[MC-136051] Mob spawning ignores light level, biomes and height

Hostile mobs spawn on the surface despite light levels over 7.

Testing methodology: Create a new superflat world. To avoid slime spawns, I set dirt height to 64, though the effect happens at the default setting of 2.

Observation: Despite being day, hostile mobs spawn on the surface. This also happens inside well lit closed areas as well (see attachment).

Linked issues

blocks 1

MC-124156 Parrots aren't spawning on the bark or in fern, dandelion, poppy, tall grass and large fern Resolved

is duplicated by 13

MC-136053 Mobs are incorrectly spawned (ignore the light level, biome and so on) Resolved

MC-136054 Slime can spawn in Y=40+,even not need in swamp. Resolved

MC-136056 Monsters spawning during day Resolved

MC-136057 Mobs spawning in the day Resolved

MC-136058 Hostile mobs spawning in daytime like its night time Resolved

8 more links

relates to 1

MC-148504 Mobs not affected by sunlight Resolved

Attachments

Comments 18

Irbis 2018-08-15T15:14:47Z

can confirm

Irbis 2018-08-15T15:17:06Z

also slimes do not check height when spawning. Can spawn on any hight.

Rogers Lo 2018-08-15T16:17:56Z

Entering game on peace mode and daylight, mob seems still spawning.

[media]

Spirited_Away_ 2018-08-15T16:28:56Z

May also ignore biome, slime will spawn in any biome. (I am not sure whether or not only spawns on slime chunks), but slime will spawn on the surface even if it's not in the swamp.

[media]

Irbis 2018-08-15T16:34:01Z

I think biomes are still counted properly when spawning. Slimes spawn probably only on slime chunks.
Husks/strays spawn only in desert/cold biome as well.

8 more comments

InsaneJ 2018-08-15T17:15:01Z

Same here on a dedicated server.

Linux (amd64) version 4.4.8-hardened-r1
Java Version: 1.8.0_172, Oracle Corporation

Bret Ryder 2018-08-15T17:26:09Z

Me too.

Masses of mobs spawning in broad daylight at around Y:64. Bats also fluttering all over the place.

Daniel PRO 2018-08-15T17:42:21Z

Me too, I played world, Hostile mobs spawning zombies, skeletons, slimes, spiders, bats, and creepers.

omer gur 2018-08-15T19:02:03Z

Bats are spawning anywhere, too

Matt A. 2018-08-15T19:28:40Z

Also, an abnormal number of spawns. In the nether, ghasts spawn so quickly that you have half a dozen in the same place in the space of a minute or so.

rockenroll4life (Josh Letellier) 2018-08-15T21:17:22Z

This accidental issue will ignore all typical monster spawn behavioral checks (Peaceful, and light levels) as well as special mob rules for most mobs.

SolidBlock 2018-08-18T11:37:34Z

Seems that not ignoring biomes.

In 18w33a, zombie pigmans and ghasts are not spawned in the overworld, and zombies, skeletons and so on are not spawned in the nether and the end, too.

Also, on the mushroom islands, only mooshroom are spawned. So biomes are not ignored.

violine1101 2018-08-18T12:02:59Z

@unknown, this issue was fixed in 1.13.1-pre1. Please update your game if you haven't already.

SolidBlock 2018-08-19T01:11:05Z

I know it's fixed. Before being fixed, biomes seem not to be ignored.

TheDude 2018-08-23T13:41:19Z

I am still seeing the issue in 1.13.1

violine1101 2018-08-23T15:17:14Z

@unknown Are you sure? Mobs aren't spawning in daylight for me anymore at least.

Shawn Baird 2019-04-17T04:52:11Z

This issue is happening for me in 1.14-pre3. It is in the desert and it seemed like mostly it was just skeletons. I could watch them spawn in and out. They were not burning and getting close enough would trigger aggro. After watching a bit more I also saw spiders and creepers and even an enderman. It seemed somehow isolated to that specific area and seemed to persist after restarting the game. It's a hardcore game, but presumably that's not a reason for it.

Just to amend this I found another bug report specific to 1.14-pre3 that wasn't well written but pointed out the "Erase Cached Data" option for worlds that had been upgraded (in my case from 1.14-pre2). Using that option completely fixed my issue.

violine1101 2019-04-17T11:08:46Z

There's a new ticket for this issue in the 1.14 pre-releases: MC-148504