Spawn Suppression Visualizer for Valheim

A small BepInEx mod that draws the enemy spawn suppression radius of your structures directly in the world, so you can see exactly where creatures can and cannot spawn around your base.

How spawn suppression works in Valheim

Valheim's SpawnSystem picks random points around players and runs each one through IsSpawnPointGood. One of those checks rejects any point that lies inside an EffectArea of type PlayerBase. Workbenches, forges, fires, wards and similar "base" pieces carry a PlayerBase area (typically a 20 m sphere). Anywhere those spheres cover, the natural spawner will not place a creature.

This mod does not guess or hard-code radii. It reads the live list of effect areas from the game (EffectArea.GetAllAreas()), takes the radius from each area's collider, and draws a ring on the ground for every area near you. Whatever the game uses, you see.

It can also draw NoMonsters areas (monster AI refuses to path into them) in a second colour.

Features

• Ground fill around you: green where creatures cannot spawn, red where they can. Gaps in your coverage show up instantly as red patches between the green.
• Terrain-hugging rings for every PlayerBase (green) and NoMonsters (blue) area in range.
• Optional centre post per area so you can tell which structure a ring belongs to.
• Toggle with a hotkey (default F7) or the console command spawnsupp [on|off|toggle].
• On-screen label with the number of areas currently drawn.
• Everything configurable through BepInEx config (colours, width, segments, height mode, max distance, refresh rate, enabled on start).
• Client-side only. Safe on a dedicated server (does nothing there) and does not touch gameplay: no spawn logic is modified.

Installation

1. Install BepInExPack Valheim.
2. Copy ValheimSpawnSupp.dll into <Valheim>/BepInEx/plugins/ValheimSpawnSupp/.
3. Start the game once. The config file appears at <Valheim>/BepInEx/config/f1shar.ValheimSpawnSupp.cfg.

Usage

• Press F7 (configurable) in a world to toggle the overlay.
• Or open the console (F5) and type spawnsupp, spawnsupp on, or spawnsupp off.
• Walk around your base: the overlay refreshes once a second by default, so freshly placed or destroyed pieces show up almost immediately.
• Red ground means a creature can spawn there. Place a workbench, campfire or ward so the green discs overlap until no red is left inside your walls.

Configuration

Section	Key	Default	Meaning
General	ToggleKey	F7	Hotkey to toggle the overlay.
General	EnabledOnStart	false	Show the overlay as soon as you enter a world.
Areas	ShowPlayerBase	true	Draw PlayerBase areas (the actual spawn suppression radius).
Areas	ShowNoMonsters	true	Draw NoMonsters areas.
Areas	PlayerBaseColor	green	Ring colour for PlayerBase areas.
Areas	NoMonstersColor	blue	Ring colour for NoMonsters areas.
Appearance	LineWidth	0.2	Ring width in metres.
Appearance	Segments	72	Vertices per ring.
Appearance	HeightOffset	0.3	Metres above the ground the ring floats.
Appearance	HeightMode	Terrain	Terrain, Solid (follow floors and rocks) or Flat.
Appearance	ShowCenterMarker	true	Draw a short post at each area's centre.
Ground fill	FillMode	Both	Both, Covered (green only), Uncovered (red only) or None.
Ground fill	CoveredFillColor	green	Tint where spawns are blocked.
Ground fill	UncoveredFillColor	red	Tint where spawns are possible.
Ground fill	FillOpacity	0.3	Strength of the tint, 0 to 1.
Ground fill	FillRadius	80	Metres around the player that get shaded.
Ground fill	FillCellSize	2	Grid spacing of the fill mesh in metres.
Ground fill	FillHeightOffset	0.35	Metres above the ground the fill floats.
Performance	MaxDistance	250	Only draw areas within this distance of the player. 0 = unlimited.
Performance	RefreshInterval	1	Seconds between overlay rebuilds.
Performance	ShowHudLabel	true	Show the "N area(s)" label while active.

Colours are RGBA with components from 0 to 1 and can be edited in the config file or with a config manager mod.

License

MIT. See LICENSE.