npc_helicopter

Template:Hl2 point A Combine helicopter, (also called a "Hunter-Chopper") armed with a machine gun and capable of dropping mines.

Entity description

Helicopter - click to enlarge.

The Helicopter Mine from Episode 2.

The mines are buoyant, and their timer only activates when they collide with the environment. In Episode 2 their detonation timer is delayed when picked up by the Gravity gun. Upon touching an NPC they detonate instantly. They can be dropped one at a time, or when triggered the helicopter can rush a target dropping a massive amount of mines.

• This is a flying NPC that uses info_node_air, info_node_air_hint or path_tracks for AI navigation.
• This NPC can follow Path_track entities as well.

Related Entities:

• npc_heli_avoidbox Is a brush entity that the helicopter will avoid.
• npc_heli_avoidsphere Is an entity that keeps helicopters out of a spherical area.
• npc_heli_nobomb This entity suppresses helicopter bombing
• helicopter_bomb This entity is a bomb that the helicopter can drop

Tip:Use info_target_helicopter_crash entities to suggest spectacular crashing points for defeated helicopters.

Placement Tip:Hunter-Choppers are used mainly in the Half-Life 2 series as chase vehicles, hence the name.

Placement Tip:Helicopter battles require the player to be very mobile, and have some cover available to them. Just one can present a great challenge, so like striders use them sparingly.

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

Dedicated Console Variables:

sk_helicopter_health <int>

Helicopter Spawn Health (Default: 5600).

sk_helicopter_firingcone <float>

The angle in degrees of the cone in which the shots will be fired.

sk_helicopter_burstcount <int>

How many shot bursts to fire after charging up. Bigger number = longer firing.

sk_helicopter_roundsperburst <int>

How many shots to fire in a single burst.

sk_helicopter_grenadedamage <float>

The amount of damage the helicopter grenade deals.

sk_helicopter_grenaderadius <float>

The damage radius of the helicopter grenade.

sk_helicopter_grenadeforce <float>

The physics force that the helicopter grenade exerts.

sk_npc_dmg_helicopter_to_plr <float>

Damage helicopter shots deal to the player.

Used in ammotype "HelicopterGun".

sk_npc_dmg_helicopter <float>

Damage helicopter shots deal to everything but the player.

Used in ammotype "HelicopterGun".

sk_helicopter_drone_speed <float>

How fast does the zapper drone move?

g_helicopter_chargetime <float>

How much time we have to wait (on average) between the time we start hearing the charging sound + the chopper fires.

g_helicopter_bullrush_distance <float>

Todo: Add a description for this variable.

g_helicopter_bullrush_bomb_enemy_distance <float>

Todo: Add a description for this variable.

g_helicopter_bullrush_bomb_time <float>

Todo: Add a description for this variable.

g_helicopter_idletime <float>

Todo: Add a description for this variable.

g_helicopter_maxfiringdist <float>

Todo: Add a description for this variable.

g_helicopter_bullrush_bomb_speed <float>

Todo: Add a description for this variable.

g_helicopter_bullrush_shoot_height <float>

Todo: Add a description for this variable.

g_helicopter_bullrush_mega_bomb_health <float>

Todo: Add a description for this variable.

Keyvalues

BaseHelicopter:

Initial Speed (InitialSpeed) <string>

The speed that the entity should try to reach as soon as it spawns

Target path_track (target) <targetname>

The name of a path_track that this NPC will fly to after spawning.

InitialSpeed ([todo internal name (i)]) <float>

GracePeriod ([todo internal name (i)]) <float>

Time in seconds the helicopter has to see the player before he starts shooting.

PatrolSpeed ([todo internal name (i)]) <float>

Speed at which the helicopter moves if he has no enemy.

Flags

Wait Till Seen : [1]

Gag (No IDLE sounds until angry) : [2]

Fall to ground (unchecked means *teleport* to ground) : [4]

Drop Healthkit : [8]

Efficient - Don't acquire enemies or avoid obstacles : [16]

No Rotorwash : [32]

Await Input : [64]

Wait For Script : [128]

Long Visibility/Shoot : [256]

Fade Corpse : [512]

Think outside PVS : [1024]

Template NPC (used by npc_maker, will not spawn) : [2048]

Do Alternate collision for this NPC (player avoidance) : [4096]

Don't drop weapons : [8192]

• 65536 : Loud rotor wash sound
• 131072 : Electrical drone
• 262144 : Helicopter lights
• 524288 : Ignore avoid spheres+boxes
• 1048576 : More aggressive attacks

