Sprawl

[Brambo]

Since 8.0, cities, factories and fields have started to grow out of control, at least when compared to previous versions. I saw this was discussed elsewhere already, but I didn't quite understand whether this is WaD or a bug/balancing problem. I also understand that it has something to do with pak128.Britain (I use 1.07 standard) lacking high-density buildings for some years, but this can't be the whole story. James, maybe you could enlighten me?

Personally, I think growth is way too fast now, and cities after map generation are too spread out. IMHO, this is the one single flaw that makes 8.1 not fun to play.

Thanks!

[jamespetts]

Brambo,

thank you for your feedback. Can you be a little more specific? I.e., is your problem sprawl in the conventional sense of large areas of low-density development in towns, or is it the size of towns per se, or is the rate at which towns grow (at any density), or some combination of the above? In what era are you playing?

One thing that might make a difference to your issue in respect of towns (which will not affect industries) is the "rennovation_percentage" setting in cityrules.tab. The next version of Pak128.Britain-Ex (yet to be released) will use the value 33 instead of 12, which is more suitable for 8.0. I suggest that you change this setting in your cityrules.tab file - this will affect only new games created after the change, however.

As to industries, there was a bug in Simutrans-Experimental 8.0 that would cause excess industries to be generated before any power stations become available, but that was fixed in 8.1. Are you using 8.1?

[Banksie_82]

I too have found this problem. Playing a recent Sumatrans Nightly version (not sure exactly which one, downloaded the same time as Ex 8.0) with Ex. 8.0 and Pak 128.

I find that when generating a new map the cities are, as Brambo says, very spread out. The population is fine, but there is a lot of suburbia and very little city centre. I.e. lots of low level buildings and not many higher level ones.

I didn't play the game for long enough to notice any difference with the town growth.

I did manage to fix the problem, which is why I didn't play it for long. In the cityrules.tab, I changed a parameter (rennovation_percentage) to 75%. I think it was on 40% before I played with it.

It makes the cities look like they did from when I was playing Ex. 7.3, the way I prefer it.

Sorry my explanation is so vague; I don't have Simutrans installed on my computer at work, so I'm going off memory.

[Brambo]

Hi James,

Thanks for your reply. I'm using 8.1 now, and play with timeline off atm, so that power station bug should have no effect anyway. I'd say the town growth is a combination: growth is much faster than in 7.3 in terms of population increase, and this growth is manifesting in low-density buildings. This is not necessarily bad, but now, it's just too fast.

Regarding low-density sprawl in map generation, I have found that selecting "hilly landscape" reduces it, because the lack of flat space forces the building of higher-density housing.

I tried your tip and changed the renovation percentage. Changing it from 12 to 33 changed little, but upping it to the 75 that Banksie_82 used, the cities look just like they did in 7.3 again. I wonder why standard and experimental have such different results? Does the renovation percentage also influence new houses built during game time? I'll play with this setting for a while and let you know what it does to population growth etc.

Meanwhile, is there anything I can do about the field sprawl issue? All farms, even ones not served by my transport company, grow out of control and take up space I wanted to use for railway lines! Stupid farmers, the nerve! Anyway, this is very annoying and I'd love a fix for this.

Brambo,

thank you for your feedback. Can you be a little more specific? I.e., is your problem sprawl in the conventional sense of large areas of low-density development in towns, or is it the size of towns per se, or is the rate at which towns grow (at any density), or some combination of the above? In what era are you playing?

One thing that might make a difference to your issue in respect of towns (which will not affect industries) is the "rennovation_percentage" setting in cityrules.tab. The next version of Pak128.Britain-Ex (yet to be released) will use the value 33 instead of 12, which is more suitable for 8.0. I suggest that you change this setting in your cityrules.tab file - this will affect only new games created after the change, however.

As to industries, there was a bug in Simutrans-Experimental 8.0 that would cause excess industries to be generated before any power stations become available, but that was fixed in 8.1. Are you using 8.1?

[knightly]

I wonder why standard and experimental have such different results?

James incorporated a patch written by me months ago into EXP, but that patch (1) is a work-in-process (2) has known bugs (3) only focuses on better enforcement of renovation percentage. Although I had a newer version of the patch (which I have lost), I did not release it due to performance issues.

Standard does not incorporate that broken patch, thus does not exhibit the monstrous sprawling and lack of city centre problems.

Does the renovation percentage also influence new houses built during game time?

Yes. The same city rules are used in initial city construction and later city expansion.

[Brambo]

Thanks for clearing this up, Knightly. Meanwhile, I have done some testing with farm fields, but for some reason, now no single setup I have tried actually generates any farms! I only get power stations & oil fields etc. What could be the cause of that?

[knightly]

Meanwhile, I have done some testing with farm fields, but for some reason, now no single setup I have tried actually generates any farms! I only get power stations & oil fields etc. What could be the cause of that?

