npc_barnacle

Class hierarchy
CNPC_Barnacle ↳CAI_BaseNPC ↳CBaseCombatCharacter ↳CBaseFlex ↳CBaseAnimatingOverlay ↳CBaseAnimating ↳CBaseEntity
`npc_barnacle.cpp`

npc_barnacle is a point entity available in Half-Life 2, Half-Life 2: Episode One, Half-Life 2: Episode Two, Half-Life 2: Deathmatch, and Black Mesa. It is a stationary, ceiling-mounted 'fishing' monster that tries to eat anything its tongue touches. Barnacles were originally devised in Half-Life as a simple way to limit movement in levels, and their function remains relatively the same in Half-Life 2.

Placement Tip:Most players will prefer not to get caught by a barnacle, and prefer avoiding it altogether, so unless it would be part of a puzzle, you might want to provide a way to get past the barnacle without killing it.

Note:Some keyvalues, spawnflags, effect flags, inputs, or outputs might not affect an NPC, based on the functionality and coding of the NPC.

Warning:You must build structures from player clip similar to those in the picture, otherwise if barnacle grabs player - player may get stuck and barnacle will eventually release him. In

Black Mesa this case cause to a very severe breakdown of barnacle.


(click to view enlarged images) An example from d1_canals_02. With player clip. Without player clip. Black Mesa bug example in bm_c1a4b.

Note:Initially, barnacle can only grab and eat only chosen in game code NPCs. Can be customized using relationships.

Keyvalues

Rest Distance (RestDist) <float>: Distance above the ground that the tongue should lie when the barnacle is at rest

BaseNPC keyvalues
CBaseCombatCharacter: Relationship `(Relationship)` `<string>` !FGD <string\|targetname or classname> <string\|disposition> <int\|rank> Changes whether this entity likes or dislikes certain other things. Used like the `ai_relationship` entity, with this entity as the subject. Values for `disposition` are: `D_HT`: Hate `D_FR`: Fear `D_LI`: Like `D_NU`: Neutral Physics Impact Damage Scale `(physdamagescale)` `<float>` Multiplier for damage amount when this entity is hit by a physics object. With a value of 0 the entity will take no damage from physics. CAI_BaseNPC: Target Path Corner `(target)` `<targetname>` The `path_corner` that this NPC will move to after spawning. Squad Name `(squadname)` `<string>` NPCs that are in the same squad (i.e., have matching squad names) will share information about enemies and will take turns attacking and covering each other. Hint Group `(hintgroup)` `<string>` Hint groups are used by NPCs to restrict their hint-node searching to a subset of the map's hint nodes. Only hint nodes with matching hint group names will be considered by this NPC. Hint Limit Nav `(hintlimiting)` `<boolean>` Limits NPC to using specified hint group for navigation requests. Does not limit local navigation. Sleep State `(sleepstate)` `<choices>` Holds the NPC in stasis until specified condition. See also `Wake Radius` and `Wake Squad`. 0: None 1: Waiting for threat 2: Waiting for PVS 3: Waiting for input, ignore PVS 4: Auto PVS 5: Auto PVS after PVS Wake Radius `(wakeradius)` `<float>` Auto-wake if player comes within this distance. Wake Squad `(wakesquad)` `<boolean>` Wake all of the NPCs squadmates if the NPC is woken. Enemy Filter `(enemyfilter)` `<targetname>` Filter entity to test targets against. Ignore unseen enemies `(ignoreunseenenemies)` `<boolean>` Prefers visible enemies, regardless of distance or relationship priority. DamageFilter: Damage Filter `(damagefilter)` `<targetname>` Name of the `filter_damage_type` entity that controls which entities can damage us.

Flags

BaseNPC flags
Wait Till Seen `: [1]` Prevents this NPC from seeing (or being seen) until it enters a player's viewcone. Gag `: [2]` Won't make IDLE sounds until it's angry. *Fall to ground (unchecked means teleport* to ground) `: [4]` Drop Healthkit `: [8]` Causes this NPC to drop an `item_healthvial` upon dying. Efficient `: [16]` Don't acquire enemies or avoid obstacles Wait For Script `: [128]` Forces this NPC to "wait" in an idle state until it finishes playing a `scripted_sequence`. Long Visibility/Shoot `: [256]` By default, increases a NPC's sight range to `6,000` units and allows it to attack from anywhere within that distance. Fade Corpse `: [512]` Think outside PVS `: [1024]` Allows this NPC to run its regular AI outside of any player's PVS. Template NPC `: [2048]` Marks this NPC as a template for entities like `npc_template_maker`. The NPC will not spawn on its own. This is not needed for `point_template`. Do Alternate collision for this NPC (player avoidance) `: [4096]` Note:This flag is disabled in episodic for player companions, because the `StartScripting` input does this. Don't drop weapons `: [8192]` Ignore player push** `: [16384]` (in all games since ) Entity won't give way to player.

