npc_zombie

Source Engine

Source 2

GoldSrc

Half-Life: Source

Class hierarchy
CZombie ↳CAI_BlendingHost ↳CNPC_BaseZombie ↳CAI_BaseZombieBase ↳CBaseCombatCharacter ↳CBaseFlex ↳CBaseAnimatingOverlay ↳CBaseAnimating ↳CBaseEntity
npc_zombie.cpp

npc_zombie is a point entity available in Half-Life 2.

These "classic" zombies, being wonderfully slow and stupid, are best used in groups to swarm the player. While it is unlikely the player will view them as a real threat, they are a great way to add tension and benefit from working with other zombie types, such as the npc_fastzombie or the npc_poisonzombie. Some Ravenholm areas use as many as 4-5 zombies at a time.

When advancing upon the player, zombies will knock small physics props that are blocking them at the player, with surprising force.

If the zombie's host body is sufficiently damaged, the controlling npc_headcrab may detach and attack independently.

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

Dedicated Console Variables

Cvar/Command	Parameters or default value	Descriptor	Effect
sk_zombie_health	50	int	A zombie's spawn health
sk_zombie_dmg_one_slash	10	int	Zombie melee damage
sk_zombie_dmg_both_slash	25	int	Zombie melee damage (Not used.)

Note:The zombie will only deal the damage set in sk_zombie_dmg_one_slash for all of its attacks (even when using both hands). This may be due to a simple mistype in npc_BaseZombie.cpp that can easily be corrected.

Keyvalues

Name (targetname) <string>

The name that other entities refer to this entity by, via Inputs/Outputs or other keyvalues (e.g. parentname or target).
Also displayed in Hammer's 2D views and Entity Report.

See also:  Generic Keyvalues, Inputs and Outputs available to all entities

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.

Inputs

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

OnCrab (only in )

Fired when this NPC spawns a live headcrab. (!activator is the headcrab)

OnSwattedProp (only in )

Fired when this NPC swats a physics object, such as prop_physics or func_physbox. (!activator is the swatted object)

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.

Replace zombie blood with human blood

In src/game/server/hl2/npc_zombie.cpp, go to line 279.

#ifdef HL2_EPISODIC
       SetBloodColor ( BLOOD_COLOR_ZOMBIE );

Modify it to look like this:

#ifdef HL2_EPISODIC
       SetBloodColor ( BLOOD_COLOR_RED );

Remove headcrab from zombies

How to remove headcrab from zombies.

In src/game/server/hl2/npc_zombie.cpp look for void CZombie::Spawn( void ) then find this line.

m_fIsHeadless = false;

and simply change it to this

m_fIsHeadless = true;

Now open src/game/server/hl2/npc_BaseZombie.cpp and change the HeadcrabRelease_t CNPC_BaseZombie::ShouldReleaseHeadcrab( const CTakeDamageInfo &info, float flDamageThreshold ) section to look like this:

//-----------------------------------------------------------------------------
// Purpose: A zombie has taken damage. Determine whether he release his headcrab.
// Output : YES, IMMEDIATE, or SCHEDULED (see HeadcrabRelease_t)
//-----------------------------------------------------------------------------
HeadcrabRelease_t CNPC_BaseZombie::ShouldReleaseHeadcrab( const CTakeDamageInfo &info, float flDamageThreshold )
{
	return ( m_iHealth <= 0 && m_fIsTorso && IsChopped( info ) ) ? RELEASE_RAGDOLL_SLICED_OFF : RELEASE_NO;
}

Alternatively, if you are using Mapbase, replace the npc_zombie entity with a npc_zombie_custom entity and set "Headcrabless" to true

See also

• npc_poisonzombie
• npc_fastzombie
• npc_zombie_torso