MC-41631Tall entities (enderman, ghast, large slime/magma cube, open shulker) don't activate some tripwire from another sub-chunk
The bug
When an entity is inside a sub-chunk (which is marked with blue lines when you have F3+G enabled) and it touches tripwire from sub-chunk above, this tripwire won't activate if it is two blocks higher than the border of the sub-chunk (for example a ghast at y=207 (16*13-1) does not trigger tripwire at y=210 (16*13+2)), but triggers tripwire at y=209 and 208.
Currently affects:
- Ghast
- Enderman
- Slime and Magma Cube with Size:5 or bigger
- Open Shulker
Also happens horizontally - in this case only 3 tripwire lines can be activated and it only affects slimes/magma cubes with Size:12 or bigger
Steps to Reproduce
1. Create a Superflat world with the preset
3;207*minecraft:stone;0;
2. Create a ghast cage (blocks around a 4x4x4 area to trap a spawned ghast) at ground level.
3. Place a line of tripwire through the top of the inner area.
4. Spawn a ghast inside.
Linked Issues
NormalAttachments14
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Created Issue:
Ghast doesn't trigger Tripwire
A ghast at y=207 does not trigger tripwire at y=210
What I expected to happen was...:
The tripwire should trigger as it is within the 4 high bounding box of the ghast.What actually happened was...:
The tripwire does not trigger from the ghast. The player entering the tripwire will trigger it, so the tripwire itself is not broken. When the whole setup is placed one level higher or lower, the tripwire works as expected.Steps to Reproduce:
1. Create a Superflat world with the preset 2;207x1;1;
2. Create a Ghast cage (blocks around a 5x5x4 area to trap a spawned ghast) at ground level.
3. Place a line of tripwire through the top of the inner area.
4. Spawn a Ghast inside.Environment
Windows XP,
Attachments2
Windows XP, Java 1.7 update 45
Works fine in 07a
2014-02-18_12.46.26.png
A ghast at y=207 does not trigger tripwire at y=210
What I expected to happen was...:
The tripwire should trigger as it is within the 4 high bounding box of the ghast.What actually happened was...:
The tripwire does not trigger from the ghast. The player entering the tripwire will trigger it, so the tripwire itself is not broken. When the whole setup is placed one level higher or lower, the tripwire works as expected.Steps to Reproduce:
1. Create a Superflat world with the preset 2;207x1;1; (3;207*minecraft:stone;1;1 in 14w31a)
2. Create a Ghast cage (blocks around a 5x5x4 area to trap a spawned ghast) at ground level.
3. Place a line of tripwire through the top of the inner area.
4. Spawn a Ghast inside.
![[Mod] Torabi](../../../data/assets/gravatar/torabi.png){kind=small}
A ghast at y=207 does not trigger tripwire at y=210
What I expected to happen was...:
The tripwire should trigger as it is within the 4 high bounding box of the ghast.What actually happened was...:
The tripwire does not trigger from the ghast. The player entering the tripwire will trigger it, so the tripwire itself is not broken. When the whole setup is placed one level higher or lower, the tripwire works as expected.Steps to Reproduce:
1. Create a Superflat world with the preset2;207x1;1; (3;207*minecraft:stone;1;1 in 14w31a)
2. Create aGhast cage (blocks around a 5x5x4 area to trap a spawned ghast) at ground level.
3. Place a line of tripwire through the top of the inner area.
4. Spawn aGhast inside.A ghast at y=207 does not trigger tripwire at y=210.
What I expected to happen was...:
The tripwire should trigger as it is within the 4 high bounding box of the ghast.What actually happened was...:
The tripwire does not trigger from the ghast. The player entering the tripwire will trigger it, so the tripwire itself is not broken. When the whole setup is placed one level higher or lower, the tripwire works as expected.Steps to Reproduce:
1. Create a Superflat world with the preset 3;207*minecraft:stone;0; (for older Minecraft versions use 2;207x1;1; )
2. Create a ghast cage (blocks around a 5x5x4 area to trap a spawned ghast) at ground level.
3. Place a line of tripwire through the top of the inner area.
4. Spawn a ghast inside.
Windows XP, Java 1.7 update 45
Windows 7, Java 1.8 update 25,
Windows XP, Java 1.7 update 45
Ghast doesn't triggerTripwireGhast doesn't trigger tripwire at particular world height
A ghast at y=207 does not trigger tripwire at y=210.
