MC-126815Banner and treasure markers on maps show incorrect icons in multiplayer
The bug
In multiplayer, most banner markers on maps don't show the correct symbol. This is also the case for the X mark on buried treasure maps. Out of the new markers, only the markers for white, orange, magenta, light blue, yellow, and lime banners work correctly.
This affects singleplayer worlds with opened LAN as well (the host is not affected).
To reproduce
- Join a server or a LAN world
- Create a map
- For each banner color, put a banner in the area covered by the map
- Add each of these banners to the map by using right-click
- Notice that all except the banner colors mentioned above have an incorrect icon *
- Run /locate Ocean_Ruin
- Teleport to the given coordinates
- Loot the chests and find a buried treasure map
- Look at that buried treasure map
- Notice that the icon is not a X, but a white banner instead
*) If you look at the map in an item frame, some banners won't be visible at all, because they're using player markers which are hidden on a map in a frame.
The reason
According to wiki.vg, the "Icon" banner field has only a byte reserved for direction and type of the icon. Because of this, only 16 map icons can be represented that way. Hence, the 17th icon (pink banner) is actually sent over to the client as if it was the first icon (player marker), the 18th as if it was the second, and so forth.
This could be fixed by changing the "Direction" part of this byte to represent the color of a banner instead (since the banner markers don't have rotation). That way, there are 11 seperate icons which fit into that byte.
Original description
My son and I were playing multiplayer LAN in 18w10a and I had the new banner markers for the maps behave strangely. I was playing on his world that he opened to LAN, so I was the joining player. I do not know if this happens for additional players beyond one or not.
Being a cartographer of sorts, I love fiddling with anything related to the maps in game. I immediately started experimenting with the banners, creating markers on a map I pulled from creative.
Here is the description of what I started experiencing:
The first six banner colors display properly: White, Orange, Magenta, Light Blue, Yellow, and Lime.
The Pink banner won't display at all.
Starting with the Gray banner and continuing with Light Gray, Cyan, Purple, Blue, Brown, Green, Red, and Black, each one displays an inaccurate marker for the banner. They include a small green, white, and blue arrow (like the ones for an item frame map and when a player is walking around), a white X, a large upside-down red arrow, the large and small white player map dots, the woodland mansion icon, and the ocean monument icon, I believe in that order.
Looking at the possible map markers on the Minecraft wiki here:
https://minecraft.gamepedia.com/Map#Map_icons
it seems for some reason that this new banner marker feature is accessing markers that are not intended to be used for the feature itself but exist in the game.
I assume this is not intended as when my son clicks the same banners I put up or the ones he put up on his own they are normal banner colors. It is only when I try to click the ones I set or the ones that he set does this happen. It seems to be an issue with me being an additional player in his world.
Linked Issues
![[Mod] violine1101](../../../data/avatars/users/92858.png){kind=small}
Created Issue:
new banner markers for maps behaving strangely for additional players in LAN world
My son and I were playing multiplayer LAN in 18w10a and I had the new banner markers for the maps behave strangely. I was playing on his world that he opened to LAN, so I was the joining player. I do not know if this happens for additional players beyond one or not.
Being a cartographer of sorts, I love fiddling with anything related to the maps in game. I immediately started experimenting with the banners, creating markers on a map I pulled from creative.
Here is the description of what I started experiencing:
The first six banner colors display properly: White, Orange, Magenta, Light Blue, Yellow, and Lime.
The Pink banner won't display at all.
Starting with the Gray banner and continuing with Light Gray, Cyan, Purple, Blue, Brown, Green, Red, and Black, each one displays an inaccurate marker for the banner. They include a small green, white, and blue arrow, a white X, a large upside-down red arrow, the large and small white player map dots, the woodland mansion icon, and the ocean monument icon, I believe in that order.
Looking at the possible map markers on the Minecraft wiki it seems for some reason that this new banner marker feature is accessing markers that are not intended but exist in the game.
I assume this is not intended as when my son clicks the same banners I put up or the ones he put up on his own they are normal banner colors. It is only when I try to click the ones I set or the ones that he set does this happen. It seems to be an issue with me being an additional player in his world.
