Merm Fx

Based on game build 714014 | Last updated: 2026-03-06

Overview

merm_fx defines two prefabs used for merm-related visual and mechanical effects: the lunarmerm_thorns_fx effect (an expanding damage field) and the merm_soil_marker (a temporary blocker). The thorns effect is typically attached to a merm and expands its radius over time, damaging non-ally entities within range while respecting PvP rules and leader relationships. It relies heavily on the updatelooper, combat, and follower components for execution and targeting.

Usage example

-- To spawn the thorns effect attached to an owner (e.g., a merm)
local fx = SpawnPrefab("lunarmerm_thorns_fx")
if fx ~= nil and fx.components.updatelooper then
    fx:SetFXOwner(merm_character)
end

-- The thorns will automatically expand, deal damage, and remove themselves
-- when radius reaches MAXRANGE (3 units)

Dependencies & tags

Components used: updatelooper, combat, follower Tags added: FX, thorny, NOBLOCK, merm_soil_blocker Tags checked (via HasTag/HasDebuff): player, merm, INLIMBO, notarget, noattack, flight, invisible, wall, playerghost, player

Properties

Property	Type	Default Value	Description
damage	number	TUNING[damage]	Damage dealt per update cycle (e.g., from TUNING.MERM_LUNAR_THORN_DAMAGE)
range	number	0.75	Current radius of effect; increases by 0.75 per update
ignore	table	{}	Map of entity instances to ignore (prevents repeated hits per frame)
canhitplayers	boolean	true	Whether the effect can damage players; set based on owner tag and PvP settings
owner	Entity or nil	nil	Entity that owns the effect; used for targeting and damage attribution
spdmg	nil	nil	Special damage type (never assigned in source — unused)

Main functions

SetFXOwner(inst, owner)

• Description: Attaches the effect to a specific entity (the owner), positions the FX at the owner’s location, sets PvP validity, and excludes the owner from damage. Enables bloom effect if owner has the wurt_merm_planar debuff.
• Parameters:
  • inst (Entity) — the FX entity instance.
  • owner (Entity) — the entity that will own this effect.
• Returns: Nothing.

OnUpdateThorns(inst)

• Description: Called each frame via updatelooper to expand the effect radius and damage eligible targets within range. Handles leader-based alliance checks, PvP logic, and ignores entities after first hit. Stops updating when range >= MAXRANGE.
• Parameters:
  • inst (Entity) — the FX entity instance.
• Returns: Nothing.
• Error states:
  • No-op if owner is invalid and inst.owner is not reset.
  • Does not damage targets already in inst.ignore.
  • Does not damage if target is not visible, invalid, or has a blocking tag.

Events & listeners

• Listens to: animover — triggers inst.Remove to clean up the FX when animation completes.
• Pushes: None.