ScalerCore

A scaling library for R.E.P.O. modders. Handles the hard parts of scaling game objects -- physics, audio, animation, colliders, NavMesh, multiplayer sync -- so you don't have to.

If you're building a mod that changes the size of things (shrink rays, growth potions, whatever), ScalerCore gives you a clean API and takes care of the edge cases.

This is a library, not a standalone mod. End users don't need to interact with it directly. If you're a player, you probably got here because a mod like ShrinkerGun: COMPRESSOR depends on it.

For modders building size-changing mechanics. If you're looking for a shrink ray, check out ShrinkerGun: COMPRESSOR which is built on ScalerCore.

Installation

Reference ScalerCore.dll in your project. Add a hard dependency in your plugin:

[BepInDependency("Vippy.ScalerCore", BepInDependency.DependencyFlags.HardDependency)]

ScalerCore automatically attaches ScaleController components to all enemies, players, valuables, items, carts, and doors at runtime via Harmony patches. You don't need to add them yourself.

Quick Start

using ScalerCore;

// Shrink with default options (40% scale)
ScaleManager.Apply(targetGameObject);

// Shrink with custom options
var opts = ScaleOptions.Default;
opts.Factor = 0.5f;
opts.Duration = 60f;
ScaleManager.Apply(targetGameObject, opts);

// Restore with animation
ScaleManager.Restore(targetGameObject);

// Restore instantly (for bonk/damage reactions)
ScaleManager.RestoreImmediate(targetGameObject);

// Check state
bool tiny = ScaleManager.IsScaled(targetGameObject);

ScaleManager.Apply is host-authoritative. The host calls it, and RPCs propagate to all clients automatically. Late-joining players receive the current state on connect.

How It Works

ScalerCore attaches a ScaleController (a MonoBehaviourPunCallbacks) to every enemy, player, valuable, item, and door. On the first scale operation, the controller:

1. Resolves a handler via ScaleHandlerRegistry based on what the object is
2. Applies the target scale with a smooth animation (back-out easing for players, linear interpolation for objects)
3. Adjusts physics (mass, grab force, collider radius), audio pitch, and NavMesh speed
4. Syncs state to all clients via Photon RPCs
5. Force-applies the target scale every LateUpdate to fight game code that resets localScale

Built-in handlers cover enemies, players, valuables, items, carts, and doors.

Custom Handlers

Implement IScaleHandler and register it with a predicate:

using ScalerCore;
using ScalerCore.Handlers;

public class MyBossHandler : IScaleHandler
{
    public void Setup(ScaleController ctrl)
    {
        // Cache components, set ScaleTarget if the visual root
        // is different from the physics root
    }

    public void OnScale(ScaleController ctrl)
    {
        // Called when the object is scaled down
    }

    public void OnRestore(ScaleController ctrl, bool isBonk)
    {
        // Called when restored. isBonk = true means instant (damage),
        // false means animated (timer/gun toggle)
    }

    public void OnUpdate(ScaleController ctrl)    { }
    public void OnLateUpdate(ScaleController ctrl) { }
    public void OnDestroy(ScaleController ctrl)    { }
}

Register it at plugin startup. Use priority > 0 to override built-in handlers:

ScaleHandlerRegistry.Register(
    new MyBossHandler(),
    go => go.GetComponentInParent<EnemyParent>()?.name.Contains("MyBoss") == true,
    priority: 10
);

The registry resolves handlers by checking predicates in descending priority order. First match wins.

API Reference

ScaleManager (static)

ScaleController (MonoBehaviourPunCallbacks)

Attached automatically to game objects. Key public members:

IScaleHandler

public interface IScaleHandler
{
    void Setup(ScaleController ctrl);
    void OnScale(ScaleController ctrl);
    void OnRestore(ScaleController ctrl, bool isBonk);
    void OnUpdate(ScaleController ctrl);
    void OnLateUpdate(ScaleController ctrl);
    void OnDestroy(ScaleController ctrl);
}

ScaleHandlerRegistry (static)

ScaleOptions

Each Apply() call takes a ScaleOptions struct. Use ScaleOptions.Default as a starting point and override what you need.

ScaleTargets

Flags enum for filtering what Apply() affects:

var opts = ScaleOptions.Default;
opts.AllowedTargets = ScaleTargets.Enemies | ScaleTargets.Valuables;
ScaleManager.Apply(target, opts); // skips players and items

Configuration

ScalerCore is a pure library with no user-facing config. All scaling behavior (factor, speed, duration, etc.) is controlled per-call via ScaleOptions -- consuming mods expose whatever settings make sense for them.

