Offspring Portal

Automate your breeding pens. Offspring Portal teleports tamed juveniles and breedable eggs from your breeder area to distant maturing pens the moment they wander into range — keeping vanilla population caps from stalling production.

Press E on juveniles to toggle follow/stay — useful for leading piglets and wolf cubs through portals or into pens before they grow up.

Build a portal, name it, configure it once, and let the mod handle the logistics. Species lists are built automatically from tamed adults near your breeder portals — no need to manually register mod creatures.

Offspring portals are for animal automation only — players cannot travel through them. Compatible with XPortal (offspring portals are excluded from XPortal's travel list).

Current version: 0.3.5

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Support & feedback

Bug reports, feature requests, and questions:

• Team Extreme Discord — setup help, example farms, and updates (use your Offspring Portal channel)
• GitHub Issues — Offspring Portal

When reporting a problem, include your mod version, single-player or multiplayer, and other portal-related mods (e.g. XPortal).

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Features

• Custom offspring portal — Hammer build piece (20 Fine Wood, 10 Greydwarf Eyes, 2 Surtling Cores)
• Five portal roles — Breeder, Maturing, Farm, Egg Collector, and Cull
• Dynamic species discovery — Maturing, Farm, and Egg Collector dropdowns are built from tamed breedable adults near breeder portals (deduped per species)
• Mod creature support — Any creature that passes the breedable criteria below is discovered automatically via prefab name
• Automatic juvenile routing — Breeder portals send tamed juveniles to matching maturing pens
• Automatic egg routing — Breeder portals send laid eggs to Egg Collector or maturing pens (see dual vs single-purpose below)
• Mate draw — Fed, ready adults near breeder portals nudge toward same-species mates within breeding range
• Round-robin — Multiple maturing/farm/cull/egg-collector portals of the same type share load automatically
• Optional adult routing — Maturing portals can forward grown adults to Farm, Cull, or leave them (None)
• One shared Cull yard — A single Cull portal handles every species
• Portal config UI — Press E on a portal to set name, type, species, and destination
• Custom portal names — Shown on hover for easy identification
• Juvenile follow command — Press E on tamed juveniles to toggle Follow / Stay (configurable)
• Breeding cap warning — Hover warning when a maturing pen sits inside vanilla breeding cap radius
• Distant pen support — Teleports wait for unloaded zones before giving up
• Multiplayer support — Routing runs on host; all players need the mod installed
• XPortal compatible — Offspring portals excluded from XPortal's travel list
• Players cannot travel — Offspring portals are for animals only, not player teleportation
• Configurable — Scan range, mate draw, discovery radius, intervals, cooldowns, and more via offspringportal.mod.cfg

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At a glance

Portal type	What it does
Breeder	Sends juveniles and eggs out; discovers nearby breedable species; optional mate draw
Maturing	Receives juveniles and single-purpose eggs; optionally forwards grown adults
Egg Collector	Receives dual-purpose eggs only (e.g. hen eggs for recipes + hatching)
Farm	Receives adults routed back from maturing pens (by species)
Cull	One shared yard — receives adults marked for slaughter

Juvenile follow: With EnableFollowCommand on (default), look at a tamed juvenile and press E to toggle Follow / Stay.

Minimum setup: 2 portals (Breeder + Maturing). Farm, Egg Collector, and Cull are optional.

Build cost: 20 Fine Wood · 10 Greydwarf Eyes · 2 Surtling Cores

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Dynamic species discovery

Breeder portals scan for tamed breedable adults within discovery range and register each species once for the whole world (four boar pens still produce one Boar entry).

That list drives the Receives dropdown on Maturing and Farm portals, and the egg-type dropdown on Egg Collector portals. All is always available as a catch-all.

Discovery refreshes every breeder scan, so placing a new mod creature at a breeder portal adds it to the lists without editing config files.

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Dual-purpose vs single-purpose eggs

When a tamed egg layer lays an egg near a Breeder portal, routing depends on whether the egg item is also a crafting ingredient.

Egg type	How the mod decides	Where it goes
Dual-purpose	The egg item appears in at least one enabled ObjectDB crafting recipe (e.g. hen egg used in cooking)	Egg Collector portal for that egg type → if none, Maturing (species match → All)
Single-purpose	The egg only hatches — it is not used in any enabled recipe (e.g. asksvin egg)	Maturing portal (species match → All) — same path as live-born juveniles

Examples

• Hen (dual-purpose): Route recipe eggs to an Egg Collector → Egg Hen pen (chest auto-collect, sorting, etc.). Eggs that miss the collector fall back to maturing pens for hatching. You can heat a subset at the maturing destination.
• Asksvin (single-purpose): Eggs go straight to Maturing → Asksvin or All — no Egg Collector needed.

