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Author Topic: Coming over from the Simcity four community at www.simtropolis.com  (Read 1923 times)

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mightygoose

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Holy sugar guys,

 this is an impressive feat, the transit modding community for sc4 are very much interested in your implementation of the A* search algorythm in your pathfinding... but congrats on an awesome game.

yours

John

Offline jamespetts gb

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Re: Coming over from the Simcity four community at www.simtropolis.com
« Reply #1 on: April 30, 2009, 09:43:10 PM »
Welcome! I am glad that you and others at Simtropolis find this simulation interesting! Doesn't SC4 use A* already, though? And there are two separate pathfinding algorithm implementations in Simutrans - (1) for finding routes for vehicles on the map (which uses A*), and (2) for finding passengers' and goods' routes between stations/stops. That does not use A*, but a "beam search", which finds the (or rather, a) route with the fewest changes. However, in my Simutrans-Experimental branch, I have replaced the beam search with Dijekstra's Algorithm to implement more functionality. Which of the two were you particularly interested in? :-)

mightygoose

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Re: Coming over from the Simcity four community at www.simtropolis.com
« Reply #2 on: April 30, 2009, 10:56:50 PM »
yes it does already use it but we have found ways of editing the parameters of the algorithm and we are trying to optimise pathfinding efficiency against memory usage and in game lag. up until now its mainly been trial and error. also we are trying to emulate realism by adjusting the transportation mode affinities, ie promoting walking more, increasing max allowable travel distance and network speed/interchange cost.

Offline jamespetts gb

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Re: Coming over from the Simcity four community at www.simtropolis.com
« Reply #3 on: April 30, 2009, 11:05:46 PM »
Ahh, very interesting! I remember years ago downloading the Network Addon Mod and using the "better" pathfinding. I didn't realise that it was still being improved! It's much harder, of course, when you're adjusting parameters than when you are able to fiddle with the source code ;-)

Blue Lightning

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Re: Coming over from the Simcity four community at www.simtropolis.com
« Reply #4 on: April 30, 2009, 11:12:18 PM »
Well, now, we have better understanding of the traffic simulator and its properties, and so far I say sim Z is the best. I am a member of the NAM Team (Got on last month or so) and pretty much now, sims are commuting more realisticly. However, we have found that the "better pathfinding", "perfect pathfinding", and "2,5,10x Capacity" sims are actually not good for the main simulator.

Vince

EDIT: Also, due to EA's EULA, we can't edit the Source Code and distribute it, sadly.

mightygoose

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Re: Coming over from the Simcity four community at www.simtropolis.com
« Reply #5 on: April 30, 2009, 11:18:35 PM »
cor better pathfinding hasnt been used for years, as of march 2009 we have three A, B and Z each with easy medium and hard levels of network capacities...

Find some of the latest work on our simultor tweaking in this thread [linkie]

you may have to register on that site to view it.