The Bug
The contraption as shown in figure
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will create ghost blocks after running for some time.
How to reproduce
Load
Activate the observer as marked in figure shown above
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→ ❌ Ghost blocks will appear after some time as shown in figure
Ghost pistons seem to occur more frequently with some slight lag, thus potentially also more likely on SMP; in order to be able to reproduce this bug better in Creative or on SSP testworlds, insert:
/gamerule randomTickSpeed 100000
the contraption will more likely/faster produce ghostpistons then; if not, play around with the randomTickSpeed, but don't forget to set it back to the default value 3 when you're done.
Attachments
Comments 22
they aren't ghost blocks, and it did occur in singleplayer and also later i did the same thing on multiplayer
I could recreate this in 20w09a, however, for me it's ghost blocks (can walk on them, but as soon as I rightclick them or re-enter the world, they were gone).
I recorded it, just in case it's needed.
@unknown You resolved this bugpost as Duplicate of MC-54026, however, said bugpost is resolved as "Cannot Reproduce" - should that old bugpost be now reopened instead?
@unknown Reproduction steps: Load structure from
[media]Activate Observer, as shown here
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It may take sometime until ghostblocks are created, but there definitely will be.
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this bug happen when a blockevent try to push a moving block in the 1st or 2nd tick
here is some setup that make it more clear,trying to push at the 2nd tick:
[media]The reason is in PistonMovingBlockEntity.java (mojang mappings)
if the client dont receive a packet to turn the moving block back into a block,the block entity progress of the moving block will still increase clientside but the animation stop and a counter: "deathTicks" will increase
when it go over 5,the moving block block turn into a block clientside and remove the blockentity,so the block can be pushed clientside and create a ghost block
this can happen if there is a server side lagspike and the client can execute about 7~8 ticks before the next server tick
a solution could be raising that "deathTicks" limit, or removing it (I dont know the the effects, it could leave some glitched extending pistons when players have a bad internet conection, EDIT:bad idea, moved ghost blocks will just get stuck,they are already stuck for 6 tick after moving)
a solution could be comparing the tick of creation with the current tick because it's synced with the server tick and wont be affected by how many times the client tick
Are these "ghost" pistons or actual pistons? That is to say, when you place a block directly next to these pistons do they disappear? And just to confirm, did this occur in singleplayer?