Egg Collector portal

• Set Type: Egg Collector and choose the egg type (shown as Egg Hen, Egg Penguin, etc.).
• Only dual-purpose egg layers appear in this dropdown.
• Do not use Maturing for dual-purpose egg collection — use Egg Collector so recipe eggs and hatch eggs can be split across destinations.

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For mod creators — what counts as breedable?

Offspring Portal does not use a hardcoded species list. It discovers creatures at runtime from vanilla breeding components. If your modded animal works with the rules below, it should appear in portal dropdowns and route correctly without a patch from us.

Requirements (all paths)

1. The creature must be tamed.
2. It must be within discovery scan range of a placed Breeder portal (default: max of breeder scan range and mate draw range).
3. The adult must have a Procreation component with m_offspring pointing at a valid prefab.

Live-birth species (boar, wolf, lox, asksvin calf, etc.)

The offspring prefab chain must be:

Procreation.m_offspring → Character (juvenile)
                              └── Growup component
                                    └── m_grownPrefab (or m_altGrownPrefabs) → adult Character

If that chain resolves, the species is registered under the adult prefab name (vanilla names like Boar, Wolf, Lox, Chicken for hens, or your mod's prefab name).

Egg-laying species (hen, penguin, mod egg layers)

The offspring prefab chain must be:

Procreation.m_offspring → egg prefab
                              └── EggGrow component
                                    └── m_grownPrefab → hatchling Character
                                                          └── Growup → adult Character

• Dual-purpose if the egg ItemDrop is referenced by any enabled crafting recipe → eligible for Egg Collector routing.
• Single-purpose if the egg is hatch-only → routes like a juvenile to Maturing.

Fallback registration

If the full juvenile/egg chain cannot be resolved but the tamed adult has Procreation and is not itself a juvenile (Growup absent), the mod still registers the species using the adult's normalized prefab name. This helps mod creatures whose prefab references are incomplete in the asset bundle.

Species keys and matching

• Keys come from normalized prefab names (clone suffixes stripped).
• Vanilla aliases are mapped where known (e.g. prefab names containing Hen → Chicken / UI label Hen).
• Portal Receives matching is case-insensitive; All accepts every discovered species.
• Mod creatures typically appear under their adult prefab name in dropdowns.

Checklist for mod authors

Component	Live birth	Egg layer
Procreation on tamed adult	✓	✓
Procreation.m_offspring set	✓	✓
Juvenile Character + Growup	✓	—
Egg prefab + EggGrow	—	✓
Hatchling Growup → adult	✓	✓
Egg in crafting recipe (optional)	—	dual-purpose only

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Mate draw (breeder portals)

When EnableMateDraw is on (default), breeder portals periodically scan for fed, ready-to-breed tamed adults and nudge them toward the nearest eligible same-species mate until they are within vanilla breeding range.

Mate draw applies when the animal:

• Has Procreation and ReadyForProcreation() is true
• Is not hungry, not alerted, not following the player
• Is an adult (no Growup on self)
• Has a resolvable species key

Mate draw stops when animals are already within partner range, become pregnant, or no longer qualify.

Defaults: 15 m draw range, 1.5 s scan interval, 2.5 m stop distance (capped below vanilla partner range).

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How juveniles and eggs move

Breeder Portal                         Maturing Portal
  (at breeding pen)    ── juvenile ──►  (at grow-up pen)
                       ── single-use egg ──►

Breeder Portal                         Egg Collector Portal
  (at breeding pen)    ── dual-purpose egg ──►  (collection / chest pen)
                       └── fallback ──► Maturing (if no collector)

1. Place a portal at your breeding area → configure as Breeder
2. Place a portal at your grow-up area → configure as Maturing → set Receives to a species (or All)
3. For dual-purpose egg layers, add an Egg Collector portal → set Receives to Egg Hen (or the matching egg type)
4. When a tamed juvenile or egg enters the breeder portal's scan radius, it teleports to the next matching destination (round-robin if you have several)

Hover any portal to see its Name, role, and warnings.

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Maturing pen destinations (adults)

Each Maturing portal has one Receives species (or All) and one Destination for adults that grow up on that portal.

Destination	Behavior
None	Adults stay on the maturing pen (default)
Farm	Adults teleport to a Farm portal matching their species (or All)
Cull	Adults teleport to your Cull yard — one Cull portal serves every species

If Destination is Farm or Cull but no receiver portal exists yet, you'll see a yellow hover warning and adults won't teleport until you place one.

