This is a Bukkit plugin for Minecraft servers that allows overlapping pathways to be configured.
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Clients treat the wall blocks as real, but to the server the walls are only illusionary. They are never saved to the world file. The walls displayed by this plugin do not affect non-player entities including arrows and thrown ender pearls. The plugin stops mobs from targeting players through the illusionary walls in certain cases, but they may still pathfind and walk through them.
Here's a birds-eye diagram giving a barebones example of how an overlapping pathway works. The dots represent empty spots. P1 and P2 are two players. The center of the intersection is in the middle between the O and X characters. The P1 player will see walls where the X characters are. The P2 player will see walls where the O characters are. If P1 walks to P2's location, they will see the X walls disappear and the O walls appear. If instead P1 walks directly into the center, crossing the O walls (that only P2 sees), then P1 will become invisible to P2 as long as P1 is inside of the intersection in the path opposite of what P2 sees.
. . . P1. . .
. . . . . . .
. . . . . . .
. O O . . . .
X . . X . P2.
X . . X . . .
. O O . . . .
Ideally, you would build a structure around the O and X walls so that a player will never see the change, and will never see the backside of either.
This plugin depends on ProtocolLib. You must download its jar and place it in your plugins/ directory.
Download the latest NonEuclid jar file from the project's Releases page. Place the jar file in the plugins/ directory. After the first run, the file plugins/NonEuclid/config.yml file will be generated with default values.
By default, no overlapping locations are enabled. Multiple overlapping locations may be specified.
You create an overlapping pathway by specifying the center of the intersection, and then the height, width, and material for the illusionary walls in the config.
The config has a global max_distance setting, and individual locations may
override it.
The disabled setting allows a location to be easily left in the config while
disabled. The setting may be removed.
If a player connects to the server while standing inside of an intersection,
then the pathway specified by the default_path setting will be displayed.
This value may be "NorthSouth" or "EastWest".
This plugin records some usage metrics to
https://bstats.org/plugin/bukkit/NonEuclid. You can opt out of this by
placing enabled: false in plugins/bStats/config.yml.