The bug
Banners don't move in wind when over certain Time
value of the level.dat
.
Code analysis (by @unknown)
The following is based on decompiled version of Minecraft 1.8 using MCP. All method and class names are the names used in the decompiled version.
The Time
value of the level.dat
file is used for rendering banners, beacons (they are affected by this in 1.8 but not in 16w06a anymore) and guardians (can't find any problems here). If I understand it correctly, the conversion from long
to float
is with high numbers too lossy:
1000000696956L = 1000000720000f
1000000701016L = 1000000720000f
In the case of the banner using % 100L
of the time should create the same moving animation but prevent this from happening.
Related issues
is duplicated by
relates to
Comments


Only on servers
come join 83.83.203.234

does making a new map fix the issue.

Yes it does, but does that mean they will never move on the old map?

Nope, just means your report isn't correct and should be redone, but please don't make a new one just yet, I don't exactly want to have to deal with duplicates. I'll get back to you.

Do you still have this issue in 14w31a

yes, the server kept crashing so I tried it in singleplayer and it doesn't happen there eighter.

Happening in 14w32b as well.

Same problem.

Please force a crash by pressing F3 + C for 10 seconds while in-game at the place where it occurs and attach the crash report ([minecraft|http://hopper.minecraft.net/help/finding-minecraft-data-folder]/crash-reports/crash-<DATE>-client.txt
) here.

Forced a crash report for you.

Still happening in 14w24b, haven't tried c yet but can say I found a duplicate: MC-64204

Still is an issue in 14w34d. To make clear. Banner sways in newer map (superflat test map I made) and on an older single player map (made on 8/3/2014) but does not sway in older multiplayer map (made 8/1/2014).

Still an issue in 1.8-pre1, Banners don't sway in old worlds.

Do the banners sway in worlds created in 1.8-pre1 (single / multiplayer) ?
If so, this is also caused by MC-58120

They do in new worlds. But it's not that they move really slow, they just don't.

But the banners still don't move on my older world

@@unknown: Yes. Delete the world or use your pre-14w30c backup.

I'm not sure if delete the world or use an old version is considered a solution...

@@unknown: This cause of this issue got introduced in one of the 1.8 snapshots. That snapshots should never be used on production worlds, since snapshots may (and will) introduce bugs in your worlds. Therefore it's indispensable to make backups before each snapshot. You've been told so by checking the "Snapshot" checkbox in the Launcher.

Ok everyone, I found sort of a fix for this problem.
To fix it you can copy your old world using mcedit and pasting it in a new world using the same seed.
doing that will fix the problem.

Confirmed on my SSP world. I think it only happens on 1.7 created worlds or older. Actually playing 1.8.

Happens in pre-1.8 created worlds. Happened with me. Why the heck is this invalid?

Because it was a bug introduced in some snapshots but fixed before the release.
Surely it still does happen in 14w3x-created worlds, but either take it or delete the world.

Confirmed for a SMP world created in Minecraft 1.0 (this world did never see any of the 14wXX snapshots)

I have this bug in my SSP world created in 1.3. It is in singleplayer worlds created before the 1.8 snapshots.

This bug also appears in pre-1.8 multiplayer world.

My two cents:
I bought an existing server from the owner, as I was a long time player./staff member and yea... Point being I'm not 100% sure when the actual world was created but I believe sometime in Sept of 2013 (1.5.2-ish?). It is an SMP CraftBukkit server, always has been. Never wanting to sign the EULA by going to CB 1.7.10, I kept it on 1.7.9 CraftBukkit (lol, I know), and then finally jumped straight to 1.8.1 CraftBukkit (not the protocol hack)..
No issues were or have been noticed until a few weeks ago while I had loaded up a Texture Pack Display world through MultiVerse plugin and noticed "Hey, banners sway, I didn't know they did that!"; however, if I went to ANY other world (all having been created under different versions), the banners had NO movement.
I also have a world that is in SSP, created sometime in 1.3 and as far as I'm aware never saw 1.7.10 but am quite certain it saw 14w30c. I just now went there and placed some banners... they DO move; however, it is VERY choppy (despite 80FPS). Being MC I figured that was just how it was intended to sway, as it is the same choppy animation present on the Texture Pack map.
I decided to see what happens in a world that has never touched 1.7.9/10 or newer snapshots, being last accessed in Jan 14 of 2014. Loaded, grabbed a banner, placed it... perfectly fluid banner movement! (caught me off guard, I spend so much time with my server I never have played with 1.8 in Single player to experience this)
Again, this map would've been created with whatever version was out at that date, never passing through any version other than 1.8.1 right now. Also, just for the record, framerate is only at 109FPS, but even limiting it to 65 it's fluidity is kept.
I do use OptiFine, but that appears to have nothing to do with what is being exhibited.
If this does get sorted, given I've dealt with "static" banners for so long, I'm not sure some of the designs I've made with them would look as good if suddenly banners were swaying again. As such I can only suggest something like a higher meta which is only obtainable in commands which creates a static banner.
Hope this helps....

