Migrating Creatures

What it does: creatures leave home. Wolves come down from the mountains into the Black Forest, boar herds drift out of the Meadows, a band of greydwarfs wanders into the fields, lox roam across the Plains. They travel the world on foot, day and night, whether anyone is near them or not, so what you meet depends on where it is now, not only on where you are. Nothing announces it: no message, no marker. You find out when a lone wolf is standing at the edge of your meadow.

The biome is no longer the whole story.

Version 0.1.0. Travelling groups, routes, herds and the safety rules are in, tested in single player. Not yet tried in multiplayer or on a dedicated server.

Features

Most travellers are alone. A group is a lone animal most of the time, sometimes a pack of two to five, and only rarely a herd. A herd is something you remember seeing, not a weekly event.
They go somewhere. Each group gets a route across the land from one biome to another, winding round deep water, cliffs and your bases. Some legs it walks with purpose, near-straight and steady; on others it ranges, wandering around its line and stopping at the water's edge or on open ground. Now and then a group settles somewhere for a day or two before moving on, and when it reaches the end of its route it stays there until it moves on for good.
The world keeps moving when you are away. Far from players a group is only a position on the map, so a dozen of them cost almost nothing. When you come within 120 m it becomes real creatures; when everyone is 180 m away it goes back to being a position and carries on.
A fight is for keeps. A creature that turns on you (or on anything else) leaves its group for good and stays where it is: it never vanishes because you backed off, and it keeps its wounds like any creature.
Nothing is reset. While a group is out of sight its members keep their health and stars, so a group that took damage some other way is still hurt when it comes back into view.
Kept fair:
- routes never pass within 60 m of a player ward, so a migration does not walk through your base while you are away;
- migrants never target or damage buildings;
- at most one star by default;
- at most 12 groups in the world and 8 creatures in a group;
- by default, wolf and lox routes keep out of the Meadows.
Vanilla leaves them alone. Migrants do not despawn at dawn, do not count toward a biome's own spawn limits (the forest still spawns its own creatures), and are not pulled back to a spawn point.

The migration table

BepInEx/config/marc.valheim.migratingcreatures.table.txt, written on first run. One migration per line:

Default	From	To	Size
Wolf	Mountain	Black Forest (never through the Meadows)	1-5
Boar	Meadows	Black Forest	2-8
Greydwarf	Black Forest	Meadows	1-5
Lox	Plains	Plains (never into the Meadows)	1-6

Add any creature you like. mc_reload in the console re-reads it.

Config

BepInEx/config/marc.valheim.migratingcreatures.cfg, also in Configuration Manager (F1): group budget, how often groups start, group size weights, lifetimes, the materialise and dematerialise distances, travel modes, route rules, ward distance and the star cap.

Console (F5)

Command	What it does
`mc_status`	Version, groups, counters, hooks
`mc_list`	Every group: creature, size, state, position, distance, route progress, health (host only)
`mc_spawn [creature] [count]`	Starts a group placed for you now (host only)
`mc_goto <group> [metres]`	Teleports you onto a group's route ahead of it (host only)
`mc_route <group>`	Lists a group's waypoints (host only)
`mc_regen <group>`	Gives a group a fresh route from where it is (host only)
`mc_near`	Real migrants within 200 m
`mc_clear`	Removes every group and its creatures (host only)

Multiplayer

Install on every client and on the server. The server runs the travelling groups; each client runs the herds it is near.

Coming later

Signs of a passing herd (tracks in mud and snow, distant sounds, wildlife fleeing ahead of it), travelling groups leaving kills behind for The Dead Remain's scavengers, seasons, and routes along coasts and across shallows.

Install

Install with r2modman / Thunderstore Mod Manager, or drop MigratingCreatures.dll into BepInEx/plugins/MigratingCreatures/. For multiplayer, put it on the server too.