N3rsssss
- N3rsssss
- JIRAUSER796702
- Europe/Stockholm
- Yes
- No
MC-278182
Affects versions 1.14 to 24w54a as of now!
Item entities can glitch inside the piston's head b36 upon being moved. This is due to the item entity being in a "mod4" status, and, when piston tries to move the item entity, this will move less due to the cobweb/powder snow slowdown.
This issue is specially bad since powder snow being introduced (1.17) but it can be replicated in 1.14 with cobweb.How to replicate:
Open the world download attached in 1.14
Power the command blocks, which will summon multiple item entities
Power the pistonExpected behavior:
All entities move towards the next block, and exact same position for all
Actual behavior:
Some entities glitch inside the piston head. This means they'll all randomly spread across the block.
As mentioned earlier, this issue becomes specially problematic for powder snow (1.17+), since this can be moved by pistons. Powder snow is very commonly used for item aligners, to slow down entities, etc. It is crucial to fix this issue. A video showcasing the issue will be attached too.
Affects versions 1.14 to 24w54a as of now!
Item entities can glitch inside the piston's head b36 upon being moved. This is due to the item entity being in a "mod4" status, and, when piston tries to move the item entity, this will move less due to the cobweb/powder snow slowdown.
This issue is specially bad since powder snow being introduced (1.17) but it can be replicated in 1.14 with cobweb.How to replicate:
Open the world download attached in 1.14
Power the command blocks, which will summon multiple item entities
Power the pistonExpected behavior:
All entities move towards the next block, and exact same position for all
Actual behavior:
Some entities glitch inside the piston head. This means they'll all randomly spread across the block.
As mentioned earlier, this issue becomes specially problematic for powder snow (1.17+), since this can be moved by pistons. Powder snow is very commonly used for item aligners, to slow down entities, etc. It is crucial to fix this issue. A video showcasing the issue will be attached too (recorded in 1.21).
Affects versions 1.14 to 24w54a as of now!
Item entities can glitch inside the piston's head b36 upon being moved
. This is due to the item entity being in a "mod4" status, and, when piston tries to move the item entity, this will move less due to the cobweb/powder snowslowdown.
This issue is specially bad since powder snow being introduced (1.17) but it can be replicated in 1.14 with cobweb.How to replicate:
Open the world download attached in 1.14
Power the command blocks, which will summon multiple item entities
Power the pistonExpected behavior:
All entities move towards the next block, and exact same position for all
Actual behavior:
Some entities glitch inside the piston head. This means they'll all randomly spread across the block.
As mentioned earlier, this issue becomes specially problematic for powder snow (1.17+), since this can be moved by pistons. Powder snow is very commonly used for item aligners, to slow down entities, etc. It is crucial to fix this issue. A video showcasing the issue will be attached too (recorded in 1.21).
Affects versions 1.14 to 24w54a as of now!
Item entities can glitch inside the piston's head b36 upon being moved, if they are inside cobweb/power snow, and under some special conditions.
This issue is specially bad since powder snow being introduced (1.17) but it can be replicated in 1.14 with cobweb.How to replicate:
Open the world download attached in 1.14
Power the command blocks, which will summon multiple item entities
Power the pistonExpected behavior:
All entities move towards the next block, and exact same position for all
Actual behavior:
Some entities glitch inside the piston head. This means they'll all randomly spread across the block.
As mentioned earlier, this issue becomes specially problematic for powder snow (1.17+), since this can be moved by pistons. Powder snow is very commonly used for item aligners, to slow down entities, etc. It is crucial to fix this issue. A video showcasing the issue will be attached too (recorded in 1.21).
Affects versions: 1.0 to 24w54a.
Issue:
Pistons fail to push entities fully when the entity has a movementMultiplier. This can be caused by the "velocity slowdown" effect from blocks like powder snow or cobwebs (via the onEntityCollision() method). This is related to MC-278182.Expected behavior:
The armor stand is properly pushed into the block in front of the piston.
Observed behavior:
The armor stand is barely moved by the piston, causing its hitbox to overlap with the piston head.
Code explanation:
When pistons move entities, they use the public void move() method from Entity.class.