Can a Mod please update the affected version to 1.8.4? Thank you!

Cannot confirm for
1.8.7 neither in singleplayer nor multiplayer

Can still confirm in 1.8.7 for older worlds.

SUGGESTION
While I've grown quite used to having Static banners, I will admit that one thing still bothers me quite a bit with their placement: they stand/hang they unnaturally slant away from either their post or the block they are attached to.
Example:
However... I do realize there is a logical purpose for that, as it allows them to overlap each other when "stacked" (placed) one on top of the other, preventing any clipping. That is nice and would be ideal to keep.
So what I propose is to accommodate the no doubt vast number of servers who run a map that is old enough to cause static-banners, by making a small conditional-change to banners:
For banners that are by themselves they will hang at exactly 90deg, be it to their post (free standing) or block (hanging).
For multiple banners stacked or hung, they will appear as they currently do, with the ~5deg slant.
Triggering Conditions for these changes would be any banner of the same state (standing or hanging) 1 block above or below on the same Y-axis.
[ Any that are placed in back, in front, to the side, next to, or even directly-onto another banner, would thus hang @ 90deg unless matching the trigger condition. ]

Can someone confirm this for 15w49b, I am currently unable to reproduce this

can confirm for 15w49b

I've seen this bug occur in Singleplayer in 1.8.9, and it seems to be related to the removal of mods, as it has occurred each time I've removed a mod (any mod, so far it does not seem to matter which) from the mod folder and loaded up a save that had been in use when the mod was still in, even if any relevant mod items/blocks had been removed.
It does not occur when adding mods, just when removing them.
I have previously only noticed it happen in multiplayer servers, as those tend to use mods on their end.
A thing of note, the bug affects banners from both Vanilla Minecraft and Thaumcraft 5.
Edit: I'd recommend to back up saves to zip files, and make at least two new worlds when testing mods out, as the bug may only affect the last two worlds that have been in use, even if they hadn't technically been in use with the mods installed.
I believe I've confirmed that beyond those two worlds, no other are affected.
If anyone else can confirm this, that would be helpful.
Edit 2: For SMP it appears that once a certain uptime value is reached, banners stop swaying until the uptime is reset in level.dat with an NBT editor.

and it seems to be related to the removal of mods
Maybe, but also happens in vanilla-only single player worlds.
IMO it's just a matter of world time.

@unknown it is, after I set my world time to 0 (with a NBT editor) they started moving with the wind again

Maybe, but also happens in vanilla-only single player worlds.
IMO it's just a matter of world time.
How long does it take to happen in SSP?

Confirmed for
16w06a
For a 16w06a world with Time
value of 1000000000000L in the level.dat
file

Please link to this comment in the description of the report.
The following is based on decompiled version of Minecraft 1.8 using MCP. All method and class names are the names used in the decompiled version.
The Time
value of the level.dat
file is used for rendering banners, beacons (they are affected by this in 1.8 but not in 16w06a anymore) and guardians (can't find any problems here). If I understand it correctly, the conversion from long
to float
is with high numbers too lossy:
1000000696956L = 1000000720000f
1000000701016L = 1000000720000f
In the case of the banner using % 100L
of the time should create the same moving animation but prevent this from happening.

Still a thing in Minecraft 1.9 Pre-Release 1

Still in the 1.9 release.

Confirmed in 1.9.2

Confirmed for
16w40a

Confirmed for 1.11.2

Can confirm for 1.12

Confirm that there is a problem with 1.12.1
And not only the main world does not swing
I have a screenshot in my question, and the banner will still swing in hell
According to WIKI
This should not happen
MC-120788
What the wiki says is not necessarily correct.

So ... the banner of hell will swing, is the correct phenomenon?
However, in my main world, the banner does not swing in any way

Confirmed for minecraft 1.12.2 with spigot 1.12.2
Time NBT from world: 596314945
Good luck!

Confirmed for 1.13.1.

Confirmed for 19w14b.
Hmm, the banners in my snapshot testing world don't move (19w40a). Might not be fixed, more testing is required.
Reopened. This is still happening in 1.15-pre2. To reproduce, I just set Time
in level.dat
to 1000000696956
.
Cannot reproduce this issue. Does it occur in a new SMP world.