AI Category

The AI category contains the artificial intelligence nodes in Range Node Core. They cover everything from primitive movement behaviors to a complete modular system with perception, state management, navigation, and combat.

Two Approaches

Prefab approach — Enemy AI

A single Enemy AI node that encapsulates all logic: detection, patrol, chase, cover, attack, flee, and death. Best for quick prototyping or simple enemies.

Modular approach — Enemy System

Eleven specialized nodes that can be combined and replaced independently. Each node publishes ai_* variables that others read via getattr. The execution order is predefined by execution_order.

[OnUpdate]
    │
    ├── [Enemy Perception]       execution_order=40
    ├── [Damage Receiver]        execution_order=42
    ├── [AI State Machine]       execution_order=50
    ├── [Enemy Decision]         execution_order=51  (branch)
    ├── [Navigation Pathfinder]  execution_order=52
    ├── [Navigation Follow Path] execution_order=54
    ├── [Enemy Movement]         execution_order=55
    ├── [Enemy Rotation]         execution_order=56
    ├── [Enemy Combat]           execution_order=58
    ├── [Enemy Animation]        execution_order=60
    └── [Enemy Hit Flash]        execution_order=62

Primitive movement nodes

Seek, Flee, Patrol, and Wander are standalone nodes that don't depend on the modular system. They can be used alone or combined with BTCondition/BT nodes.

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ai_* variable contract

The ai_* variables are attributes on self (the Python component). They are read with getattr(self, 'ai_*', default) to avoid errors if the source node isn't in the scene.

Variable	Owner (WRITES)	Type	Description
ai_can_see	Enemy Perception	bool	Target visible this frame
ai_has_line_of_sight	Enemy Perception	bool	Unobstructed raycast to target
ai_dist	Enemy Perception	float	XY distance to target
ai_target	Enemy Perception	KX_GameObject|None	Target object reference
ai_target_pos	Enemy Perception	Vector|None	Target position if visible
ai_last_seen_pos	Enemy Perception	Vector|None	Last known position (persists)
ai_hp	Damage Receiver	float	Current HP
ai_hp_max	Damage Receiver	float	Maximum HP
ai_is_dead	Damage Receiver	bool	True when HP ≤ 0
ai_took_damage	Damage Receiver	bool	True the frame damage arrived
ai_recent_damage	Damage Receiver	bool	Alias for ai_took_damage
ai_state	AI State Machine	str	Current SM state
ai_prev_state	AI State Machine	str	Previous state
ai_state_time	AI State Machine	float	Seconds in current state
ai_alert_level	AI State Machine	float	0–1 for HUD/shader use
ai_attack_requested	AI State Machine	bool	True when state == ATTACK
ai_reload_requested	AI State Machine	bool	True when no ammo and not DEAD
ai_move_target	AI State Machine / Navigation Follow Path	Vector|None	Navigation destination
ai_in_attack_range	Enemy Combat	bool	Distance ≤ Attack Range
ai_is_moving	Enemy Movement	bool	Speed > 0.1
ai_nav_path	Navigation Pathfinder	list[Vector]	Current BFS path
ai_nav_index	Navigation Pathfinder / Follow Path	int	Current waypoint index
ai_reached_destination	Navigation Follow Path	bool	Path completed

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Damage channels (globalDict)

Channel	Written by	Read by
_dmg_<name>	Enemy Combat, Player Hitscan	Damage Receiver
_ai_dmg_<name>	Enemy AI (melee/ranged)	Enemy AI (internal)
_ai_dmg_src_<name>	Enemy AI (knockback)	Enemy AI (internal)

Important: The _dmg_* and _ai_dmg_* channels are separate. The modular system uses _dmg_*; the Enemy AI prefab uses _ai_dmg_* for its internal system.

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Nodes in this category

Primitive movement

Node	Type	Description
Seek	Exec	Chase a target with smooth arrival braking
Flee	Exec	Flee from a target until safe radius
Patrol	Exec	Patrol between 2–8 waypoints
Wander	Exec	Move in a periodically random direction

Detection

Node	Type	Description
Distance Check	Branch (Near/Far)	Branch by distance to target
Line Of Sight	Branch (Visible/Hidden)	Raycast line-of-sight check

Modular system

Node	Exec Order	Description
Enemy Perception	40	FOV + raycast + memory
Damage Receiver	42	HP and damage channel
AI State Machine	50	State machine IDLE→DEAD
Enemy Decision	51	Branch by ai_can_see
Navigation Pathfinder	52	BFS over waypoints
Navigation Follow Path	54	Follow path, stuck detection
Enemy Movement	55	Smoothed movement
Enemy Rotation	56	Smooth rotation toward target
Enemy Combat	58	Attack with cooldown
Enemy Animation	60	State-driven animations
Enemy Hit Flash	62	Color flash on damage

Prefab

Node	Description
Enemy AI	All-in-one: states, detection, movement, combat, animations