What I expected to happen was...:
The tripwire should trigger as it is within the 4 high bounding box of the ghast.What actually happened was...:
The tripwire does not trigger from the ghast. The player entering the tripwire will trigger it, so the tripwire itself is not broken. When the whole setup is placed one level higher or lower, the tripwire works as expected.Steps to Reproduce:
1. Create a Superflat world with the preset 3;207*minecraft:stone;0; (for older Minecraft versions use 2;207x1;1; )
2. Create a ghast cage (blocks around a 5x5x4 area to trap a spawned ghast) at ground level.
3. Place a line of tripwire through the top of the inner area.
4. Spawn a ghast inside.This appears to be a modular arithmetic issue, presumably in how the game checks if tripwire in one section is triggered by an entity in the lower section. A ghast at any height h (integer or floating point) with (h mod 16) > 14.0625 will fail to trigger tripwire in the third layer of the next section up, and if (h mod 16) > 15.0625, tripwire in the fourth layer should also trigger but fails to (eg. a ghast summoned at Y=15.5 will trigger tripwire in layers 16 and 17 but fails to trigger tripwire in layers 18 and 19).
![[Bot] Arisa](../../../data/assets/gravatar/mustek2.png){kind=small}
A ghast at y=207 does not trigger tripwire at y=210.
What I expected to happen was...:
The tripwire should trigger as it is within the 4 high bounding box of the ghast.What actually happened was...:
The tripwire does not trigger from the ghast. The player entering the tripwirewill trigger it, sothetripwireitself is not broken. When the whole setup is placed one level higheror lower, the tripwire works as expected.Steps to Reproduce:
1. Create a Superflat world with the preset 3;207*minecraft:stone;0; (for older Minecraft versions use 2;207x1;1; )2. Create a ghast cage (blocks around a5x5x4 area to trap a spawned ghast) at ground level.
3. Place a line of tripwire through the top of the inner area.
4. Spawn a ghast inside.This appears to be a modular arithmetic issue, presumably in how the game checks if tripwire in one section is triggered by an entity in the lower section. A ghast at any height h (integer or floating point) with (h mod 16) > 14.0625 will fail to trigger tripwire in the third layer of the next section up, and if (h mod 16) > 15.0625, tripwire in the fourth layer should also trigger but fails to (eg. a ghast summoned at Y=15.5 will trigger tripwire in layers 16 and 17 but fails to trigger tripwire in layers 18 and 19).
The bug
When an entity is inside a sub-chunk (which is marked with blue lines when you have F3+G enabled) and it touches tripwire from sub-chunk above, this tripwire won't activate if it is two blocks higher than the border of the sub-chunk (for example a ghast at y=207 (16*13-1) does not trigger tripwire at y=210 (16*13+2)), but triggers tripwire at y=209 and 208.
Currently affects:
- Ghast
- Enderman
- Slime and Magma Cube with Size:5 or bigger
Also happens horisontally - in this case only 3 tripwire lines can be activated and it only affects slimes/magma cubes with Size:12 or bigger
Steps to Reproduce
1. Create a Superflat world with the preset
3;207*minecraft:stone;0;2. Create a ghast cage (blocks around a 4x4x4 area to trap a spawned ghast) at ground level.
3. Place a line of tripwire through the top of the inner area.
4. Spawn a ghast inside.
Ghast doesn't trigger tripwire at particular world heightTall entities (enderman, ghast, large slime/magma cube) don't activate some tripwire from another sub-chunk
![[Mojang] Nathan Adams](../../../data/assets/gravatar/dinnerbone.png){kind=small}
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Windows 7, Java 1.8 update 25,
Windows XP, Java 1.7 update 45
![[Mod] Michael Wobst](../../../data/avatars/users/37868.png){kind=small}
relates to
The bug
When an entity is inside a sub-chunk (which is marked with blue lines when you have F3+G enabled) and it touches tripwire from sub-chunk above, this tripwire won't activate if it is two blocks higher than the border of the sub-chunk (for example a ghast at y=207 (16*13-1) does not trigger tripwire at y=210 (16*13+2)), but triggers tripwire at y=209 and 208.
Currently affects:
- Ghast
- Enderman
- Slime and Magma Cube with Size:5 or bigger
Also happens hori
sontally - in this case only 3 tripwire lines can be activated and it only affects slimes/magma cubes with Size:12 or biggerSteps to Reproduce
1. Create a Superflat world with the preset
3;207*minecraft:stone;0;2. Create a ghast cage (blocks around a 4x4x4 area to trap a spawned ghast) at ground level.
3. Place a line of tripwire through the top of the inner area.
4. Spawn a ghast inside.The bug
When an entity is inside a sub-chunk (which is marked with blue lines when you have F3+G enabled) and it touches tripwire from sub-chunk above, this tripwire won't activate if it is two blocks higher than the border of the sub-chunk (for example a ghast at y=207 (16*13-1) does not trigger tripwire at y=210 (16*13+2)), but triggers tripwire at y=209 and 208.
