Prefab Hammer

Prefab Hammer is an advanced construction utility for Valheim. It allows players to capture custom build combinations (prefabs/blueprints) directly from their existing structures, name them, manage them in a catalog, and build them using standard resource calculations.

Features

Manual Component Selection: Aim at built pieces and press J to select them one-by-one with a pulsating green outline.
Exact Geometry Outlines: Selection highlights clone the piece's actual visual meshes, making the green transparent overlay conform precisely to floors, sloped roofs, beams, and custom shapes.
Name & Save Dialog: Press K to open the solid-colored popup manager, name your creation, and save it.
Prefab Library Catalog: View your blueprints in a scrollable list, delete them safely with confirm prompts, or open the catalog using Delete or Shift + K.
Batched Placement: Large blueprints are built in small batches across multiple frames — no freezes, even with 1000+ piece structures. Progress messages display during placement.
Undo Placement: Press Shift + U to open the Undo History tab and remove recently placed blueprints. Materials are refunded by dropping them at the original piece locations.
Structural Integrity: Placed structures correctly calculate stability after construction. Hover pieces with the hammer to see support colors.
Unequip Cleanup: Switching away from the Hammer automatically clears outlines and selections to prevent world clutter.
Radius Fallback: Pressing the save hotkey without selecting anything falls back to saving all pieces in a radius.
Chat Commands: Use /prefablist, /prefabsave, /prefabreload, and /prefabdelete.

Keybinds (Configurable)

J: Toggle manual piece selection (must hold Hammer).
K: Open save panel / Prefab Manager.
Delete or Shift + K: Open Library Catalog directly.
Shift + U: Open Undo History tab.

Installation

Prefab Hammer requires BepInEx to run.

Install BepInExPack Valheim.
Place PrefabHammer.dll into the BepInEx/plugins/ directory (or download directly via r2modman).

Configuration

You can customize the mod's behavior by editing BepInEx/config/com.prefabhammer.cfg (or using r2modman's Config Editor):

BuildCategory: The build menu category tab where your custom prefabs are loaded (default: Prefab). Can be set to vanilla tabs like Misc, Crafting, Building, or Furniture.
SaveHotkey: Hotkey to open the save panel (default: K).
SelectHotkey: Hotkey to toggle selecting pieces (default: J).
UndoHotkey: Hotkey to open the Undo History tab (default: U, used with the modifier key).
ModifierKey: Modifier key used in combination with hotkeys (default: LeftShift). Options: Shift, Control, Alt, LeftShift, RightShift, LeftControl, RightControl, LeftAlt, RightAlt, None.
DefaultRadius: Capture radius in meters for the fallback area save (default: 5.0).
PlacementBatchSize: Number of pieces placed per frame during batched building (default: 10). Lower values reduce stuttering on slower hardware.
MaxUndoHistory: How many recent placements are kept in the undo history (default: 5).

Features

Manual Component Selection: Aim at built pieces and press J to select them one-by-one with a pulsating green outline.

Exact Geometry Outlines: Selection highlights clone the piece's actual visual meshes, making the green transparent overlay conform precisely to floors, sloped roofs, beams, and custom shapes.

Name & Save Dialog: Press K to open the solid-colored popup manager, name your creation, and save it.

Prefab Library Catalog: View your blueprints in a scrollable list, delete them safely with confirm prompts, or open the catalog using Delete or Shift + K.

Batched Placement: Large blueprints are built in small batches across multiple frames — no freezes, even with 1000+ piece structures. Progress messages display during placement.

Undo Placement: Press Shift + U to open the Undo History tab and remove recently placed blueprints. Materials are refunded by dropping them at the original piece locations.

Structural Integrity: Placed structures correctly calculate stability after construction. Hover pieces with the hammer to see support colors.

Unequip Cleanup: Switching away from the Hammer automatically clears outlines and selections to prevent world clutter.

Radius Fallback: Pressing the save hotkey without selecting anything falls back to saving all pieces in a radius.

Chat Commands: Use /prefablist, /prefabsave, /prefabreload, and /prefabdelete.

Configuration

You can customize the mod's behavior by editing BepInEx/config/com.prefabhammer.cfg (or using r2modman's Config Editor):

BuildCategory: The build menu category tab where your custom prefabs are loaded (default: Prefab). Can be set to vanilla tabs like Misc, Crafting, Building, or Furniture.

SaveHotkey: Hotkey to open the save panel (default: K).

SelectHotkey: Hotkey to toggle selecting pieces (default: J).

UndoHotkey: Hotkey to open the Undo History tab (default: U, used with the modifier key).

ModifierKey: Modifier key used in combination with hotkeys (default: LeftShift). Options: Shift, Control, Alt, LeftShift, RightShift, LeftControl, RightControl, LeftAlt, RightAlt, None.

DefaultRadius: Capture radius in meters for the fallback area save (default: 5.0).

PlacementBatchSize: Number of pieces placed per frame during batched building (default: 10). Lower values reduce stuttering on slower hardware.

MaxUndoHistory: How many recent placements are kept in the undo history (default: 5).