Chest Snapping

Lets chests and other containers use Valheim's built-in snap system, the same way walls and floors do.

While placing a chest, press Q / E to cycle through its snap points. The normal message in the middle of the screen shows which one is active (for example Snapping: Bottom Front Left). Nothing about input or messages is re-implemented: vanilla already does the cycling and the message for any piece that has snap points. This mod just gives chests snap points.

Client-side only. Other players and servers do not need it.

Install

Requires BepInEx (BepInExPack_Valheim) and Jötunn. A mod manager such as Gale installs Jötunn for you.

Install with a mod manager, or put ChestSnapping.dll in BepInEx/plugins (Jötunn needs to be installed as well).

Snap points (cycle order)

#	Name
1-4	Bottom Front Left, Bottom Front Right, Bottom Back Left, Bottom Back Right
5-8	Top Front Left, Top Front Right, Top Back Left, Top Back Right
9-14	Bottom Center, Top Center, Back Center, Front Center, Left Center, Right Center

Points are placed on the chest's real collider bounds, so chests snap flush against each other. Front is the chest's local +Z and Right is +X, from the chest's own point of view. Names are localizable (English is provided, other languages fall back to English).

How to use it: pick a point on the chest you are holding (for example Bottom Back Right), aim near a snap point on another piece (another chest's corner or face center, or a wall/floor corner), and it locks on within vanilla's snap range (0.5 m). Rotation still matters: match the other chest's rotation with the normal rotate controls so the faces line up.

Built-in chests: piece_chest_wood, piece_chest, piece_chest_private, piece_chest_blackmetal.

Modded chests (or future vanilla chests)

No recompile needed. Use either way:

Console (F5)

Command	What it does
chestsnap_list [filter]	Lists every buildable container prefab and whether it has snap points.
chestsnap_add <prefab>	Adds a prefab. Saved to the config, existing chests update immediately.
chestsnap_remove <prefab>	Takes a prefab you added back off the list.

Config file BepInEx/config/com.kydldev.ChestSnapping.cfg

• ExtraPrefabs: comma-separated prefab names.
• ExcludedPrefabs: prefabs that should not get snap points (also works for the built-in ones).
• AutoDetectContainers (default off): every buildable piece with a Container on its root (ships and carts excluded) gets snap points automatically. Good for big modpacks, use ExcludedPrefabs for anything it catches that you do not want.

Prefab names are not case-sensitive.

Adjusting the snap points

Some modded chests have an oversized invisible collider or an off-center model, which puts the snap points in the wrong place. Each chest can be tuned separately. All distances are in meters along the chest's own axes (+X right, +Y up, +Z front). Both 0.05 and 0,05 are accepted in the console.

Command	What it does
chestsnap_show [on|off]	Draws a sphere on every snap point (yellow = corners, cyan = face centers). Session only.
chestsnap_info <prefab>	Prints the measured box, the current adjustments and where each of the 14 points ends up.
chestsnap_shift <prefab> x y z	Moves all points together.
chestsnap_grow <prefab> x y z	Adds to the box's half-size per axis. 0.05 makes the box 10 cm bigger on that axis, negative values shrink it.
chestsnap_point <prefab> <point> x y z	Offsets a single point. <point> is 1-14 (the Q/E order) or a name such as top_front_left.
chestsnap_reset <prefab> [point]	Clears the adjustments of a chest, or of just one point.

Setting a value to 0 0 0 clears it. Changes apply to chests that are already standing, and are saved in the config.

Example for a chest whose collider is 10 cm too wide and deep:

chestsnap_list crate
chestsnap_add MyMod_Crate
chestsnap_show on
chestsnap_grow MyMod_Crate -0.05 0 -0.05
chestsnap_point MyMod_Crate top_center 0 0.02 0
chestsnap_show off

The adjustments are stored in the PrefabAdjustments config entry and can be edited by hand. Entries are separated by ;:

MyMod_Crate: shift=0,0.05,0 grow=-0.05,0,-0.05 p9=0,0.02,0; OtherChest: grow=0.1,0,0

Numbers always use . as the decimal separator in the config file, whatever language your system uses.

Building

1. Put the contents of References.zip in a References folder next to ChestSnapping.csproj.
2. dotnet build -c Release (optional: -p:PluginsDir="<Valheim>\BepInEx\plugins" copies the dll there for you)

If the compiler complains about a missing Unity module, copy that dll from valheim_Data/Managed into References.

How it works

Vanilla snapping (Player.FindClosestSnapPoints / Piece.GetSnapPoints) looks for direct children of a Piece tagged snappoint. A Harmony postfix on Piece.Awake adds 14 such children to matching chests, for placed chests and for the placement ghost. Q/E (m_manualSnapPoint) and the $msg_snapping message are vanilla code and untouched.

Known limitations

• Prefab bounds come from non-trigger colliders (mesh bounds as a fallback). A chest with an oversized invisible collider gets oversized snap points. Use chestsnap_grow to fix that.
• Vanilla only snaps the ghost's points to other pieces' snap points, not to terrain.
• Debug spheres from chestsnap_show are depth-tested, so parts of them can be hidden inside the chest model.