My son and I were playing multiplayer LAN in 18w10a and I had the new banner markers for the maps behave strangely. I was playing on his world that he opened to LAN, so I was the joining player. I do not know if this happens for additional players beyond one or not.
Being a cartographer of sorts, I love fiddling with anything related to the maps in game. I immediately started experimenting with the banners, creating markers on a map I pulled from creative.
Here is the description of what I started experiencing:
The first six banner colors display properly: White, Orange, Magenta, Light Blue, Yellow, and Lime.
The Pink banner won't display at all.
Starting with the Gray banner and continuing with Light Gray, Cyan, Purple, Blue, Brown, Green, Red, and Black, each one displays an inaccurate marker for the banner. They include a small green, white, and blue arrow, a white X, a large upside-down red arrow, the large and small white player map dots, the woodland mansion icon, and the ocean monument icon, I believe in that order.
Looking at the possible map markers on the Minecraft wiki it seems for some reason that this new banner marker feature is accessing markers that are not intended but exist in the game.
I assume this is not intended as when my son clicks the same banners I put up or the ones he put up on his own they are normal banner colors. It is only when I try to click the ones I set or the ones that he set does this happen. It seems to be an issue with me being an additional player in his world.
My son and I were playing multiplayer LAN in 18w10a and I had the new banner markers for the maps behave strangely. I was playing on his world that he opened to LAN, so I was the joining player. I do not know if this happens for additional players beyond one or not.
Being a cartographer of sorts, I love fiddling with anything related to the maps in game. I immediately started experimenting with the banners, creating markers on a map I pulled from creative.
Here is the description of what I started experiencing:
The first six banner colors display properly: White, Orange, Magenta, Light Blue, Yellow, and Lime.
The Pink banner won't display at all.
Starting with the Gray banner and continuing with Light Gray, Cyan, Purple, Blue, Brown, Green, Red, and Black, each one displays an inaccurate marker for the banner. They include a small green, white, and blue arrow (like the ones for an item frame map and when a player is walking around), a white X, a large upside-down red arrow, the large and small white player map dots, the woodland mansion icon, and the ocean monument icon, I believe in that order.
Looking at the possible map markers on the Minecraft wiki here:
https://minecraft.gamepedia.com/Map#Map_icons
it seems for some reason that this new banner marker feature is accessing markers that are not intended to be used for the feature itself but exist in the game.I assume this is not intended as when my son clicks the same banners I put up or the ones he put up on his own they are normal banner colors. It is only when I try to click the ones I set or the ones that he set does this happen. It seems to be an issue with me being an additional player in his world.
The bug
In multiplayer, most banner markers on maps don't show the correct symbol. This is also the case for the X mark on buried treasure maps. Out of the new markers, only the markers for white, orange, magenta, light blue, yellow, and lime banners work correctly.
This affects singleplayer worlds with opened LAN as well (the host is not affected).
To reproduce
- Join a server or a LAN world
- Create a map
- For each banner color, put a banner in the area covered by the map
- Add each of these banners to the map by using right-click
- Notice that all except the banner colors mentioned above have an incorrect icon *
- Run /locate Ocean_Ruin
- Teleport to the given coordinates
- Loot the chests and find a buried treasure map
- Look at that buried treasure map
- Notice that the icon is not a X, but a white banner instead
*) If you look at the map in an item frame, some banners won't be visible at all, because they're using player markers which are hidden on a map in a frame.
The reason
According to wiki.vg, the "Icon" banner field has only a byte reserved for direction and type of the icon. Because of this, only 16 map icons can be represented that way. Hence, the 17th icon (pink banner) is actually sent over to the client as if it was the first icon (player marker), the 18th as if it was the second, and so forth.
This could be fixed by changing the "Direction" part of this byte to represent the color of a banner instead (since the banner markers don't have rotation). That way, there are 11 seperate icons which fit into that byte.
Original description
My son and I were playing multiplayer LAN in 18w10a and I had the new banner markers for the maps behave strangely. I was playing on his world that he opened to LAN, so I was the joining player. I do not know if this happens for additional players beyond one or not.
Being a cartographer of sorts, I love fiddling with anything related to the maps in game. I immediately started experimenting with the banners, creating markers on a map I pulled from creative.