The move() method always multiplies the entity's movement by any movementMultiplier affecting it.
As a result, even though the piston attempts to move the entity to a specific location, it fails because the entity’s hitbox collides with a block that has slowdown properties (e.g., powder snow or cobwebs).
Suggested fix:
This could be resolved by excluding piston movement from the slowdown effect, using a condition such as:
(if (this.movementMultiplier.lengthSquared() > 1.0E-7) → if (this.movementMultiplier.lengthSquared() > 1.0E-7 && type != MovementType.PISTON)).
Why fix this:
While this issue may not significantly affect most entities (as the primary outcome is the entity not reaching its intended position), it is problematic for entities that rely on the pushOutOfBlock method, such as items. See the related bug report: MC-278182.
A video recorded in the latest version will be attached, though this issue can be replicated in versions as old as 1.0.
Affects versions: 1.0 to 24w54a.
Issue:
Pistons fail to push entities fully when the entity has a movementMultiplier. This can be caused by the "velocity slowdown" effect from blocks like powder snow or cobwebs (via the onEntityCollision() method). This is related to MC-278182.Expected behavior:
The armor stand is properly pushed into the block in front of the piston.
Observed behavior:
The armor stand is barely moved by the piston, causing its hitbox to overlap with the piston head.
Code explanation:
When pistons move entities, they use the public void move() method from Entity.class.
The move() method always multiplies the entity's movement by any movementMultiplier affecting it.
As a result, even though the piston attempts to move the entity to a specific location, it fails because the entity’s hitbox collides with a block that has slowdown properties (e.g., powder snow or cobwebs).
Suggested fix:
This could be resolved by excluding piston movement from the slowdown effect, using a condition such as:
(if (this.movementMultiplier.lengthSquared() > 1.0E-7) → if (this.movementMultiplier.lengthSquared() > 1.0E-7 && type != MovementType.PISTON)).
Why fix this:
While this issue may not significantly affect most entities (as the primary outcome is the entity not reaching its intended position), it is problematic for entities that rely on the pushOutOfBlock method, such as items. See the related bug report: MC-278182.
A video recorded in the latest version will be attached, though this issue can be replicated in versions as old as 1.0.
This is NOT a bug. It is a consequence of 2 perfectly intentional features:
It is also NOT related to https://bugs.mojang.com/browse/MC-278182 , as this is not an intended feature, but rather a mistake from mojang developers
This is not a bug.
It is the consequence of pushing item entities into a wall/floor. When the piston attempts to move any entities (through `pushEntities` method) it will use `move()` method from `Entity.class()`. Because the entity will collide against the block on the bottom, it will fail to be pushed by the piston, glitching inside it's head.
The expected behavior is the behavior that is being reported as a bug:
Additionally, it is not related to MC-278182 . One is a consequence of 2 intentional features:
The other (MC-278182 ) is a mistake from mojang developers
There's your mistake. The issue isn’t with the entity itself. Instead, the item is summoned and pushed by the piston. A few game ticks later, the piston block entity completes its extension. At that point, a block suddenly appears where the item entity was originally located (glass pane instantly connecting upon shape update).
As I said earlier, it is the consequence of multiple, perfectly intentional behaviors.
Items do not end up inside the collision box, but rather the block ends up where the item is (it also does not happen in gt0, but a couple gt's after). Not a bug
this issue is related to
MC-278255, not MC-204423 nor MC-11293MC-211096 would describe this issue. Nonetheless, it does not focus on the buggy behavior seen in MC-278182. Due to item entities making use of the method pushOutOfBlocks, the outcome is unpredictable and causes issues for lots of mechanisms used in TMC.
Can confirm in 24w45a.
This bug is related to this bug report too: MC-278182
It is crucial to fix this bug for proper, consistent behavior from item entities when moved by pistons
haykam's bug solution would be valid, as explained here:
MC-278255Furthermore, powder snow can cause the same bug too (1.17+ as the block was introduced back then)
This is not a bug! Specially hoppers ignoring PickupDelay.
Fixing this would screw over the entire community in an unimaginable way. The vast majority of farm collections would break.