Cheap death : [65536]

Don't puke gibs.

Bug:Doesn't work in

Black Mesa

[todo tested in?]

Ambush Mode : [131072]

Don't start with tongue down.

Tongue will not penetate water : [262144] (only in )

Barnacle's tongue will not penetrate water if this flag used.

Don't spawn human skull on death : [524288] (only in )

Barnacle will not spawn human skull on death if this flag used.

Bug:Doesn't work. [todo tested in?]

Inputs

DropTongue <void>: Drop tongue towards the ground. Use in conjunction with Ambush Mode spawnflag.

SetDropTongueSpeed <integer>: Set Drop Tongue speed.

LetGo <void>: Let go of anything I am holding.

TongueTipUpdated <void> (only in )

BaseNPC inputs
CAI_BaseNPC: `ActivateSpeedModifier` !FGD `DisableSpeedModifier` !FGD `Break` Smash into pieces. If this is not possible, disappear. `BecomeRagdoll` (in all games since ) Remove itself and instantly become a ragdoll with zero force (just go limp). OnDeath, etc. outputs will NOT be fired. `ForceInteractionWithNPC <string> <string>` (in all games since ) Force the NPC to use a dynamic interaction with another NPC. Syntax is `<targetname> <dynamic interaction>`. `ForgetEntity` `<targetname>` Clears out the NPC's knowledge of a named entity. `UpdateEnemyMemory` (in all games since ) Update (or create) this NPC's memory of of the given entity. `GagEnable` `GagDisable` Gagged NPCs won't speak (or moan, caw, etc.) unless made to be a choreographed scene. `HolsterWeapon` (in all games since ) `UnholsterWeapon` (in all games since ) Force the NPC to holster or unholster their weapon. Ignored if the NPC is scripting or if the NPC doesn't use weapons. `HolsterAndDestroyWeapon` (in all games since ) Same as `HolsterWeapon`, except the weapon is destroyed once it has been concealed. `IgnoreDangerSounds` `<float>` Ignore danger sounds for the specified number of seconds. `InsideTransition` !FGD `OutsideTransition` !FGD `SetBodyGroup` `<integer>` HACK: Sets this NPC's body group (from 0–n). `SetEnemyFilter` `<string>` `SetHealth` `<integer>` Set the NPC's health. `SetMaxLookDistance` `<float>` (only in ) Sets the maximum look distance for the NPC. Defaults are 2048 and 6000 for long range NPCs. `SetRelationship <string\|targetname or classname> <string\|disposition> <int\|rank>` Changes whether this NPC likes or dislikes certain others. Used like the `ai_relationship` entity, with this NPC as the subject. Values for `disposition` are: `D_HT`: Hate `D_FR`: Fear `D_LI`: Like `D_NU`: Neutral `SetSquad` `<string>` Change the name of this NPC's squad. Leaving the parameter blank will remove the NPC from any existing squad. `StartScripting` `StopScripting` Enter/exit scripting state, where NPCs ignore a variety of stimulus that would make them break out of their scripts. They ignore danger sounds, ignore `+Use`, don't idle speak or respond to other NPCs' idle speech, and so on. `Wake` Wakes up the NPC if it is sleeping. CBaseCombatCharacter: `KilledNPC` !FGD Tells the entity it killed something. Despite the name, this can include a player. This input will be automatically sent by the victim when they die. `physdamagescale` `<float>` Scales damage energy when this character is hit by a physics object. With a value of 0 the NPC will take no damage from physics. DamageFilter: `SetDamageFilter` `<string>` Sets the entity to use as damage filter. Pass in an empty string (no parameter) to clear the damage filter.

Outputs

OnGrab <void>

OnRelease <void>: Fired when I attach/detach my tongue to/from something.

