[MC-129767] Dungeons not generating at same positions anymore

WAI reason

I've chatted with Prof, it's an unfortunate change due to the updating of the world gen code that's considered "Working as intended". Sorry! 😞

– @unknown in this Reddit comment

The bug

Dungeons are not generating anymore at the positions where they used to generate in previous versions with the same seed.

In general it looks like less dungeons are generating.

Examples

Older version	Newer version
[media]	[media]
[media]	[media]
[media]	[media]

Seed	Position	Version dungeon existed	Version dungeon was missing
7015474738862924540	`/execute in overworld run tp @s 424.78 41.00 -466.80 -176.19 24.85`	18w09a	18w10d

The bug

Dungeons are not generating anymore at the positions where they used to generate in previous versions with the same seed.

In general it looks like less dungeons are generating.

Examples

Older version	Newer version
[media]	[media]
[media]	[media]
[media]	[media]

Seed	Position	Version dungeon existed	Version dungeon was missing
7015474738862924540	`/execute in overworld run tp @s 424.78 41.00 -466.80 -176.19 24.85`	18w09a	18w10d

Linked issues

is duplicated by 1

MC-135524 Dungeons are not generating at all. Resolved

relates to 1

MC-131462 Coordinate math error causes structure not to generate and possibly other issues Resolved

Attachments

Comments 22

kumasasa 2018-05-17T06:16:19Z

Seed and Coordinates ?

Nick Sloan 2018-05-24T12:03:38Z

Here is a seed: 7015474738862924540

And here are the coordinates: /execute in overworld run tp @s 424.78 41.00 -466.80 -176.19 24.85

You will notice that somewhere between 18w09a and 18w10d, the dungeon at that position (in 18w09a) stops generating. In general dungeons seem a bit more rare in the later snapshots than they were previously.

There are other changes in generation as well. In 18w19a you can go to those coordinates, turn around and follow the cave a few blocks to find a lava source that is not there in any previous snapshots. Follow it a bit further until you reach a larger opening and you'll see that a lava source is missing in 18w19a that is there in all previous snapshots. This kind of variation might be expected though.

Lantien 2018-05-24T19:51:15Z

the seed is -702071384745498

on the same map I find a double spwner which is no longer there and even a dungeon without chest.
I also remark that the jonjon are very very rare under water, but I suppose that it is for evie that the dolphin guides us. for cordonnates go see a screen.

double spawner -100 30 -80

no chest -144 40 -28

one spawner 223 25 108

marcono1234 2018-06-04T23:27:41Z

I changed the summary and the description of the report. I hope you are fine with these changes and it still describes the bug you were experiencing well enough.

Lantien 2018-06-05T08:34:43Z

thank you . I'm not very good at English (I speak french)

12 more comments

Matt 2018-06-06T09:11:37Z

In 1.13-pre1 dungeons are in different places but their quantity is ok, there's a lot of them.

kumasasa 2018-06-06T15:54:41Z

@unknown: What's the focus of this ticket: Less dungeons generate in recent version or Dungeons not generating at same positions anymore
That are different issues, pointless to have it in one ticket.

Lantien 2018-06-06T20:38:49Z

there are less all around ocean biome

those who were there are no longer there and there is no new generated next

Nick Sloan 2018-06-06T23:00:52Z

@Matt Can you provide evidence that the frequency is consistent with previous snapshots? I've been exploring in spectator mode on that seed and have only found one nearby outside of a mineshaft.

@Kumasasa In my opinion, the focus of the issue is that dungeons appear to be spawning less frequently. I think the correct approach to confirming this bug would be:

load n random seeds
inspect m random chunks in each seed
count the total number of zombie, skeleton and spider spawners in each inspected chunk
calculate an average number of dungeons per chunk

This all sounds easy, but I don't know of a way to do this efficiently and accurately in game. I'd be surprised if the Minecraft test suite didn't have automated tests to do something like this already.

PythonGB 2018-07-13T18:06:03Z

Can confirm that this is still present in Pre-Release 8. Just tried recreating a seed from 18w16a that had a quad zombie spawner in Pre-8 and all 4 of the spawners weren't there (as evident in the screenshots) - I agree with Nick Sloan in that this should be looked at as dungeons appear to be spawning less frequently...

[media]

Seed in question is this
-7866897547630675894

ZombieBaby 2018-07-20T13:52:10Z

Can confirm this is still an issue in major version 1.13, using the same example that PythonGB gave above.

