ai_goal_follow

ai_goal_follow is an e0 available in all Source games. It makes the target NPCs follow another object or the player at a configurable distance. NPCs may react in some way if they can't path to their leader.

Note:NPCs do not intelligently follow their leader. They will simply walk or run depending on distance directly towards it. If the followers happen to block a path, they will not move out of the way and the leading NPC will eventually give up trying to path. (Depends on Formation.)

This entity is not in .

In code, it is represented by theCAI_FollowGoalclass, defined in theai_behavior_follow.cppfile.

ConVars/Commands

Cvar/Command	Parameters or default value	Descriptor	Effect
ai_debug_follow	0	0 disables, 1 enables	Tells when an NPC is having trouble following their leader. Requires developer 1. Does not function. [confirm]
ai_follow_use_points	1	0 disables, 1 enables	Todo: Effect description.
ai_follow_use_points_when_moving	1	0 disables, 1 enables	Todo: Effect description.

Keyvalues

Target Entity (goal) ([todo internal name (i)]) <string>

The name of the entity that the NPCs should follow. If this value is blank, NPCs will follow the player, if they are friendly towards them.

Formation (Formation) ([todo internal name (i)]) <choices>

How close to the target the NPCs should follow.

• 0: Close circle
• 1: Medium Circle
• 2: Wide circle
• 3: Sidekick
• 4: Vortigaunt

Todo: What exactly do 3 and 4 do?

AI_GoalEntity:

Actor(s) to affect (actor) <target_name_or_class>

The targetname or classname of any NPCs that will be included in this goal. Wildcards are supported.

Search Type (SearchType) <choices>

What the Actor(s) to affect keyvalue targets by.

• 0: Entity Name
• 1: Classname

Start Active (StartActive) <boolean>

Set if goal should be active immediately.

Inputs

OutsideTransition  (in all games since ) !FGD

Usually this is automatically done by a trigger_transition when the map changes, but it can be done manually as well. It sends the entity into a "dormant" state where it is disabled even though the entity may still think it is active. This is done in the case that the player decides to go back to a previous map, where the entity will then become non-dormant again and ensure NPCs continue to follow. Only available for the HL2 Episodes and Portal.

AI_GoalEntity:

Activate

Make the goal active if it wasn't already. NPCs will begin taking orders.

Deactivate

Make goal inactive.

UpdateActors  !FGD

Tell the goal entity to re-check Actor(s) to affect in case any disappeared, or any new NPCs spawned.^[confirm]