is not computationally optimal for large throughput, and will result in many incredibly irritating problems for the player, as many people in this thread have pointed out, if that was the focus of the game in factorio.


TLDR: You're making a category mistake by comparing trains in factorio to trains in TTD, a more apt comparaison would be inserters in factorio with trains in TTD.


Also path signals are often the lazy man's signal, which I don't think were actually in the original game, you don't ever need to use them. The functionality they offer over regular signals is very specific and unless you're being lazy you'd only use them in particular areas.

Ripshaft wrote:Also path signals are often the lazy man's signal, which I don't think were actually in the original game, you don't ever need to use them. The functionality they offer over regular signals is very specific and unless you're being lazy you'd only use them in particular areas.

The original games (Transport Tycoon and Transport Tycoon Deluxe) only had regular block signals; TTDPatch added the pre-signals, and OpenTTD added the path signals.

TruePikachu wrote: The original games (Transport Tycoon and Transport Tycoon Deluxe) only had regular block signals; TTDPatch added the pre-signals, and OpenTTD added the path signals.

Actually I believe TTDPatch added path signals first, it's completely insane they managed to hack a feature like that into the game (although the implementation of PBS wasn't as solid as OpenTTD's eventual implementation)

TruePikachu wrote: The original games (Transport Tycoon and Transport Tycoon Deluxe) only had regular block signals; TTDPatch added the pre-signals, and OpenTTD added the path signals.

Ah good so I wasn't just imagining that =p

Also just wanted to clarify - I freakin love the trains in Factorio and heavily use them in my games, and I fully agree with the original author that the way the signals update in advance in Factorio is a wonderful feature that I appreciate in part because of how nice it is compared to my memory of TTD and open TTD.

My point is only that this in no way reflect poorly on TTD, it has a different focus, and its design reflect this. Judge each game on it's own merits and not the merits you might expect it to have, and you'll find both are excellent destroyers of your time that you will not regret.