Christian Rau 2018-07-20T13:54:50Z

Is this related to MC-131462 by any chance?

kumasasa 2018-07-20T14:03:06Z

Possible. Linked.

simon 2018-07-25T14:32:01Z

Yes this correct. I can confirm this is the case. i too am getting this problem in my world. far less dungeons are being generated and this is also the case for guardian temples.

I am using the 1.13 release and when i look at the 1.12.2 for every 1 dungeons in 1.13 there is 4 in 1.12.2 this from me looking at my see and writing down the locations then flying to those chunks and looking around

qwerty23495 2018-07-25T14:39:15Z

Dungeons spawn much differently than other generated structures; I do not think it is related.

Oleksandr Stepanenko 2018-08-16T15:02:06Z

It can be easy tested:

In 1.13+ choose a seed, generate a region file completely (for example r.0.0), then search in the region file with NBTExplorer for Name:"id", Value:"minecraft:mob_spawner". Write down zombie, skeleton, spider spawner counts.

In 1.12.2 use the same seed, generate the same region file, open it in MCEdit-Unified, select 32x32 chunks corresponding to the region and search for block "monster spawner" with BlockFinder_v1 filter. Teleport to the coordinates and write down the count and the type of the spawners.

I have tested 3 seeds so far and it seems 1.13+ versions generate not less but more dungeons! Just in different locations. Anyone may test more seeds, more biomes and if it is the case, then I'd say it works as intended.

UPD. Seed -2095774850092795097, regions 0.0, 0.1, 1.0, 1.1 (coordinates x, z ∈ [0, 1024)).
Here are my results for the numbers of all types of mob spawners in the area (counted manually by the methods described in this comment):

	1.13.1-pre1	1.12.2
Cave Spider	31	21
Zombie	13	10
Skeleton	7	7
Spider	8	5

user-57e18 2018-08-17T14:30:30Z

I've asked @unknown about it, and he asked @unknown about it, and it's now confirmed WAI.

skribe 2018-08-17T15:34:17Z

@unknown tried your method on my server seed. 1.13 has 1 spawner. 1.12.2 has considerably more in the same region.

kumasasa 2018-08-17T18:56:01Z

@unknown, bad luck with your seed?

Oleksandr Stepanenko 2018-08-17T20:54:22Z

@skribe, let me test it myself. Please tell me your seed and the range of coordinates where you were looking for dungeons. I am genuinely interested to have all major world generation issues resolved before I create a new longterm world.

skribe 2018-08-18T13:44:47Z

@unknown

Seed: 5810358736862867128

Region: r.0.0

Try this one too if you're particularly keen =)

Seed: 7452477466514423488

@unknown

Possible but the 1.12.2 version (same seed) had a good number. The other seed I listed above is also dungeon poor in 1.13.

Thanks!

Oleksandr Stepanenko 2018-08-18T15:10:03Z

@skribe

So here are my testing results:

Seed 5810358736862867128

1.13.1-pre1

Skeleton /tp 172 16 21

Skeleton /tp 165 41 220

Skeleton /tp 215 13 458

Zombie /tp 291 31 395

Skeleton /tp 385 31 422

1.12.2

Zombie /tp 64 42 493

Spider /tp 103 26 51

Zombie /tp 139 37 198

Zombie /tp 153 23 490

Zombie /tp 241 27 468

Zombie /tp 384 26 166

Zombie /tp 390 33 474

Skeleton /tp 476 11 491

Skeleton /tp 492 30 410

Seed 7452477466514423488

1.13.1-pre1

Zombie /tp 13 50 12 (Notch Apple in a chest by the way)

Skeleton /tp 188 39 72

Skeleton /tp 199 53 62

Spider /tp 270 33 389

Zombie /tp 414 25 461

Zombie /tp 509 44 429

1.12.2

Zombie /tp 60 69 51

Spider /tp 70 57 60

Spider /tp 81 30 213

Skeleton /tp 233 52 268

Zombie /tp 408 45 60

The first seed has its 0.0 region almost entirely under the ocean. Maybe dungeons don't generate in the new flooded caves? Thus there are quite less of them in the new version under such conditions. Still there are a few of them, not only one.

The second seed however has more dungeons in the new version than in the previous.

It is worth noting that choosing only one region file with so few dungeons inside leads to considerable statistical errors so I would advise to use atleast 3x3 regions if you can automate the process in any way. To conclude I have tested 6 seeds so far (one of them I plan to play on - with 4 region files) and only one of them has less dungeons than in previous version. And that seed may has many flooded caves in the area 1.12.2 version doesn't have.