What ScalerCore Handles

For enemies:

• Visual mesh + physics rigidbody scaled separately (EnemyParent is never scaled)
• NavMesh agent speed and radius
• Grab force reduced to zero (instantly grabbable when shrunken)
• Follow force scaled so grabbed enemies don't fight back
• Damage output reduced
• Knockback force reduced
• Bonk restore on taking damage (with immunity window)

For players:

• Camera offset, crouch/crawl positions, vision targets
• Collision capsules (stand, crouch, stand-check)
• Grab strength, range, throw strength
• Movement speed
• FOV adjustment
• Voice chat pitch
• Footstep sound pitch
• Animation speed
• Enlarged pupils (big cute eyes)
• Pause menu avatar scaled to match
• Near clip plane adjusted

For valuables:

• Mass scaled and clamped
• Extraction zone detection box scaled
• Brief indestructibility after shrinking (prevents fall damage from collider resize)
• Value-drop detection triggers bonk restore
• ForceGrabPoint disabled to prevent grab oscillation

For items:

• Effect fields auto-scaled (explosion size, orb radius, damage)
• Inventory system compatibility (yields during equip/unequip)
• ForceGrabPoint handling

For non-pocketable items (carts, cart cannon, cart laser, tracker):

• Become pocketable while shrunken (press inventory key to stash)
• Shrunken players can't pocket shrunken items — if you get shrunk while holding one, it drops
• Restoring removes the equip ability so full-size items stay on the ground

For all types:

• Audio pitch shifted on all Sound objects
• Smooth scale animation with force-apply in LateUpdate
• Multiplayer sync via Photon RPCs
• Late-join state sync
• Automatic cleanup on level change

Known Issues

• Loom (Shadow) arms don't scale proportionally when shrunken (IK solver conflict — cosmetic only, attack distance still scales)
• Some untested enemy types may float or clip into the ground while shrunken

Dependencies

• BepInEx 5 (5.4.2100+)

Reference Implementation

ShrinkerGun: COMPRESSOR is a shrink ray gun built on ScalerCore. Shows how to build ScaleOptions, call Apply, and handle per-target-type durations.

Changelog

0.4.4

Bug fixes

• Fixed non-host clients running Dispatch methods (DispatchShrink, DispatchExpand, DispatchExpandNow) — these are now gated behind a host/singleplayer check

0.4.3

New

• MapCollapse is now public — other mods call MapCollapse.OnMapHit() to trigger the collapse event
• ScaleController.ChallengeMode public property — implementations set this to enable challenge mode
• Runtime SemiIconMaker generation for pocketed items — no more embedded PNGs, works for any item

Bug fixes

• Fixed map collapse audio ignoring master volume (now routes through the game's SFX mixer group)
• Fixed map collapse alarm doubling when the truck had no unique sounds
• Fixed camera glitch effect not covering the full screen while shrunken
• Fixed shrunken players getting crushed too early during map collapse (raycast distances now scale with player size)
• Fixed pocketed item icons disappearing after level transitions
• Map collapse crush sequence reworked — FOV slam, heavy shake, vignette, and a brief hold before death

Improvements

• ScalerCore is now a pure library with no user-facing config entries
• ShrinkChallengeMode and MapCollapse config removed — implementations own their settings
• MapCollapseHitPatch removed — implementations provide their own hit detection
• Map collapse enemy speed toned down (1.3x base, up to 1.8x — was 2.5x to 6.5x)
• Map collapse no longer unshrinks everything when it starts
• Map collapse FOV narrows during collapse for a claustrophobic feel
• Embedded cart/cannon/laser icon PNGs replaced with runtime SemiIconMaker

0.4.2

Improvements

• Added MapCollapse config option (Auto/On/Off). You'll know it when you see it. Turn it on and shoot the map, go ahead, I dare you.
• No, Loom's arms still aren't fixed. I was busy with the super ultra important above feature for next year's april fools.
• Removed Herobrine

0.4.1

New

• Any non-pocketable item becomes pocketable while shrunken — carts, cart cannons, cart lasers, trackers. Press an inventory key to stash, shoot again to restore.
• Shrunken players can't pocket shrunken items. If you get shrunk while carrying one, it drops automatically.

Bug fixes

• Fixed shrunken players being able to wall-jump infinitely by touching walls
• Fixed Shrink Challenge mode not working on clients (inverted re-shrink was blocked by debug key gate)
• Fixed Shrink Challenge mode not working in singleplayer (was stuck waiting for voice chat)
• Fixed Shrink Challenge mode firing in the lobby instead of waiting for the level to load
• Fixed voice pitch not cleaning up when returning to lobby
• Fixed camera occasionally clipping through walls at shrunken size
• Pupil override priority and spring speed now match vanilla ranges
• Items now stay shrunken permanently until shot again (was 5 minutes)
• Enemy speed while shrunken is now 75% (was 65%)

Improvements

• Shrink Challenge mode config changes apply instantly in the lobby
• Shrunken items show as smaller dots on the map
• Smoother pupil transition when expressions end
• Embedded inventory icons for cart, cart cannon, and cart laser
• Logging cleaned up — only warnings and errors in the console
• InvertedMode synced to clients via RPC for proper multiplayer challenge mode

0.4.0

New

• Added SuppressValueDropExpand option to ScaleOptions — valuables won't expand on damage while scaled. For cart mods where items bump into each other constantly.
• Added PreserveMass option to ScaleOptions — rigidbody mass stays at its original value while scaled. For cart mods where items should weigh the same regardless of visual size.
• Added ScaleManager.ApplyIfNotScaled() — scales only if not already scaled, no-op otherwise. Safe to call every frame from continuous triggers.
• Added ScaleManager.GetController() — returns the ScaleController for a game object, resolving through PlayerShrinkLink.