Currently affects:
- Ghast
- Enderman
- Slime and Magma Cube with Size:5 or bigger
- Open Shulker
Also happens horizontally - in this case only 3 tripwire lines can be activated and it only affects slimes/magma cubes with Size:12 or bigger
Steps to Reproduce
1. Create a Superflat world with the preset
3;207*minecraft:stone;0;2. Create a ghast cage (blocks around a 4x4x4 area to trap a spawned ghast) at ground level.
3. Place a line of tripwire through the top of the inner area.
4. Spawn a ghast inside.
Tall entities (enderman, ghast, large slime/magma cube, open shulker) don't activate some tripwire from another sub-chunk
![[Mod] turbo](../../../data/avatars/users/92867.png){kind=small}
The issue with tripwire is tracked at MC-41631.
While I appreciate the similarity, given that MC-41631 effects versions prior to 1.19 and the code review by Daniel indicates this issue is linked to a change made in 1.19 code I am not sure they are actually related. This is further supported by the fact I can not reproduce this issue in 1.16.5 or 1.17 either. The attached world (ShulkerTest1.17.zip
) exhibits the issue only when loaded in versions >=1.19.
Also confirmed this is still an issue in 1.19.2.
Is this still a concern in the current Minecraft version 14w06b / Launcher version 1.3.9 or later? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.
Change your map. It works everywhere for me (with another map).
Is this still a concern in the current Minecraft version 1.7.9 / Launcher version 1.3.11 or later? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.
Is this still a concern in the current Minecraft version 14w30c or later? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.
Same results with a matching world created from scratch in 14w31a (launcher 1.5.1, java 7 update 65) - the ghast trapped at ground level will not trigger the tripwire, but the whole setup one layer higher or lower works fine.
I did not re-test the attached world, and I don't remember where the engineering world where I first found the bug is, so I can't check that one.
The preset screen in 14w31a kept resetting the old custom preset after entering it, clicking Use Preset and then Done; the preset 3;207*minecraft:stone;1;1 works and I have updated the instructions above.
Cannot reproduce in 1.8.
Is this still a concern in the current Minecraft version 1.8.1 Prerelease 3 or later? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.
Cannot reproduce in 1.8.3. As you can see in the screenshot, the tripwire is at Y=10, the ghast was summoned at Y=7, and it's triggering the tripwire.
This issue is only known to happen at one particular combination of ghast height and tripwire height. The title was originally vague because I didn't (and still don't) know if this problem could be reproduced at any other particular combination of heights; I figured a title that was too specific might cause people to overlook that unknown, but apparently they aren't reading the important detail clearly listed in the description.
If you can't reproduce a bug, please don't post that you couldn't reproduce it until you've checked that you didn't miss something important in the description. A vague statement of inability to reproduce will mislead others looking over the problem and make those who have already reproduced the problem have to check it again (possibly leading to a vicious circle); giving details from the reproduction attempt helps to identify the problem but can also cause noise if it neither correctly tests the issue nor identifies another arrangement as also producing the problem ("Problem doesn't occur at <conditions not claimed to cause problem>" vs "Problem also found with <different conditions>").
It's reasonable for reviewers to not want to immediately download an untrusted file but I will add a demonstration world from 1.8.3, and a new screenshot showing the altitude in the debug overlay (in addition to the ghasts on each side already showing that the problem does not occur at every height).
This problem also occurs in Minecraft 1.3.1 (the first release featuring tripwire) but the Affected Versions field doesn't support adding a version that old.
This appears to be a modular arithmetic issue, presumably in how the game checks if tripwire in one section is triggered by an entity in the lower section. A ghast at any height h (integer or floating point) with (h mod 16) > 14.0625 will fail to trigger tripwire in the third layer of the next section up, and if (h mod 16) > 15.0625, tripwire in the fourth layer should also trigger but fails to (eg. a ghast summoned at Y=15.5 will trigger tripwire in layers 16 and 17 but fails to trigger tripwire in layers 18 and 19).
I may upload a demonstration world tomorrow (no promises).
Sorry, I assumed that the 207 coordinate was just an example, since the title just said it didn't trigger tripwire at all. Confirmed in 1.8.3.
I uploaded a Minecraft 1.8.3 world (Ghast Tripwire Sieve.zip) with a self-replicating setup to test multiple combinations of ghast and tripwire elevation.
Added screenshots of the test setup showing one of multiple locations where tripwire is failing to trigger (another spot 16 layers upward can be seen in the distance).
Is this still an issue in the most recent versions (currently that is 1.10.2, or 16w42a) of Minecraft? If so, please update the affected versions and help us keeping this ticket updated from time to time.
Can confirm in 1.17.1.