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Desiccant

Based on game build 714014 | Last updated: 2026-03-05

Overview​

desiccant is a prefab constructor that creates a drying item used to reduce wetness in the environment. It leverages the inventoryitemmoisture and moistureabsorbersource components to manage moisture absorption and drying behavior. The item updates its visual wetness prefix and emits sound effects in response to moisture changes, and integrates with the fire-melting system to disable drying while burning.

Usage example​

local inst = CreateEntity()
inst:AddTag("inventoryitemmoisture")
inst:AddComponent("inventoryitem")
inst:AddComponent("moistureabsorbersource")

inst.components.inventoryitemmoisture:SetExternallyControlled(true)
inst.components.inventoryitemmoisture:SetOnlyWetWhenSaturated(true)
inst.components.inventoryitemmoisture:SetOnMoistureDeltaCallback(my_callback)

local rate_fn = function(inst, rate) return TUNING.DESICCANT_DRY_RATE end
local apply_fn = function(inst, rate, dt) inst.components.inventoryitemmoisture:DoDelta(rate * dt) end
inst.components.moistureabsorbersource:SetGetDryingRateFn(rate_fn)
inst.components.moistureabsorbersource:SetApplyDryingFn(apply_fn)

Dependencies & tags​

Components used: inventoryitem, inventoryitemmoisture, moistureabsorbersource, inspectable
Tags added: meltable
Tags checked: inventoryitemmoisture, inventoryitem

Properties​

PropertyTypeDefault ValueDescription
_playsfxNetEventnet_event(GUID, "desiccant.playsfx")Networked event used to play sound effects on clients.
_isdampNetBoolnet_bool(GUID, "desiccant.isdamp", "isdampdirty")Networked boolean indicating whether the item is damp (0 < moisture < MAX_WETNESS).
_playsfx_thresholdnumbernilTracks moisture level at which last SFX was played; used for delta-based SFX triggering.

Main functions​

IsFull(inst)​

  • Description: Determines whether the item is fully saturated (wetness ≥ TUNING.MAX_WETNESS).
  • Parameters: inst (entity) - the entity instance with inventoryitemmoisture component.
  • Returns: true if fully wet, false otherwise.

GetRate(inst, rate)​

  • Description: Returns the drying rate when the item is not fully saturated; returns zero otherwise.
  • Parameters: inst (entity), rate (unused number).
  • Returns: TUNING.DESICCANT_DRY_RATE if not full, else 0.

ApplyDrying(inst, rate, dt)​

  • Description: Applies drying to the item's moisture level using the base drying rate and delta time.
  • Parameters: inst (entity), rate (unused number), dt (number) - time elapsed since last frame.
  • Returns: Nothing. Calls inventoryitemmoisture:DoDelta(rate * dt).

GetRate_Boosted(inst, rate)​

  • Description: Similar to GetRate, but uses the boosted drying rate for the desiccantboosted variant.
  • Parameters: inst (entity), rate (unused number).
  • Returns: TUNING.DESICCANTBOOSTED_DRY_RATE if not full, else 0.

ApplyDrying_Boosted(inst, rate, dt)​

  • Description: Applies drying using the boosted drying rate.
  • Parameters: inst (entity), rate (unused number), dt (number).
  • Returns: Nothing. Calls inventoryitemmoisture:DoDelta(rate * dt).

OnIsDampDirty(inst)​

  • Description: Updates the item's wetness prefix (wet_prefix, always_wet_prefix) based on damp/full status and triggers tooltip update if changed.
  • Parameters: inst (entity).
  • Returns: Nothing.
  • Error states: Sets wet_prefix to STRINGS.WET_PREFIX.GENERIC when dry; sets to DESICCANT when damp; DESICCANT_FULL when saturated.

OnMoistureDeltaCallback(inst, oldmoisture, newmoisture)​

  • Description: Responds to moisture changes by updating the _isdamp state, triggering tooltip update, and optionally playing sound effects when moisture changes cross the threshold.
  • Parameters: inst (entity), oldmoisture (number), newmoisture (number).
  • Returns: Nothing.

Events & listeners​

  • Listens to:
    firemelt - calls OnFireMelt to disable external moisture control (drying stops while burning).
    stopfiremelt - calls OnStopFireMelt to re-enable moisture control.
    onputininventory - calls OnStopFireMelt (ensures drying resumes when picked up after burning).
    desiccant.playsfx (client-only) - triggers OnPlaySFX to broadcast item_buff_changed.
    isdampdirty (client-only) - triggers OnIsDampDirty to update visuals and tooltips.
  • Pushes:
    inventoryitem_updatetooltip - fired when wetness prefix changes (inside OnIsDampDirty).
    item_buff_changed (via ThePlayer:PushEvent) when SFX triggers.