Poor Pathfinding

[Jan]

the first of which was Transport Tycoon, released through Microprose in 1994

Quote from Chris site..........are you his son or Chris himself if you got the game in 1993?

Back to thread, I never had train or automobile lost in T&TT unless I made a mistake. My bus is running every direction for couple minutes in LoMo.

[The Irish]

I agree, Pathfinding is very poor indeed.

And sometimes it is really hard to make a route that actually works, even with waypoints.

Another thing I noticed is that if a vehicle is broken down, but keeps dragging along, it skips the waypoints and just takes the next real destination which means it get's lost again.

[Davie_UCF]

One thing thats annoying me that i can't figure out is that trains sometimes won't turn around at the station.. they'l keep going forward until they have to end up going back the way they came...

Why do they do that? Its simpleenough to just turn around at the station and head back!

Davie

[Realgar]

One thing thats annoying me that i can't figure out is that trains sometimes won't turn around at the station.. they'l keep going forward until they have to end up going back the way they came...

Why do they do that? Its simpleenough to just turn around at the station and head back!

Davie

I actually prefer when they don't turn at stations, cause otherwise they'd face the trains coming behind them on my layouts =)

Code: Select all

  ----     <-   tracks

         /LOAD STATION-------------DELIVER STATION--\
         \------------------------------------------/

hope you got the picture, im bad on ASCII draws =P


but pathfinding IS bad, I made a track, later on with more money decided to improve it, and while I was building the new one the trains would enter the new track even though that would take them nowhere =P

[Faithful]

Has anyone forwarded this problem to those that might have the power to do something about it? Not sure who that would be myself.

[Carskick]

Has anyone forwarded this problem to those that might have the power to do something about it? Not sure who that would be myself.

If I knew where to send it, I would. Both CS's site and Atari's locomotion site offer no information about where to send suggestions, ideas, etc.

No, I am not related to Chris in any way. If I was, I'd call him and say "Uncle Chris, FIX DA BUGS. Thank you." I was only 5 or 6 years old when I started playing TT, and it was when it first came out that we got it. I can't remember if it was 93' or 94', but if the game was released in 94', I guess that's when I've been playing it since. I'll change my profile.

[n0brain]

Trains (or other vehicles...) sometimes turn around at the stations and other times it doesn't...

here are some hints... (based on observation)


Trains seem to have very basic pathfinding AI's. So when they reach a destination and stop, they'll turn to the general direction of next destination.

So, if the next stop is the other way, then it'll turn around.
If not, they won't.

To assist this basic pathfinding AI, you should consider,

a. using one-way signal at the entrance of the platform
(quite simple, but not possible with multiple platform station where two-way signal is preffered.)

b. using waypoints.

c. build the network so that AI can find it's way.
(I mean... if you design the ro-ro station, make them roll-in to the station from the behind, and exit from the front-side...)

example...


/-STATION-\
|--STATION-|----------------------------- <-
|--STATION-| /------------------------- -> destination
|--STATION-/ |
\----------------/
if you build station like this, trains wil try to turn back, at the station, because they think it's the shortest route. (it's shortest in fact, but not good)


/-STATION-\
|--STATION-|---------------------------- -> destination
|--STATION-| /------------------------- <-
|--STATION-/ |
\----------------/

in this case, they will just go fine. without any waypoints...


I think the AI is just find the way it is... because IMHO anymore than basic pathfinding, the game will be very sluggish after some 50th train or so.... (even only with basic pathfinding, it begins to suffer a little after you/and your competitors get hundreds or more trains...)[code][/code]

[Severn]

When a game is made with its main focus being, "getting cargo from point A to point B", you should expect some mighty fine pathfinding.

Waypoints might help, but they shouldn't be needed.

I could not agree more. Even the early scenarios require some complex "supply chains" to win them and quite a few vehicles, so having to worry about the minutest detail of "how" the vehicles should go from A to B is irritating and takes too much time.

It's bad enough for trains, but in cities where your waypoints could end up in the middle of an apartment block as the city grows, it's not acceptable.

[Severn]

I think the AI is just find the way it is... because IMHO anymore than basic pathfinding, the game will be very sluggish after some 50th train or so....

But the pathfinding isn't poor, it's broken. In this very simple example the game just could not find a route from A to C without placing a waypoint. It found C to A fine, but not A to C.

Code: Select all

                 +-->--+
Station AX--->---+-->--"--XStation B                  
Station AX---<--+---<--"--XStation B
                |      |
                |      +->XStation C
                +----<----XStation C

(The " is a bridge, the X is junction at the stations to allow platform switching by arriving and departing trains. The > and < show the only possible directions of travel, controlled by one-way signals.)
I posted a screenshot of this at http://www.tt-forums.net/viewtopic.php?t=10178

[siu238X]

I think the AI is just find the way it is... because IMHO anymore than basic pathfinding, the game will be very sluggish after some 50th train or so....

But the pathfinding isn't poor, it's broken. In this very simple example the game just could not find a route from A to C without placing a waypoint. It found C to A fine, but not A to C.

Code: Select all

                 +-->--+
Station AX--->---+-->--"--XStation B                  
Station AX---<--+---<--"--XStation B
                |      |
                |      +->XStation C
                +----<----XStation C

(The " is a bridge, the X is junction at the stations to allow platform switching by arriving and departing trains. The > and < show the only possible directions of travel, controlled by one-way signals.)
I posted a screenshot of this at http://www.tt-forums.net/viewtopic.php?t=10178

I'd have a suggestion that is,

"If the ideal route is going to the right, let it be."

Though I still have broken paths on this occassion, it actually have smaller chance I must say.