Mixed species, different outcomes: Use one Maturing portal per species when adults need different destinations. Place them in the same building if you like — the Breeder sends each juvenile to the Maturing portal whose Receives matches that species.

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Example setups

Starter — 2 portals (juveniles only)

Portal	Type	Receives	Destination	Name example
Breeding area	Breeder	—	—	Boar Farm
Grow-up pen	Maturing	Boar	None	Boar Maturing

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Hen farm — dual-purpose eggs

Portal	Type	Receives	Destination	Name example
Coop	Breeder	—	—	Hen Coop
Recipe egg pen	Egg Collector	Egg Hen	—	Egg Collection
Hatch pen	Maturing	Hen	None	Chick Maturing

Hen eggs try the Egg Collector first; overflow or unmatched eggs fall back to Maturing. Chicks grow up on the maturing pen.

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Boar production + cull automation

Portal	Type	Receives	Destination	Name example
Breeding pen	Breeder	—	—	Boar Farm
Grow-up pen	Maturing	Boar	Cull	Boar Maturing
Slaughter area	Cull	—	—	Boar Cull Yard

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Cull boars, keep wolves on-site

Portal	Type	Receives	Destination	Name example
Main breeder	Breeder	—	—	Mixed Farm
Grow-up pen	Maturing	Boar	Cull	Boar Maturing
Grow-up pen	Maturing	Wolf	None	Wolf Maturing
Cull yard	Cull	—	—	Cull Yard

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Return adults to the farm

Portal	Type	Receives	Destination	Name example
Breeder	Breeder	—	—	Boar Farm
Distant grow-up	Maturing	Boar	Farm	Boar Maturing
Farm holding	Farm	Boar	—	Boar Holding

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Multiple maturing pens (round-robin)

Portal	Type	Receives
Breeder	Breeder	—
North pen	Maturing	Boar
South pen	Maturing	Boar

Same species + same role = round-robin.

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Config UI (press E on a portal)

Field	Breeder	Maturing	Egg Collector	Farm	Cull
Name	✓	✓	✓	✓	✓
Type	✓	✓	✓	✓	✓
Receives	All juveniles (fixed)	✓ (discovered species)	✓ (dual-purpose eggs)	✓ (discovered species)	All adults (fixed)
Destination	—	None / Farm / Cull	—	—	—

Receives lists are populated from species discovered at breeder portals. Until discovery runs, vanilla fallback options may appear.

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Config file

After first launch, edit:

BepInEx/config/offspringportal.mod.cfg

General

Setting	Default	Description
BreederScanRange	10	Scan radius (meters) around breeder portals for juveniles and eggs
BreederScanIntervalSec	0.5	How often breeders scan
MaturingAdultScanIntervalSec	30	How often maturing pens scan for adults to forward
TeleportCooldownSec	2	Per-animal/per-egg cooldown after teleport
DistantTeleportTimeoutSec	15	Wait for distant zones to load before giving up
AllowRetransport	false	Allow the same animal or egg to teleport again
EnableCapWarning	true	Warn when a maturing pen is inside breeding cap radius
EnableFollowCommand	true	Press E on tamed juveniles to toggle follow/stay

Breeding

Setting	Default	Description
DiscoveryScanRange	0	Radius for discovering breedable species at breeders (0 = max of breeder scan and mate draw range)
EnableMateDraw	true	Nudge ready adults toward mates near breeder portals
MateDrawRange	15	Max distance between mates before nudging (meters)
MateDrawIntervalSec	1.5	How often breeders scan for mate draw
MateDrawStopDistance	2.5	How close mates move before stopping

Restart Valheim after changing config values.

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Multiplayer

Install on server/host and every client. Everyone needs the mod to see the custom portal piece, open the config UI, and get correct hover text. BepInEx and Jotunn are required on all sides.

Teleport logic runs on the server/host.

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Requirements

Installed automatically with most mod managers:

• BepInEx Pack
• Jotunn

Manual install

1. Install BepInEx and Jotunn.
2. Place OffspringPortal.dll in BepInEx/plugins/.
3. Launch once to generate the config file.

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Tips

• Name your portals — hover text shows custom names
• Press E on juveniles to toggle follow/stay when moving them into breeder range
• Destination: None is the safe default until you're ready for Farm or Cull automation
• One Cull portal can serve your entire world
• Egg Collector is for dual-purpose eggs only — single-purpose layers use Maturing
• One Maturing portal = one species rule for mixed keep/cull setups
• Keep maturing pens outside vanilla breeding cap radius when possible
• Players cannot travel through offspring portals

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Source code

Public repository: github.com/cdjensen99-sudo/Offspring_Portal

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Credits

By HW