How to detect if a stationary NPC is inside a Trigger?
I'm trying to figure out the best way to detect whether a NPC (one that never walks) is inside a trigger zone or not. (Sometimes that NPC will be teleport to other rooms so handling his position with variables would be more complicated.)
The setup: The player needs to pick up an object from a room, but only if the NPC is not in that room. I want to use a trigger placed inside the room to determine the NPC's presence.
What I understand so far: I know the logic I want to implement — I just need to set a variable based on whether the NPC is inside the trigger or not, and then check that variable before allowing the pickup action.
My question: Since the NPC doesn't walk, I can't rely on OnEnter/OnExit events firing during gameplay. I need to actively check the NPC's state at the moment the player tries to interact with the object.
I guess I need to use the action Object->Send Message to the trigger->Interact... BUT... should I use two separate trigger components — one for "NPC inside" and one for "NPC outside" — and call each independently?
Is there a cleaner way to handle this with a single trigger?
Any guidance would be greatly appreciated!
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Is this to say the Trigger spans the entire room, such that the position within the room is irrelevant?
A Trigger that covers the whole scene will detect an object that spawns inside it. You don't need to manually interact with it, but adding a second AC_Trigger component to the same Trigger will allow you to have an Enter/Exit pairing that both use the same Collider. Add a Variables component to the same object, define a Bool, and you can then set that Bool to True in OnEnter, and False in OnExit.
The other way to approach this - given your NPC moves between scenes - would be to enable Player-switching, and make the NPC an inactive Player. Inactive Players can be moved between scenes using the Player: Teleport inactive Action, and AC will handle their spawning automatically. Checking if they're in the current scene is then just a case of using the Scene: Check Action which - if player-switching is enabled - can be used to check if an inactive Player is in a given scene.
Ok, I've been doing several tests and I can make it work with OnEnter, but OnExit doesn't work. I switched to detect my player just in case there was some issue with the NPC, but I get the same result. The trigger detects when the Player enters it, but not when they exit.
The interesting part is that both work if I walk outside the trigger. But when I teleport the player, only OnEnter is triggered.
EDIT: Found the solution. I switched the detection mode to Transform Position instead of RigidBody Collision. The only small issue is that it seems I cannot inject the object to detect through a parameter, right?
You can't set what objects the Trigger can detect through parameters, but you can assign the detected object to a GameObject parameter, and then use the ActionList: Check parameter Action to compare its value with another one.
Got it. Thanks