Here is the description of what I started experiencing:
The first six banner colors display properly: White, Orange, Magenta, Light Blue, Yellow, and Lime.
The Pink banner won't display at all.
Starting with the Gray banner and continuing with Light Gray, Cyan, Purple, Blue, Brown, Green, Red, and Black, each one displays an inaccurate marker for the banner. They include a small green, white, and blue arrow (like the ones for an item frame map and when a player is walking around), a white X, a large upside-down red arrow, the large and small white player map dots, the woodland mansion icon, and the ocean monument icon, I believe in that order.
Looking at the possible map markers on the Minecraft wiki here:
https://minecraft.gamepedia.com/Map#Map_icons
it seems for some reason that this new banner marker feature is accessing markers that are not intended to be used for the feature itself but exist in the game.I assume this is not intended as when my son clicks the same banners I put up or the ones he put up on his own they are normal banner colors. It is only when I try to click the ones I set or the ones that he set does this happen. It seems to be an issue with me being an additional player in his world.
new bannermarkersformapsbehaving strangely for additional players in LAN worldBanner and treasure markers on maps show the incorrect symbol in multiplayer
Banner and treasure markers on maps showtheincorrectsymbolin multiplayerBanner and treasure markers on maps show incorrect icons in multiplayer
relates to
is duplicated by
![[Mojang] Nathan Adams](../../../data/assets/gravatar/dinnerbone.png){kind=small}
[Mojang] Nathan Adams
is duplicated by
I've generalized this ticket; player markers generally don't appear on maps in frames, the fact that banners generate player markers at all is covered by MC-126815.
As CreeperMagnet_ said, it's very likely that it's actually intended that player markers aren't shown on maps in frames; as far as I know, there's code that specifically prevents exactly that.
Thank you for your report!
However, this issue is a Duplicate of MC-126815.
If you have additional information, please add it to that report.
Please search before reporting, as it's likely that one exists already.
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I did search and found MC-126815, some of the issues I found were described in MC-126815
but I also found some additional issues that were not described in that issue.
I found that the maps do not update with explored areas and the player icon does not move
toward the treasure indicator (white banner icon) so there doesn't seem any way to find the treasure.
![[Mod] Pokechu22](../../../data/avatars/users/92931.png){kind=small}
I can confirm that it's creating new map IDs ingame; using F3+I on the maps shows that server-side, it's allocating one new ID for each map, though interstingly client-side in singleplayer it isn't (Shift+F3+I). In fact, the whole contraption doesn't seem to be displaying anything in singleplayer, though I'm not entirely sure why (maps in singleplayer do weird stuff with serialization, see MC-126815 for an example).
UPDATE: The original version of the machine (which uses positive IDs) does work in singleplayer and both the client and server versions have the same command. Once negative IDs are introduced it stops working and the server has a bunch of new IDs that the client doesn't get. I haven't tested behavior in real multiplayer yet.
I did a second test with other high map IDs (1000000000 and 1000000001) and it seems to also behave like negative IDs, but I suspect that that's just the same reasignment code marcono mentioned. I still don't fully understand this behavior :/
Additionally for some reason I don't understand, the command block that fills stone refuses to run (though the command works fine when ran as a player), in both 1.13.2 and 19w03b singleplayer. That's probably unrelated to this bug, but it's still odd... Caused by a trailing whitespace in that command block, apparently MC-134545. I'm still researching this.
Confirmed. I changed the summary and description a bit, I hope you're fine with that.
To violine1101 - For sure. I'm not the greatest when trying to concisely explain stuff sometimes
Also didn't know about the thing with the treasure map. (Wasn't sure how to reply to your comment so just made a new one)
It should be noted that this doesn't affect singleplayer (and LAN game hosts) because locally, within the same client, packets are transferred in-memory, thus the map decorations don't get serialized and no information is lost.
The in-memory transfer is also the cause for
MC-86619.Noticed this bug when testing a LAN world yesterday in 18w11a
I had searched and found this issue, while some of the issues I noticed are described I found some additional issues that are not.
The maps do not update with explored areas and the player icon does not move toward the treasure indicator (white banner icon) so there doesn't seem any way to find the treasure.