Grillspett Flatten Earth

BepInEx mod for Valheim. Adds a hotkey that flattens a large area at once, raising low ground and lowering high ground to match the height under your cursor — unlike vanilla's Hoe "Level" tool, which only smooths a small radius per click and needs the ground pre-adjusted for big height differences.

Features

• One-press large-area flatten — hard-levels everywhere within the radius to the exact height under your cursor, both raising low spots and lowering high spots at once.
• Adjustable radius on the fly — Page Up / Page Down resize the area in 5m steps (up to 100m), with a chat message confirming the new size.
• Circle or square area shape, optional stamina cost, cooldown, and fully rebindable hotkeys — all configurable, no need to edit anything by hand.
• Multiplayer & dedicated-server safe — reuses the game's own terrain networking instead of a custom one, so edits stay correctly synced.
• Client-side only — nothing to install on a dedicated server.

How it works

While one of the Hoe's ground tools is selected (Raise Ground or Level Ground), press the hotkey (default: Home) instead of left-clicking. The mod reads the exact spot the game is already previewing (the same point vanilla would edit) and runs a hard terrain-level operation over a much larger radius in a single call.

This is deliberately different from vanilla's own tools, which turned out not to be a good fit for a big flatten: Raise Ground does a true level, but only within a 1.5m radius; Level Ground only smooths (blends toward the cursor height, with more effect near the center and almost none near the edge) and always repaints the ground as dirt. Reusing either as-is over a big radius would give a gentle dome/dip, not a flat plateau.

Instead, the mod temporarily forces the selected piece's own settings to a hard, paint-free level at the configured radius, places it through the game's normal piece-placement code, then immediately restores its settings so regular small-radius clicking is unaffected afterwards. This has to reuse the real selected piece rather than a custom object: Valheim's terrain networking never sends the actual radius/settings over the wire, only a hash of the piece's prefab name - the receiving side looks up its own copy of that exact, already-known piece to get the real settings, so a made-up piece fails that lookup outright. Reusing the real piece keeps the whole operation on the same networked path (TerrainOp/TerrainComp) vanilla pieces use, so ownership and syncing behave the same as a normal Hoe use.

Press Page Up / Page Down at any time to increase or decrease the flatten radius in 5m steps; the new radius is shown in a chat message.

On extreme cliffs a single press may not fully flatten the area (same as vanilla) - just press the hotkey again.

Configuration

Settings are written to BepInEx/config/grillspett.valheim.flattenearth.cfg after the first run:

Setting	Default	Description
FlattenKey	Home	Key that triggers the large flatten.
IncreaseRadiusKey	PageUp	Key that increases the flatten radius.
DecreaseRadiusKey	PageDown	Key that decreases the flatten radius.
Radius	20	Radius in meters (2-100).
RadiusStep	5	Radius change per press of the increase/decrease keys.
SquareArea	false	Flatten a square instead of a circle.
StaminaCost	0	Stamina per use; 0 disables the stamina check.
CooldownSeconds	0.3	Minimum time between uses.

Installing

Install through a mod manager (r2modman, Thunderstore Mod Manager, ...) like any other Thunderstore mod — it depends on BepInExPack_Valheim, which the manager installs automatically.

Installing manually instead: copy GrillspettFlattenEarth.dll into BepInEx/plugins/GrillspettFlattenEarth/. Either way, it only needs to go in your client profile — it just triggers the game's existing, unmodified terrain-networking RPCs (the same ones vanilla Hoe use already sends), so a dedicated server doesn't need the mod installed.

Building from source

Requires the .NET SDK (8.0+) and a local Valheim install (for its managed assemblies — referenced read-only at compile time, never modified).

dotnet build -c Release

The build auto-detects Valheim at C:\Program Files (x86)\Steam\steamapps\common\Valheim. If yours is elsewhere, set the VALHEIM_INSTALL_DIR environment variable to your install's root folder before building.

Output: bin\Release\net472\GrillspettFlattenEarth.dll

Optional: set OUTPUT_MOD_DIR to a BepInEx\plugins\... folder (e.g. an r2modman profile) and the build will copy the DLL there automatically:

$env:OUTPUT_MOD_DIR = "C:\Users\<you>\AppData\Roaming\r2modmanPlus-local\Valheim\profiles\<Profile>\BepInEx\plugins\GrillspettFlattenEarth"
dotnet build -c Release