Detail provided by [~GoldenHelmet]
In the current release tripwire hooks activate immediately when tripwire connected to them is tripped, and they deactivate 1 redstone tick after the tripwire is un-tripped. That is, when an entity AABB overlaps the tripwire collision box the tripwire hooks visually move down in the same tick and they power the block they are attached to in the next redstone tick. When an entity AABB no longer touches the tripwire the hooks visually move up in the next redstone tick and stop outputting power in the redstone tick after that.
In the 1.20.30.20 Preview tripwire hooks delay activating or deactivating for 0.5 seconds after the tripwire connected to them is either tripped or un-tripped. During this time, hooks that are connected to tripwire at their South (+Z) or West (-X) sides disconnect from the tripwire. The disconnection is a visual update (the hooks visually move high up as if no tripwire is present), a server-side block update (the disconnect and subsequent reconnection can be detected by an observer), and a redstone update (the hooks do not ouptut redstone power while disconnected). With regard to tripped tripwire, when the disconnected hooks reconnect after the delay, they only go to the activated (down) position and output redstone power if the entity AABB is still touching the tripwire at that time.
Steps to reproduce
Build the directional testing module as shown.
[media]
Move into and out of the tripwire in the center while watching the hooks. Try this both slowly and quickly.
Move into and out of the tripwire in the center while watching the redstone dust. Try this both slowly and quickly.
Run or fly through the tripwire.
Expected results
Within each test, each hook and each redstone dust line updates in the same way as the others. The updates occur immediately (or as close to immediately as possible, i.e. with delays of no more than 1 redstone tick or 0.1 seconds between) after tripping or un-tripping the tripwire.
Observed results
Generally, activation and deactivation of the hooks and redstone lines is delayed for 0.5 seconds after tripping or un-tripping the tripwire. During the 0.5 second delay the hooks to the North (-Z) or East (+X) of the tripwire (i.e. the hooks attached to tripwire at their South or West) disconnect from the tripwire visually and do not power their blocks and redstone dust while disconnected.
Summary of broken mechanics discovered so far:
doesn't send signal across chunk borders
delay before output signal is way too high (approx seven redstone ticks)
doesn't trigger when run (or flown) through
Original impetus for this ticket
It seems that when a tripwire is triggered by an entity that also partially passes through the hitbox of one of the hooks, the block behind the hook will not output a redstone signal.
Might need to make this a separate ticket, but possibly related, the tripwire seems to be triggering much earlier than it used to, at least in the case where a snow golem is right in front of the tripewire before it fires its triggering snow ball.
I've attached the following
video showing the asymmetric redstone signals
video showing workaround for for broken timings
video from non-preview version 1.20.12 showing expected symmetric firing and timing
Linked issues
Attachments
Comments 5
Uploaded two worlds. They should be basically the same, but one was exported from the preview version, and the other from current release. Both should be broken in current preview, but for sure the "WorkingInCurrentRelease" world should work in non-preview.
Included both files as the one exported from preview edition has better labeling of the various bits, and can be used as a reference for the other. Also not sure if current preview exports are backwards-compatible with current release.
And uploading one more video of another broken tripwire mechanic: moving quickly through the trip wire (e.g. running) doesn't trigger it.
Possibly related to underlying cause of MCPE-171429 or the fix for that issue.
Just added a picture showing chunk borders, which are no doubt implicated in the asymmetric firing, but perhaps the timing is a separate bug.