MC-102971Sudden loss of velocity while flying in mp
Problem:
When flying the player suddenly looses all momentum. As a result of having no speed, they stall and fall.
Notes:
- This does not appear to be a stall, although it causes one: There is no leg movement prior to it happening, and will occur even at relatively steep angles of descent.
- This is noted primarily when flying long distances in relatively straight lines.
- On the server side, this loss of velocity is often accompanied by the following error: "[07:04:32 WARN]: player moved too quickly! -0.76424263494755,-2.1542786152011217,18.745712770032128
- It does not appear to be location specific. I cannot reproduce it in any specific spot, but it does happen reliably whenever flying far enough to cause chunks to load.
- This only happens when playing on a server. I cannot reproduce the bug when playing in singleplayer.
Reproduction:
- Connect to a server
- aquire elytra
- climb something very tall
- jump off and establish a normal glide
- continue gliding in a straight line
- after a few seconds (when it starts to cause chunks to load), it should begin reseting the speed to 0 on a regular basis until flight has ended.
Expectation:
Flying through open air at a constant rate of attack sufficient to produce acceleration should result in a smooth, constant forward movement.
Environment
Windows 7 (fully updated), Java 8u91.
Hardware: AMD 4170, 16Gb RAM, primary drive is an SSD.
Server: Using .jar version downloaded from minecraft.net
Created Issue:
Sudden loss of velocity while flying in mp
Problem:
When flying the player suddenly looses all momentum. As a result of having no speed, they stall and fall.Notes:
- This does not appear to be a stall, although it causes one: There is no leg movement prior to it happening, and will occur even at relatively steep angles of descent.
- This is noted primarily when flying long distances in relatively straight lines.
- On the server side, this loss of velocity is often accompanied by the following error: "[07:04:32 WARN]: player moved too quickly! -0.76424263494755,-2.1542786152011217,18.745712770032128
- It does not appear to be location specific. I cannot reproduce it in any specific spot, but it does happen reliably whenever flying far enough to cause chunks to load.
- This only happens when playing on a server. I cannot reproduce the bug when playing in singleplayer.
Reproduction:
- Connect to a server
- aquire elytra
- climb something very tall
- jump off and establish a normal glide
- continue gliding in a straight line
- after a few seconds (when it starts to cause chunks to load), it should begin reseting the speed to 0 on a regular basis until flight has ended.
Expectation:
Flying through open air at a constant rate of attack sufficient to produce acceleration should result in a smooth, constant forward movement.Environment
Windows 7 (fully updated), Java 8u91.
Hardware: AMD 4170, 16Gb RAM, primary drive is an SSD.
Server: Using .jar version downloaded from minecraft.net
I almost never ran into this until 1.9.4, and I used spectator mode at high speeds a lot. But now I run into it a lot, particularly with Elytra.
(my own duplicate of this report: MC-102971, just for the record)
For those just coming across this bug due to its effects on Elytra, the following server command solves the problem for me:
/gamerule disableElytraMovementCheck true
Thank you Skylinerw for finding and pointing this out.
Possibly related: In the same multiplayer environment, when moving in spectator mode, if one starts moving too quickly it generates the same sort of thing: Assuming the forward movement key is held down, one zips along, then velocity keeps getting frequently - but irregularly - reset to 0, resulting in a very jerky movement pattern. This behavior usually occurs only when covering large enough distances to cause significant chunk loading. This is also accompanied by similar serving warnings along the lines of "WARN: player moved too quickly"
(I haven't made a bug report for this spectator behaviour because it may be related to this Elytra flight related issue)
See
MC-90062.Thanks for pointing that out. I searched, but didn't see it.
Just for the record, and anyone else getting this bug, it can be fixed by having whoever runs the server input the following command:
/gamerule disableElytraMovementCheck trueRunning this on my own server solved the problem for me.