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Author Topic: How do I generate tropical forests?  (Read 1963 times)

Jundavr

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How do I generate tropical forests?
« on: May 13, 2021, 11:01:08 pm »

The world is 17x17 in size, and I started resorting to the preset field values.

However, no matter the parameters of the biome (rain, drainage, elevation, temperature) I cannot generate a tropical forest, only temperate broadleaf forests.

I've set the biome temperature to 101, and still no luck. If I set it to something ridiculous like 200 I'll finally get the tropical forest but my dwarves will die soon after I embark.

I've looked everywhere, in the wiki and even some world cookbook threads. Either there's something I'm missing or the world generation is bugged. Any help appreciated.
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Bumber

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Re: How do I generate tropical forests?
« Reply #1 on: May 14, 2021, 02:33:30 am »

According to the wiki, temperature is affected by latitude and elevation. I think that may factor into converting your presets into actual biome temperatures:
Unfortunately, temperature is harder to affect directly in world gen because, according to Toady One, it's affected by both latitude and elevation. Additionally, when the pole setting is none, the tropical or frozen biome variants do not respect the otherwise static divisions.

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PatrikLundell

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Re: How do I generate tropical forests?
« Reply #2 on: May 14, 2021, 03:24:57 am »

Yes, as Bumber said, the "tropicality" is dependent on latitude primarily if there are any poles (no pole => no latitudes). If the location is in the tropical region the biome will become tropical (for those biomes that do have tropical/temperate versions: a glacier will still be a glacier at the equator if the temperature is low enough). A band around the equator is the "maybe" zone where other parameters can influence whether the biome becomes tropical or temperate (temperature and rainfall, if I remember correctly), with different biomes having different criteria and different ranges.

Also, as Bumber mentioned as well, the actual temperature DF generates is modified from the PSV ones based on latitude (if present, of course) and elevation.

Thus, if you want a tropical forest in a 17 tile high PSV world with at least one pole you ought to set forest resulting parameters for the equatorial band to guarantee it. I don't remember if the bands immediately to the sides of the equator are in the definitely tropical or the maybe zone, but in the tropical zone you can get your tropical forest to have any non freezing temperature (below that it would be taiga and then glacier below that).
Also note that a single pole has half as many degrees of latitude per tile than a dual pole one, as the world spans only 90 degrees rather than 180, roughly doubling the size of each band (roughly, because the underlying math is tied to latitudes, not tiles, so the boundaries may not align exactly on tile boundaries).
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Garfunkel

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Re: How do I generate tropical forests?
« Reply #3 on: May 14, 2021, 04:56:50 am »

I vaguely recall reading that some biomes only emerge in the largest world size due to the reasons PatrikLundell explained but I can't find the Wiki article now.
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PatrikLundell

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Re: How do I generate tropical forests?
« Reply #4 on: May 14, 2021, 07:24:50 am »

It's not DIRECTLY related, but dry broadleaf forests can only appear in world that are at least 129 tiles high (you can make them narrower with custom parameters: mine are 33*129) because the code checks for that to be the case (other parameters are quite finicky as well). If it wasn't for that size check it would be possible for them to appear in worlds that weren't as high.
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A_Curious_Cat

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Re: How do I generate tropical forests?
« Reply #5 on: May 14, 2021, 07:08:20 pm »

I always like to embark in tropical rainforests, and (usually) have no problems finding them.  Of course, I always generate the largest size worlds to maximize my chances of finding a good embark (read:  suitable for someone learning the game).  If all else fails, you might want to consider Biome Manipulator.
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orius

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Re: How do I generate tropical forests?
« Reply #6 on: May 15, 2021, 02:00:57 pm »

In addition to temperature, you might want to play around with settings like rainfall too.  Possibly drainage?  Rain alone might generate more swamp than forests.  And of course up the forest square and region counts too.  You don't need things to just be hot for jungles, you need humid environments too, and that means more water.  Otherwise, you'll probably get deserts instead. 
« Last Edit: May 15, 2021, 02:03:50 pm by orius »
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A_Curious_Cat

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Re: How do I generate tropical forests?
« Reply #7 on: May 15, 2021, 09:16:58 pm »

Pay attention to this chart.  It shows the relationship between rainfall, drainage, and the biomes they create.
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Jundavr

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Re: How do I generate tropical forests?
« Reply #8 on: May 17, 2021, 05:43:31 am »

Thanks for the help everyone. I was generating a world without poles. Adding a pole finally allowed me to get tropical biomes.
« Last Edit: May 17, 2021, 05:48:17 am by Jundavr »
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PatrikLundell

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Re: How do I generate tropical forests?
« Reply #9 on: May 17, 2021, 07:14:18 am »

Without poles it's all dependent on temperature.
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