Zone Spawner

A Paper plugin that lets you draw rectangular zones and auto-regulate a population cap per mob species inside each one - the classic "keep a farm stocked with exactly 20 cows, no more, no less" tool, but not limited to passive animals: any valid Minecraft 'EntityType' can be assigned to a zone.

see Entity Type list here

Quick start

1. Stand at one corner of the area you want to manage and run '/zpos1'.

2. Stand at the opposite corner and run '/zpos2'.

3. (Optional) Stand at actual ground level and run '/zpos3' if '/zpos1'/ '/zpos2' were marked somewhere else (e.g. up on scaffolding) - this tells the zone where its floor really is, independent of the corner heights.

4. '/zonecreate ' - creates the zone from your current selection.

5. '/zone set <entityType> <respawnRateSeconds> [leashRadius]'

   • configure a population rule, e.g.:

   /zone set farm COW 20 30 /zone set farm SHEEP 10 30 8

   Every 'respawnRateSeconds', the zone checks each configured species: if the count is under 'amount', it spawns one more (on solid ground, with 2 clear blocks above, within the zone's floor/height limits). 'leashRadius' (default 10 blocks) pulls any of this zone's own mobs back if they wander further than that from where they spawned - 0 means no leash.

Permissions

| Node | Default | Grants | | 'zonespawner.admin' | op | All of the above: creating, configuring, and deleting zones. |

Commands

| Command | Description | | '/zpos1' | Mark corner 1 of your zone selection at your current position. | | '/zpos2' | Mark corner 2 of your zone selection at your current position. | | '/zpos3' | Optional - mark your current position's Y as the zone's floor height. | | '/zonecreate ' | Create a zone from your current '/zpos1'/'/zpos2' (and optional '/zpos3') selection. | | '/zone set <entityType> <respawnRate> [leashRadius]' | Add/update a population rule for that species in the zone. | | '/zone remove <entityType>' | Remove a species' rule from the zone. | | '/zone list' | List all zones. | | '/zone info ' | Show a zone's world, corners, floor, height limit, and rules. | | '/zone delete ' | Delete a zone entirely. | | '/zone maxheight <blocksAboveFloor|0>' | Cap how high above the floor spawns are allowed (0 = unlimited). | | '/zone floor [y|reset]' | Manually set (or reset) the zone's floor Y, independent of its corners. |

How population tracking works

Every mob this plugin spawns is tagged via 'PersistentDataContainer' with the name of the zone that owns it, plus its exact spawn location. A zone's count is "how many living, tagged mobs exist anywhere in the world for this zone" - not how many are currently standing inside its borders - so a cow that wanders off still counts against the cap, and it's what the leash radius pulls back. Untagged wild animals (already on the server, or spawned some other way) are never counted either way. Mobs in unloaded chunks are invisible to the server entirely, so one that wanders far enough to unload its own chunk will briefly stop counting/leashing until that chunk loads again.