[MCPE-120078] Exiting rideable (minecart, boat) places player in unsafe location (water, lava, inside blocks), and minecarts can no longer drop mobs into holes

The change "Added new logic for mobs dismounting rideable" breaks the minecart logic and boat exiting.

The following issues occur:

A player in a minecart going over an activator rail with solid blocks at a head height will suffocate, because the minecart prefers to put the player inside of solid blocks instead of on trapdoors, water, or a safe fall next to the track (see

[media]

).
Minecarts going over activator rails no longer drop mobs into holes, ruining many mob farms and villager transport systems.
It doesn't fix the issue with the boat, as you fall through when you get in water.

[media]

(MCPE-105535)
It doesn't fix the issue on the strider on going into lava.

I am unclear on what this actually fixes as the stated fixes are not actually not fixed and the the player/entities end up often put into more hazardous locations IE inside of blocks causing suffocation damage.

This is a regression that actually causes death in more condition then it prevents.

*Workaround by [~Auldrick]:*

See this comment for information on how to work around this problem.

Linked issues

relates to 1

MCPE-122593 Activator rails no longer eject mobs into holes and chutes Reopened

Attachments

Activator Rail Workaround.mcworld

Big ups.mp4

Fall through boat.mp4

Jump around.mp4

Mine cart Murders me.mcworld

Minecraft 2021.03.18 - 16.37.26.11.DVR_Trim_Trim.mp4

No port or starboard exit.mp4

Strider fire.mp4

Up you go.mp4

Comments 17

ReLiC38 2021-03-09T22:47:28Z

This change basically breaks any minecart mob-mover that dumps the mobs into a hole, as the minecart will not drop them into air. It would rather put them into a solid block to suffocate.

For boats, when you dismount in open water, you fall through the boat. Previous version would let you stand on the boat.

There is no beneficial change to dismounting a strider. you usually end up in lava unless you are right next to a block you could have rode the strider onto anyway.

This change seems unnecessary, was there a need for it??? What bug report was this change associated with, there was none attached to the change.

GoldenHelmet 2021-03-09T23:33:15Z

The change breaks almost everything I’ve ever built with activator rails and minecarts. For example, in this blaze farm the minecarts no longer drop the blazes into the hole: https://youtu.be/TctLFPJLN54

In this trading hall: https://youtu.be/0mGa3mTHAc0 (2:56) and many iron farm builds minecarts can no longer be used to drop villagers into cells.

Minecarts going over activator rails also no longer drop players inside of vines for automated movement.

ravinmaddhatter 2021-03-10T05:47:33Z

I think more to the point, this change actually REGRESSES the intended improvements. The player character will end up in a MORE dangerous situation more often then previous to the change.

I don't know who or what group was responsible for checking this improvement, but I cannot find a case where this change performed BETTER in 1.16.210 over 1.16.201 in putting a player in a safer place. The player ALWAYS ends up in the same place, equally safe place, or a more hazardous place as avoiding water at the cost of block suffocation damage is not safer. Check the world i have above, reconstruct in 1.16.201. and you will find that 1.16.201 results in not taking damage, where 1.16.210 does. Add this to the fact that the dirt blocks could be obsidian and the player without an efficiency 5 diamond pick would receive fatal damage in 1.16.210 and would receive 0 damage in 1.16.201

As a side note in 1.16.201. The player always ended up standing on the boat in water, In 1.16.210 the player ALWAYS ends up in the water counter to the change log statements unless the player is directly next to a block at equal or lower height to the boat, and in those cases it is inconsistent at best. Due to this change it is no longer possible to exit a boat in the middle of an ocean and fly away with an elytra because you ALWAYS are in the water and bedrock does not allow for flight mode to be entered in the water.

Forgetting about the impacts to builds that an individual has made, I have yet to see a case where the new change is safer than the old change in difficult conditions.

The change appears untested and haphazard at best.

[Mod] LateLag 2021-03-10T13:36:54Z

Why should minecarts drop entities into unsafe holes? in this specific case, there are no safe spots around (other than the water, arguably). The minecart tries to drop you on a place where you're not floating.

Auldrick 2021-03-10T14:02:01Z

I have used minecarts over activator rails in village trade classifiers to easily:

drop nitwits and other useless villagers into lava, and
drop villagers with preferred trades into their trading hall stalls.

This change ruins the ability to work with villagers without all those annoying workarounds to deal with their habitual lack of cooperation. And isn't that's why they get trapped in minecarts? I mean, what other use does an activator rail have, if not to let you put a mob where you want it?

7 more comments

ravinmaddhatter 2021-03-10T14:19:18Z

@LateLage Can you give an example of a place where this new method doesnt put you in a worse place or a less safe place? There are MANY times i would rather be falling then in obsidian suffocating with no way out.

If the game considered "suffocating" as MORE unsafe then falling I would be fine with this change. But Suffocating is 100% death for all mobs, where as falling a few blocks into water is a great way to store mobs.

GoldenHelmet 2021-03-10T14:35:35Z

The new behavior also produces a janky animation where mobs teleport around:

[media]

. Note, too, that this pillager is teleporting to avoid an open trapdoor, which is a block that mobs will normally pathfind on.

More bizarre behaviors:

[media][media]

About the boat, I can confirm that in 1.16.201 when exiting a boat in water I would stand on the boat, now in 1.16.210 I fall through it. Moreover, the new behavior only works when there is a solid block in front of the boat:

[media]

About striders, I can see how the new behavior is meant to search for a solid block next to the strider when the strider is in lava, however there are two problems:

It's actually very difficult to get in a position where this works. You have to stop the strider in lava that is right next to a solid block at the same level as the lava. It is much easier to just walk the strider onto the solid block. If you try to place blocks like bottom slabs to prevent the strider from walking onto the shore, then the player gets put in lava instead of on the slabs anyway.
When the strider is lava and the exiting player is put on a block next to the lava, the player catches fire from the lava! This seems to be related to the janky teleporting I showed above with minecarts.

