npc_rollermine is a point entity available in 
Half-Life 2, 
Half-Life 2: Episode One, 
Half-Life 2: Episode Two, and 
Half-Life 2: Deathmatch.
Basically an artificially intelligent prop_physics, the rollermine will roll itself at the player or at any NPC (excluding Combine NPCs). Upon hitting its target, the rollermine will electrify, damage what it is touching, and bounce off. They will attach themselves to Gordon's tau-equipped buggy from Half-Life 2, and they can be dropped by Combine dropships. If an explosion occurs near them, they will briefly fly into the air before disintegrating.
In Half-Life 2: Episode One, Alyx can reprogram rollermines to make them friendly to the player. This is done by using the outputs OnAlyxStartedInteraction and OnAlyxFinishedInteraction, and ai_relationship or the SetRelationship input.
Placement Tip:These rolling metal terrors can give the player quite a fright if they come up behind them and attack. They are manufactured and used by the Combine, so remember that when placing. A rollermine bounces pretty far after hurting a target, so be aware that they may accidentally fly into an area that could easily kill them or possibly cause them to be stuck.
Bug:In Half-Life 2, grabbing a rollermine with the supercharged gravity gun will not work, and results in the model cloning itself. [todo tested in?]Dedicated Console Variables
- sk_rollermine_shock <int>
- Approximation of the damage the rollermine deals. (Default: 10)
- sk_rollermine_stun_delay <int>
- How long the rollermine will remain dormant after zapping an enemy or being dropped with the Gravity Gun. (Default: 1)
- sk_rollermine_vehicle_intercept <int>
Todo: Add a description for this variable.
(Default: 1)
Keyvalues
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: HateD_FR: FearD_LI: LikeD_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.
|
- Start Buried
(startburied) <boolean>
- The rollermine will start partially hidden in the ground below it, and will jump out to give chase when an enemy gets near.
- Sight Distance
(uniformsightdist) <choices>
| Literal Value |
Description
|
| 0 |
Ignore distant targets not in a vehicle (default).
|
| 1 |
Equal visibility for all targets.
|
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.
|
- 65536: Friendly
- 131072: Use prop_physics collision rules (in all games since )
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: HateD_FR: FearD_LI: LikeD_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.
|
AlyxInteractable:
InteractivePowerDown (in all games since )- Shutdown this target.
TurnOn- Restore this rollermine to normal functionality.
TurnOff- Make this rollermine completely inert. Does not run AI and NPCs will ignore it.
PowerDown !FGD- Same as
InteractivePowerDown
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>- 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.
|
OnAlyxStartedInteraction- Fired when Alyx begins to interact with this entity.
OnAlyxFinishedInteraction- Fired when Alyx has finished interacting with this entity.
OnPhysGunPickup- Picked up with physgun (
!activator is the player.).
OnPhysGunDrop- Released by physgun (
!activator is the player.).
