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MCPE-14467

Hostile mobs are spawning on/in transparent blocks like slabs, fences, glass, etc.

I slabed off an area and put walls around hoping to prevent slime spawns in a some chunk area but they still spawn. I suspect that this might be related to MCPE-14022.

Linked issues

MCPE-15803 Mobs spawn on slabs Resolved MCPE-16077 Mobs spawn everywhere Resolved MCPE-18018 mobs are spawning on top of half slabs and rails Resolved MCPE-18428 Zombies getting stuck in oak trees Resolved MCPE-20497 Mobs can Spawn in transparent blocks Resolved

Attachments

Comments 61

Top-half slabs don't prevent any mobs from spawning. Only bottom-half ones do.
See http://minecraft.gamepedia.com/Spawn#Spawn_conditions

Joshua Michael Hess

I know that top slabs don't prevent spawns those are all bottom slabs and the slimes still spawn. Please reopen.

Tested on bottom slabs and confirmed.

[Mojang] Mega_Spud (Jay)

I think this bug might be more far reaching than just just Slimes.

I covered a fenced off 22x22 area of bottom-half slabs where I had seen a slime spawn on a flat world.

I couldn't get a slime to spawn (possibly needed more time!) but other mobs were spawning on the half slabs as pictured:

[media]
Joshua Michael Hess

Because of 14022 I suspected that this might be part of a more general bounds checking bug which would affect all mobs, but I had only seen the slimes spawn on the bottom slabs.

51 more comments

Update... Issue persists in beta 1.14.0.50.

Mobs are also spawning on leaf blocks. (Dark oak and spruce for sure. Haven't tested others)

SuperGeniusZeb

@Brad Canney, you should open a separate issue for mobs spawning on bedrock, since bedrock is not a transparent block.

Oh sorry. I should have included an update there too. I've removed the glass for 1/4 of my hole and The mobs don't spawn there. They most be spawning on the glass blocks

SuperGeniusZeb

@Brad Canney The issue with leaves and glass is being tracked at a new issue: MCPE-54241.

Current issues with spawning on leaves and glass are being tracked as MCPE-54241. You may want to upvote and/or watch that ticket instead.

Joshua Michael Hess

(Unassigned)

64299 / 106486

Confirmed

Phone - Android - Samsung Galaxy Note

Android 5.0

entity-spawning, fence, glass, mob, slab, transparent-block

0.14.3, 0.15.0, 0.15.4, 0.15.90.0, 0.15.7, ..., 1.2.3.3, 1.2.3.6, 1.2.13.6, 1.2.13.8, 1.2.13.10

1.2.5.12, 1.2.13.54

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