Inputs

BaseHelicopter

MoveTopSpeed The helicopter will immediately move at top speed toward its current goal, or in its current orientation if it's on top of its goal. MoveSpecifiedSpeed <floatRedirectInput/float> The helicopter will immediately move at the specified speed (you provide this as parameter override in units per second) towards its current goal. ChangePathCorner <targetnameRedirectInput/string> Tell the helicopter to move to a path corner on a new path. SelfDestruct Self Destruct. Activate Activate. Use to wake up a helicopter that spawned with the 'Await Input' spawnflag on. SetTrack <targetnameRedirectInput/string> Set a track for the helicopter to adhere to. The helicopter will do nothing if it's on the same path, and will move to the closest point on the specified track if it's on a different path. FlyToSpecificTrackViaPath <targetnameRedirectInput/string> The helicopter will first fly to the closest point on the path if it's on a different path. Then it'll fly along the path to the specified track point. FlyToPathTrack <targetnameRedirectInput/string> The helicopter will fly to the given path_track. StartPatrol Start patrolling back and forth along the current track. StopPatrol Stop patrolling back and forth along the track. This will cause the helicopter to come to rest at the track which he's currently flying toward. ChooseFarthestPathPoint When tracking an enemy, choose the point on the path furthest from the enemy, but still in firing range. ChooseNearestPathPoint When tracking an enemy, choose the point on the path nearest from the enemy. StartBreakableMovement The helicopter is now allowed to disobey direct commands to go to particular points if it senses an enemy. It will move to the closest point (or farthest point, if ChooseFarthestPathPoint is used), on the path if it senses an enemy. StopBreakableMovement The helicopter can no longer disobey direct commands. It will continue to fly along it's patrol path or to it's specified target even if it senses an enemy. EnableRotorSound Starts the chopper's rotors making noise (normal behaviour) DisableRotorSound Stops the noise made by the rotors EnableRotorWash Makes the chopper exert a force on physics objects underneath its rotor, and produce a wind pattern on any water (normal behaviour) DisableRotorWash Turns off the forces and wind pattern SetAngles  !FGD InputStartLeading  !FGD InputStopLeading  !FGD GunOn Allows the chopper to use its gun (normal behaviour) GunOff Prevents the chopper from using its gun MissileOn Starts the chopper firing rockets Bug:Non-functional.  [todo tested in ?] MissileOff Stops the chopper firing rockets Bug:Non-functional.  [todo tested in ?]

GunOn

GunOff

MissileOn

MissileOff

EnableRotorWash

DisableRotorWash

EnableRotorSound

DisableRotorSound

StartBombingVehicle

Starts the chopper leading enemy vehicles and dropping bombs on them.

StartTrailingVehicle

Starts the chopper trailing enemy vehicles and shooting at them.

StartDefaultBehavior

Starts the chopper in the mode where he always stops at nav points instead of stopping anywhere in between nav points.

StartAlwaysLeadingVehicle

Starts the chopper *always* leading enemy vehicles (regardless of how they are moving w/respect to the path) and dropping bombs on them. This mode is different from StartBombingVehicle in that it never uses the machine gun.

StartSprinkleBehavior

Starts the chopper dropping bombs randomly + shooting at the player.

StartBullrushBehavior

Starts the chopper bullrushing the player.

SetHealthFraction <floatRedirectInput/float>

Sets the chopper health as a percentage of max health.

EnableDeadlyShooting

Starts the chopper being deadly to on-foot players.

DisableDeadlyShooting

Stops the chopper being deadly to on-foot players.

StartNormalShooting

The chopper will fire in short bursts. Good for on-foot experiences.

StartLongCycleShooting

The chopper fires in long bursts.

StartContinuousShooting

The chopper fires continuously.

ResetIdleTime

Allows the helicopter to fire immediately if he's not in the middle of charging or firing.

SetAngles <anglesRedirectInput/Vector>

Instantly snaps the orientation of the helicopter.

DropBomb

Immediately drops a bomb based on normal bomb dropping rules.

DropBombStraightDown

Immediately drops a bomb directly downwards.

DropBombAtTarget <targetnameRedirectInput/string>

Immediately drops a bomb directly at the target destination, but only if the player isn't right there.

DropBombAtTargetAlways <targetnameRedirectInput/string>

Immediately drops a bomb directly at the target destination, no matter whether it's fair or not.

DropBombDelay <floatRedirectInput/float>

Add a delay before the next bomb is dropped.

BecomeIndestructible

Makes the helicopter take no more damage.

DisablePathVisibilityTests

When the helicopter moves, he will not check for visibility from the path_track to the enemy to cull out path_tracks.

EnablePathVisibilityTests

When the helicopter moves, he will only move to path_tracks that have line-of-sight to the enemy.

Outputs

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*RedirectOutput/ehandle> 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*RedirectOutput/ehandle> 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.

OnHealthChanged <integerRedirectInput/integer>

Fires when the helicopter health changes. The integer is the percentage of health the chopper has from 0-100.