Do you mean, you do not have farms, or you have farms without fields? For the former case, you will have to ask James; for the second case, maybe you can try downloading the latest version of Pak128.Britain at the nightly page, as some time ago, newly generated paksets do not have fields -- but it's fixed now.

[Brambo]

I get no farms, actually, I think I only got power stations, coal mines and oil fields.
In 7.3 this did not occur.

Do you mean, you do not have farms, or you have farms without fields? For the former case, you will have to ask James; for the second case, maybe you can try downloading the latest version of Pak128.Britain at the nightly page, as some time ago, newly generated paksets do not have fields -- but it's fixed now.

[jamespetts]

There are a number of separate issues here, which I shall address separately.

Towns and building density

Knightly is too harsh on himself when he says that his patch is broken; I have not found any problems with it. The original code (and the code that still persists in Simutrans-Standard) contained a significant bug which meant that buildings were far more likely to be replaced with higher density buildings (either during natural growth or iteratively when towns were first built) than they should be according to the "renovation_percentage" setting. In other words, towns were far too concentrated: tiny connurbations with fewer than 1,000 citizens often had quite large buildings and not much else. That is not how towns work in reality: they will sooner grow out than up, and will usually only grow up when there is no more room to grow out, or there is already excessive sprawl. Knightly's patch fixed that, but at the cost of slightly slower map generation. The decision was taken for Simutrans-Standard that the performance difference was a reason for not incorporating Kinghtly's patch at all. After testing it, I found that, although map generation was slower, it was within acceptable bounds, and since a player needs only to generate a map once for many weeks or even months of playing, it was a price worth paying for more realistic cities. In case players of Simutrans-Experimental disagreed with me, I provided the option to disable the new system with the "quick_city_growth" option in simuconf.tab: set quick_city_growth=1 to revert to Simutrans-Standard's system.

The effect is that towns will be less concentrated than in Simutrans-Standard. Using the same (low) renovation_percentage as in Simutrans-Standard (the default, I think, is 12) will result in excessive sprawl. The next version of Pak128.Britain-Ex will include a revised cityrules.tab with a revised figure of 33. Even with the revised figure, cities will be less dense than in previous versions, and this is intentional: the density in Simutrans-Standard is too high. There will be far more interesting suburban passenger transport if town densities are more realistic.

If anyone really prefers the excessive density of Simutrans-Standard, either set the renovation_percentage setting in cityrules.tab to a very high level (as other in this thread have already tried), or set quick_city_growth=1 in simuconf.tab.

Knightly - what are the bugs of which you are aware in this? It's rather a pity that you lost the latest version of your patch. You are quite welcome, of course, to push a fix to your Github repository, where I'll gladly incorporate it into the next release of Experimental :-)

Town population growth

Brambo, I have not had any other reports of this issue and not noticed it myself - can you elaborate on your observations that town population growth in Simutrans-Experimental 8.1 is higher than in 7.3? If you find the growth too high, however, you can adjust simuconf.tab settings for this, too:

Code Select Expand


growthfactor_villages = 400
growthfactor_cities = 200
growthfactor_capitals = 100


is the default: doubling the various numbers should halve city growth rates (and so forth). The next release of Pak128.Britain-Ex will feature higher growthfactor numbers, and therefore lower town growth.

Fields

I have isolated this to a bug that can be reproduced in Simutrans-Standard: see the bug report here. When a fix is released for Standard, I shall incorporate it into Experimental and expedite the release of the fix.

In the meantime, however, note that fields can be built over without changing to public player, except when a farm has the minimum number of fields already. Just as in real life, fields (in both -Standard and -Experimental) are dispensable to some degree. Note that you can also build power lines over fields without even destroying the field - just as in real life.

Absence of farms

You will get only power station related industries if you have a large number of large towns, start late in the game, set "electricity_percentage" in the new world dialogue to a high level and have few industry chains. This is because Simutrans will make sure that there are enough power stations (and associated support industries) to cover the whole population (or whatever fraction is selected in "electricity_percent"): if few industry chains are selected in comparison to the population, there will only be room for power stations. I suspect that this is what is happening here.

[Brambo]

James, many thanks for you extensive answer! I'll keep on trying some more settings and let you know whether I come across any problems.

[Brambo]

Hi James,

Just tried 8.2 and the fields bug is still present. I though prissi said he had fixed it in the other thread, or has he not? I'd love to have this bug fixed if possible, because all those fields annoy me to no end. :(

thanks!

[jamespetts]

Brambo,

the fields bug was fixed by Prissi, which I incorporated into the "-devel" branch on Github. The "-devel" branch contains a large number of as yet immature GUI changes, and is not ready for release. Version 8.2 comes from the more stable 8.x branch.

Until the field fix is incorporated into a release version, however, please be aware that you can build over fields.

[Brambo]

Ah, I see, thanks for the reply!

[jamespetts]

You're welcome. Happy playing!

[Dutchman on Rails]

I noticed the same effect on the fast-growing cities, and spotted what happened.

When a building is added to a city, this triggers an increase in population. The extra buildings therefore have a feedback on extra population growth.