BaseNPC Outputs
`OnDamaged` Fired when this NPC takes damage (`!activator` is the damage inflictor). `OnDamagedByPlayer` Fired when this NPC is hurt by a player (`!activator` is the attacker or vehicle driver [if friendly fire]). `OnDamagedByPlayerSquad` Fired when this NPC is hurt by a player OR by one of the player's squadmates (`!activator` is the attacker or vehicle driver [if friendly fire]). `OnDeath` Fired when this NPC is killed (`!activator` is the killer). `OnDenyCommanderUse` Fired when this NPC has refused to join the player's squad. `OnForcedInteractionAborted` Fired when the NPC aborts a forced interaction for some reason (target NPC died, couldn't be pathed to, etc.). `OnForcedInteractionStarted` Fired when the NPC starts a forced interaction. `OnForcedInteractionFinished` "NPCs in actbusies can no longer perform dynamic interactions." Todo: What does this mean? `OnHalfHealth` Fired when this NPC reaches half of its maximum health. `OnHearCombat` Fired when this NPC hears combat sounds. `OnHearPlayer` Fired when this NPC hears the player. `OnHearWorld` Fired when this NPC hears a sound (other than combat or the player). `OnFoundEnemy` `<targetname>` Fired when this NPC establishes line of sight to its enemy. `OnLostEnemy` Fired when this NPC loses its enemy. Usually due to the enemy being killed/removed, or because this NPC has selected a newer, more dangerous enemy. `OnLostEnemyLOS` Fired when this NPC loses line of sight to its enemy. `OnFoundPlayer` `<targetname>` Fired when this NPC establishes line of sight to its enemy, and that enemy is a player. `OnLostPlayer` Fired when this NPC loses its enemy, and that enemy was a player. Usually due to the enemy being killed/removed, or because this NPC has selected a newer, more dangerous enemy. `OnLostPlayerLOS` Fired when this NPC loses line of sight to its enemy, and that enemy is a player. `OnSleep` Fired when this NPC enters a sleep state. `OnWake` Fired when this NPC comes out of a sleep state.

Dedicated Console Variables

Cvar/Command	Parameters or default value	Descriptor	Effect
`sk_barnacle_health`	`35`	int	Barnacle spawn health.
`npc_barnacle_swallow`		bool	Enable prototype swallow code. This makes the ragdolled yummy play the `ACT_GESTURE_BARNACLE_STRANGLE` activity. Cut in Black Mesa.
`sk_barnacle_357_dmg_scale (only in )`	`1`	float	Magnum damage scale.
`sk_barnacle_blunt_dmg_scale (only in )`	`1`	float	Blunt damage scale.
`sk_barnacle_buckshot_dmg_scale (only in )`	`1`	float	Buckshot damage scale.
`sk_barnacle_bullet_dmg_scale (only in )`	`1`	float	Bullet damage scale.

Bugs/Limitations

All

Tongue ignores objects with "$contents grate" and brush entities

Tongue will go throught objects that use $contents with grate value. Tongue will not be able to pull objects, it will grab and drop them immediately, with player it will do this endless until player go away (example).

The same will happen with brush entities, with the exception of func_physbox and func_physbox_multiplayer. func_detail and func_ladder are world brushes, so they are unaffected by this bug.

Clear example with func_brush.

Confirm:Might affect all CONTENTS_GRATE entities, such as brushes with %CompilePassBullets.

Grab itown gibs

Barnacle grab itown gibs (which appear after barnacle ate its enemy), fixed in Portal 2: Community Edition.

Half-Life 2 and Portal

Some NPCs becomes invisible

Some NPCs becomes invisible if barnacle eat them.

Some NPCs cause crash

Eating or grabbing of npc_combine_camera, npc_advisor, npc_rollermine, npc_portal_turret_floor or npc_poisonzombie will cause game crash.

Confirm:Is there more NPCs that cause crash if barnacle eating or grabbing them ?

Portal

Rocket turret create broken ragdoll

In Portal if barnacle grab npc_rocket_turret - npc_rocket_turret turns into a broken ragdoll, which has very broken physics.

Workaround:Fix the model or make barnacle friendly to npc_rocket_turret.

An example in d1_canals_01a.

Barnacle's gibs doesn't go through portals on spawn

Barnacle's gibs doesn't go through portals because of gibs use [4] : Debris spawnflag, with this flag physics objects use simple physics on spawn that doesn't allow them to go through portals.

An example in d1_canals_01a.

Barnacle's blood doesn't go through portals

If you'll kill barnacle that placed above linked portal - the blood decal will not be teleported.

An example in d1_canals_01a.
An example in d1_canals_01a.

Black Mesa: Definitive Edition

Note:Most of this issues are not available in

Black Mesa: Source.

Broken behavior if player stuck when barnacle pull player

Instead of player release, in Black Mesa this case cause to a very severe breakdown of barnacle. Not in Black Mesa 2012 (Mod).

Bug example in bm_c1a4b.

Tongue attaching is broken

In Black Mesa tongue attaching to player center for most cases, this is why it passes through player's camera.

An example bm_c1a4b.

`TongueTipUpdated` input every 0.01 seconds

In Black Mesa this NPC spams TongueTipUpdated input every 0.01 seconds.

Pulling is broken

Sometimes it may not pull player for a few seconds, and then suddenly and quickly pull player. Not in Black Mesa 2012 (Mod).

Grabbed NPCs disappear if barnacle die

If kill barnacle who has grabbed an enemy - the enemy's body will instantly disappear, unlike Half-Life 2 and Black Mesa 2012 (Mod) version.

Eats whole zombie

Barnacle eats whole zombie, in Half-Life 2 and Black Mesa 2012 (Mod) barnacle eats only headcrab and than drop zombie body. This does not depend on the type of zombie, it works with any zombie type.