Bug fixes

• Fixed shrunken objects appearing full-size on non-host clients. The RPC was only sending the target vector without ScaleOptions fields, so clients had all-zero options and the animation never ran. Also broke late-join sync.
• Fixed shrunken player mesh freezing in place on the host. AnimSpeedMultiplier wasn't synced to clients, so the client sent a zero-speed animation override back via RPC, killing the host's visual position interpolation.
• Fixed players reverting to full size when another player jumped or tumbled into them. Bonk expand now only triggers when health actually decreases, not on zero-damage contact.

0.3.0

New

• Shrink Challenge Mode: players start shrunken, guns temporarily grow you, damage shrinks you back
• Shooting an already-shrunken target with the same factor toggles it back
• Shooting an already-shrunken target with a different factor rescales it smoothly (no flash)

API changes

• ScaleManager.Apply() now takes a ScaleOptions struct — per-call config replaces global ShrinkConfig
• ScaleManager.Apply() without options uses ScaleOptions.Default
• Added ScaleTargets flags enum for filtering what object types can be scaled
• Added ScaleController.TargetType for mods to check what kind of object a controller manages
• Removed ShrinkConfig and ScaleFactor (replaced by ScaleOptions)
• Zero Factor/Speed in ScaleOptions falls back to defaults

Bug fixes

• Fixed players in tumble/object mode (Q) not being shrinkable by guns
• ScaleManager API now resolves PlayerShrinkLink when target GO doesn't have ScaleController directly
• Fixed Tricycle (Bella) trike mesh not scaling — rider shrank but the bike stayed full size
• Single doors now cleanly break off their hinges when shrunken instead of floating in place
• Birthday Boy's balloons now shrink along with him
• Enemies killed or despawned while shrunken no longer respawn at shrunken size
• HeartHugger mesh and collision now align properly when shrunken (including when tipped)
• HeartHugger gas pull distance scales with enemy size
• Loom attack distance scales with enemy size
• Fixed bonk expand not restoring visual scale on enemies with handler-owned scaling
• Replaced most reflection with direct publicizer access for better performance
• Fixed Loom (Shadow) NRE spam in EnemyShadow.HandLogic after unshrinking

0.2.0

Bug fixes

• Pupils no longer stay huge after unshrinking
• Animation speed resets properly on unshrink
• Grab range actually scales down while shrunken now
• Voice pitch no longer gets nuked by spewer/hourglass events
• Menu preview shows big pupils while shrunken
• Host now enforces grab stats for all shrunken players, not just local
• Remote players see big pupils in the shop
• Menu preview only shrinks for the shrunken player, not everyone
• Non-host sees their own big pupils in menu preview
• Non-host grab strength/range/throw restores properly after unshrinking
• Big pupils yield to expressions while shrunken (no more bleeding through eyelids)
• Cart pull distance no longer leaks the host's shrink state to other players
• Shrunken enemies deal scaled damage across the board (mace swings, tumble impacts, instakills)
• Enemies like Trudge whose mace has playerKill no longer instakill when shrunken
• Damage scaling works even when the HurtCollider doesn't have enemyHost set
• NavMesh agent radius scales with enemy size
• Fixed Chef, Mentalist, Reaper, Trudge, and Elsa sinking into the ground when shrunken
• Fixed Loom (Shadow) arms detaching from body when shrunken
• Fixed AnimTarget discovery walking up to Enable container on enemies with renderers on the Rigidbody (caused double-scaling on Hearthugger and Loom)
• Known: Hearthugger still has visual/grab misalignment when shrunken (cosmetic, gameplay unaffected)

Balance

• Grab strength less punishing (1.5x scale factor, capped at 100% when shrunk)
• Added MinimumStrength and MaximumStrength config options
• Grab range and throw scale directly with size (no mercy bonus)
• Enemy damage scales by shrink factor directly (was a flat 0.1x)
• Enemy bonk immunity down from 5s to 3s
• Items stay shrunk indefinitely (was 300s)

Improvements

• Menu avatar animates smoothly when shrinking/unshrinking instead of snapping
• Negative shrink durations from bad configs get clamped to 0
• Version auto-stamped from csproj via BuildInfo

Internal

• Assembly publicizer replaces all reflection in PlayerHandler
• ItemHandler uses standard GetField instead of AccessTools
• All enemy-to-player damage scaling lives in one patch now (KnockbackPatch)
• Deduplicated grab strength formula into GetGrabFactors helper
• Noisy item field logs downgraded to LogDebug
• Dropped REPOLib dependency (wasn't actually used)
• Updated Thunderstore description

0.1.0

Initial early access release.