View source for Ai relationship

{{lang|Ai relationship}}
[[File:ai_relationship.png|left]]
{{base point|ai_relationship}} It sets a relationship type between two parties. These parties can be an [[NPC]], an NPC class, or the player(s). Any object descending from {{ent|CBaseCombatCharacter}} can have relationships, most notably NPCs and players.{{clr}}

Dispositions:<!--This order matches the enum in code, although D_ER has been moved to the bottom-->
{| class="wikitable"
|-
! Name || Description
|-
| Hate (D_HT) || Considers the target an enemy. Most NPCs will attack if possible, although NPCs that cannot attack may flee instead.
|-
| Fear (D_FR) || Tries to avoid/flee from the target. Behavior varies across NPCs. Most NPCs will just run to cover out of the target's sight while NPCs with ranged weapons may run away while shooting at the feared enemy. {{bugfix|The trace code used by melee damage doesn't detect D_FR entities and therefore NPCs can't use melee attacks against them. (they may try, but they won't do any damage)|This can be fixed by going to <code>CTraceFilterMelee::ShouldHitEntity()</code> and replacing <code><nowiki>pBCC->IRelationType( pEntity ) == D_HT</nowiki></code> with <code><nowiki>pBCC->IRelationType( pEntity ) <= D_FR</nowiki></code>, which correctly accounts for both D_HT and D_FR.|code}}
|-
| Like (D_LI) || Considers the target a friend. NPCs will never intentionally attack these targets and NPCs with <code>bits_CAP_FRIENDLY_DMG_IMMUNE</code> (e.g. [[npc_citizen|citizens]]) will not take any damage from NPCs or players that have this disposition towards them. {{note|Only the disposition of the NPC that deals the damage is considered by <code>bits_CAP_FRIENDLY_DMG_IMMUNE</code>. If a citizen friendly to the player (citizen D_LI to the player) is attacked by a player that doesn't consider them friendly (player not D_LI to the citizen), they will take damage and may not retaliate without additional programming.}}
{{codenote|<code>bits_CAP_FRIENDLY_DMG_IMMUNE</code> can be added to a NPC with <code>AddCapabilities</code> and is usually appended in an NPC's <code>Spawn()</code> function, although it can be toggled at any time.}}
|-
| Neutral (D_NU) || Considers a target neutral. NPCs usually won't consider these targets at all, or at least not care about them as enemies or as allies. This is used for fauna like [[npc_crow|crows]]. {{tip|Making a <code>npc_citizen</code> neutral to the player ''(but not the other way around)'' is used to prevent them from joining the player's squad.}}
|-
| Error (D_ER) || This "error" disposition is used internally to determine if something went wrong in a relationship. Should not be used. NPC behavior mostly equivalent to neutral.{{confirm}}
|}

Not available in {{HLS}} {{css}} {{dods}} {{l4ds}} {{csgo}}.

{{note|While <code>ai_relationship</code> does not exist in {{game link|Half-Life: Source}}, the <code>SetRelationship</code> input works.}}

{{code class|CAI_Relationship|ai_relationship.cpp}}

==Flags==
*1: Notify subject of target's location
*2: Notify target of subject's location

==Keyvalues==
{{KV|Subject(s) (subject)|target_name_or_class|The [[targetname]] ''or'' [[classname]] of the NPCs whose disposition will change.}}
{{KV|Subject Class (subjectclass)|classname|since=AS|As above, for classnames only.}}
{{KV|Target(s) (target)|target_name_or_class|The targetname ''or'' class name of the NPCs about whom the subject(s) will change their disposition towards. {{tip|Use <code>!player</code> for the player.}}}}
{{KV|Target Class (targetclass)|classname|since=AS|As above, for classnames only.}}
{{KV|Disposition (disposition)|choices|The way the subject(s) should feel about the target(s)
:#Hate
:#Fear
:#Like
:#Neutral}}
{{KV|Radius for subject (radius)|float|Only NPCs within this distance of the entity will have their dispositions changed.}}
{{KV|Disposition Priority (rank)|int|How much the subject(s) should Like/Hate/Fear the target(s). Higher priority {{=}} stronger feeling.}}
{{KV|Start Active (StartActive)|bool|Apply this relationship as soon as the entity spawns?}}
{{KV|Reciprocal (Reciprocal)|bool|Make the new disposition apply to the targets as well as the subjects.}}
{{KV BaseEntity}}

==Inputs==
{{IO|ApplyRelationship|Applies relationship changes. This will change all subject entities' relationships to all target entities. {{note|Once you fire <code>ApplyRelationship</code>, the entity is on until you send a <code>RevertRelationship</code> or <code>RevertToDefaultRelationship</code> input. During the time any entities that spawn who match the subject or target names '''will''' be affected.}} {{warning|Unpredictable results may occur when two ai_relationship entities refer to the same set or subset of target or subject entities. This situation should be avoided.}}}}
{{IO|RevertRelationship|Reverts relationship changes to what the relationship of the first one was at the time the <code>ApplyRelationship</code> input was called (or when this ai_relationship was spawned if ''Start Active'' is set).}}
{{IO|RevertToDefaultRelationship|Reverts relationship changes to the entities' default relationships, completely returning control of affected relationships to the code.}}
{{I BaseEntity|prel4d=1}}

==Outputs==
{{O BaseEntity}}

==See also==
*[[List of default AI relationships]]

[[Category:AI]]