[media]

ravinmaddhatter 2021-03-11T05:38:35Z

To me the important thing that it doesn't seem to be be consistent with the developers intent.

Rogue Cheddar 2021-03-18T23:56:07Z

I don't see this mentioned yet in the comments but whatever changes were made are causing players in my server to drop through solid blocks when being kicked out of a minecart by an activator rail. (See attached video). This happens inconsistently but frequently enough that I've advised all users on my server to avoid taking any minecart rides for now.

[media]

Justin Olson 2021-03-20T04:48:30Z

Here's an example I am running into where the player, or in this case a villager, is dumped into a "less safe place"

Minecart rail line is covered with solid blocks
Minecart rail line is surrounded by a wall of solid blocks, except on one side
The open side, has a transparent pathable block, e.g. an open trapdoor, coral fan, etc.
The activator rail should eject the entity onto the transparent block, letting them fall into a player intended kill chamber, or villager trading cell. Instead, the rail ejects the entity on top of the rail line, suffocating in solid blocks.

Not only does this behavior cause activator ejections to eject a player or entity into unsafe locations (suffocation), it is a regression from previous behavior, breaking most user created mechanisms utilizing activator rails (villager trading hall villager delivery, and hostile mob farm mob delivery), and should be prioritized as a regression. Every usage I have of activator rails in our worlds is currently broken, and most don't have a valid alternative solution (nether mobs (no water), and villager delivery (villagers pathfind in water)).

GoldenHelmet 2021-03-24T20:37:18Z

Even when there is a valid, safe surface to eject a player, the new mechanic will still place the player inside solid blocks next to the safe spot. This seems to be because the block check uses the activator rail location, but the ejection uses the player’s exact location, which is not centered on the activator rail because the minecart ejects the player as soon as its leading edge touches the activator rail. You can see this with non-player mobs, but while mobs will glitch into the right place, the player does not, presumably in accordance with the tolerance for client-server disagreement (MCPE-65094). The expected behavior is to eject mobs or players centered in the block to right of the activator rail, as it did in previous versions.

noob1884 2021-03-25T00:11:31Z

I have to thank Golden Helmet for finding me this report as I was sure that there must be a few hundred by now since this is such an important game feature for any serious minecraft player.

I was just testing activator rails on a single block wide rail with 3 block drops on either side. I was deposited onto the track instead of on one side or the other.

On mentioning this on the AM discord I was told that some new 'fix' seems to have been carried out without apparent awareness / consideration of the mechanics involved. Perhaps the ghost of lean manufacturing on the haunt?

i am also informed that a button placed over the drop seems to be the current workaround. Many thanks to golden helmet for informing me of arch thunder's workaround for this (yet to be tried). I'll update if there is anything to add to this

Philip C. Duldulao 2021-03-27T16:07:44Z

Can confirm, it affects 1.16.210. It happend to me yesterday and this really needs to be fixed.

Ninja Dankinate 2021-11-23T18:19:44Z

Even with the workaround, hoglins will path back onto my rail track from the trapdoors, and only inconsistently fall into my pit. Pit is 3x3 with trap doors along one side (1x3). Trap doors are lined perpendicular to the track, and all three are triggered with the observer string adjacent to the track.

All other mobs fall into the pit as expected.

Auldrick 2021-11-23T21:11:12Z

*Workaround* by [~Auldrick]

It's been a while since I looked at this report. In the meantime, I've discovered a simpler workaround that my experiments show works with hoglins and piglins. I'm attaching a screenshot.

[media]

Note that the glass blocks are used to reveal hidden details; you will probably prefer opaque blocks.

In case it's not easy to see what's going on, the detector rail simultaneously powers the activator rail and a redstone repeater. The activator rail shakes the mob out of the minecart onto the red glass block. Meanwhile, the repeater powers a block holding a redstone torch, which turns off the torch, which causes the sticky piston to retract the red glass block before the mob has time to move off it. The mob then falls through the hole, which in this demo drops it into lava but you could make it your 3 x 3 pit, a water stream, or anything else.

I have also attached a demo world, Activator Rail Workaround.mcworld

Ninja Dankinate 2021-11-24T06:49:05Z

Thanks @Auldrick for the update! The new workaround fixed my issue, and consistently drops all ground-based nether mobs in my 3x3 pit!

SuperLlama88888 2022-01-26T06:37:19Z

Unfortunately, Auldrick's workaround requires a one block gap between each segment, meaning that trading halls would have to have a two block gap between each villager.

On a world on a different machine than what I am currently using, I took a screenshot of my design. Note that these screenshots were taken on the 23rd of October last year (the issue was present back then), in the (most likely the) latest version, from a structure block.

[media]

There is a piece of string which the observer is detecting. The villager will be ejected onto the closed trapdoor (which is considered safe, unlike its open state), thus causing an update to the string which the observer will detect, powering the piece of redstone dust at the back. The repeater will read this signal and extend it, which will power the trapdoor and drop the villager into the cell. I remember testing with no repeater for no delay; however, the shorter pulse occasionally left the villager still on top of the trapdoor; it is likely, though, that the repeater delay could be shortened from four ticks while maintaining the functionality. (Note that with this design, the trapdoor will also pulse open after the villager has dropped down, due to the string being updated again.

Another important thing to note is that, in some orientations, villagers may be stuck on the sides of the open trapdoors; this can be fixed by hinging the trapdoor on a different block.

For those of you who are interested in the full design of my trading hall segment, here is a screenshot (literally the one above but uncropped) showing it (note that the pressure plate is waterlogged):

[media]