Mob pathfinding AI does not regard some blocks as obstructions and is unable to pathfind on top of them

This issue relates to MC-94115 / MC-50556 / MC-94831

Still in 18w22c

Also relates to MC-142817 (partially)

Confirmed in 1.14 snapshots ! (19w12b)

Still in 19w13a

Still in 19w14a

Still in 19w14b, it specifically effects villagers with lanterns and flower pots

Still in 1.14 Pre-Release 1

Still in 1.14 Pre-Release 2

Added screenshots for 1.14 Pre-Release 2

Very easy to find these, in almost every desert village.

Still in 1.14 pre-3, 1.14 pre-4 and 1.14 pre-5

Still in 1.14 Release

Fences are affected too.

this bug is related to MC-134847

Most likely related to path-finding as well, so I'll instead add to the issue here:

Mobs get stuck on top of half blocks, whether or not they can collide with them (this in Minecraft Java Edition, version 1.14.1 Pre-Release 2):

Scenario 1: Natural occurrence.-

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These foxes attempt to catch the fish underwater, but get stuck on top of the kelp or sea grass.

Scenario 2: Provoked

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In this case, despite seemingly having a continuous path underneath them, the mob will spin in place in a failed attempt at finding the path to its target.
A similar issue of path-finding appears to occur with the villager getting stuck inside a space enclosed with open trapdoors. It most likely happens since it's not taking into account the new 'open' state the trapdoor is in, this since the villager is just pushing himself towards the edge of the trapdoor instead of jumping.

@unknown, your issue is MC-136318.

@violine1101
I see, I believe the filters I set to see if there was already an issue like mine were too limiting. Should I move that comment there or delete it, since the info I add is pretty much already covered there?

Still in 1.14.1 Release

(1.14.1van/Win 10/i7/16 GB)
Special for villagers concerning flower pots with cacti:
Usually, villagers will just run across any flower pot, but they get stuck at any flower pot with a cactus inside.

Still in 1.14.2 Pre-Release 1 and 1.14.2 Pre-Release 2

(1.14.2v on i7/16GB/Win10)

Can we please add trapdoors to this, or are they really meant to trap animals and villagers?

I have an entire village population (including foxes) trapped in the trapdoor decorations of their village…

@unknown, that's a separate issue, see MC-50556.

This issue is still in 1.14.2 and Pre-release 2 for 1.14.3

According to MC-154430, campfires are affected as well.

Was directed here from my other bug report here - MC-156334

Villager pathfinding can cause them to be stuck in various configurations when an obstacle is in the way of their 'escape' -

1 - Trap doors in an open position (single trapdoor where they stop instead of hopping over if there's enough space above), or double trapdoors - they will walk up to the double trap door and just stand there instead of path-finding around)

2- Top-side slab (1/2 block above the ground level where the villager is) with a double carpet over it. The villager will approach it and constantly jump.

3 - A double carpet at ground level - The villager will approach the carpet and just stand there.

4 - Water-logged stairs. Villagers will spin for about 10 seconds before attempting to cross. Water-logged slabs are ok.

5 - Fence block in the ground with an obstruction 3 blocks up. The villager will attempt to cross the fence, but can't, even if there is an opening.

(Interestingly enough, when I tried this with a fence gate, the villager did not choose a profession until the fence gate was opened. In all of the other tests, they chose a profession, so they saw a path as valid).

Still in 19w35a

In 19w37a

In 19w39a

In 19w40a

For god sake fix this please. Still an issue in 19w46b. My village is effectively useless as all villagers get stuck on every bloody flowerpot placed on the floor, where there are two blocks headroom. See pic.

In 20w12a

A workaround for flower pots (would need some work for a survival implementation, and you have to wait till something's in the pot)

Armor stand position can be adjusted to make it work for any of these blocks that are affected.

Link: https://pastebin.com/raw/m4qBS0MF

Notes:

• <x y z> being the coords of the flower pot, must be run in a command block because of length

• command in pastebin because Jira formatting is dumb

Can't believe that this is gonna be fixed in the next snapshot... FINALLY!!!

The fix will make all of the blocks in the description be regarded as solid, except ladders. These is a separate bug for ladder pathfinding.

The fix also makes waterlogged stairs, slabs etc be regarded as solid, not as water.

This bug is only about blocks that should be regarded as solid. I did not fix other pathfinding issues, e.g.

• Mobs don't understand ladders, scaffolding, or vines

• Trapdoors...

• Carpets - some mobs would work better if we treated carpets as solid, but other mobs would work worse.

• The empty block above a fence is regarded as empty but should be regarded as solid

@ Matthew Gatland
In regards to Carpets and specially villagers and this ticket MC-97799 It first became a problem after you changed the height of Villagers in v. 1.9 from 1.8block to 1.95block, before version 1.9, Villagers had no problem walking throug doorways with carpet in front.
Possible solutions:
1) Change Villagers Height back
2) Change height of carpet/change collision of carpet
3) Update the structures of Village buildings where there's carpet infront of the doorways (This is rather odd, since you knew about the bug before 1.14 yet some of the new structures, such as "snowy_masons_house_1" have carpet in their doorways rendering the building unusabel by villagers)

So I have done some testing in the latest snapshot 20w17a and found there are still a couple of blocks mobs do not regards as an obstruction.

The following blocks are affected:

• Daylight Detector

• Lit Campfire (they do however see an unlit campfire as an obstruction)

• Lit Soul Campfire (they do however see an unlit soul campfire as an obstruction)

• Snowlayers 2-4

• Open Shulkerbox

• Honey Block

• Occupied Boat (empty one aswell however they will board this)

• Lily Pads

See attached screenshots.

Note: I have not tested this with every mob in the game but with villagers and zombies.

They also don't regard turtle eggs as obstructions.

Oh yeah, I forgot to test those.

Shulker Entities are also not considered obstructions

This is still present in 20w18a in regards to the object I listed in my above comment.

Should I create a new ticket for these?

Yes, please. Shulker entities are not blocks and thus not really covered by this ticket.

New ticket MC-181565