How do I go about making enemies that hear the player loud noises?

Audiobellum

Some I'm making a first person shooter but, I also want their to be simple optional stealth elements in the game. I've found a simple way to make enemies patrol and, even though I haven't tried it yet, I think the player can sneak up on them. However, the enemies can't hear anything. I want to create a system where my enemy AI would be able to hear when the player fires shots and then react to it but, I don't even know where to start. How do I go about making enemies that hear the player loud noises? I just want the enemy to be able to hear when the player fires a weapon alone. Is there a simple way to do this?

Audiobellum

So I've came up with an idea of my own but, I haven't explored it yet. So what I'll express it here before I implement it and then I'll come back if to tell if it's a success. So whenever a shot is fired in the game I'm working on, a bullet hole decal is left on the wall and then it deletes it self after a few seconds. Perhaps I could manipulate the decal to simulate sound to enemies nearby.

Edit: Okay, I've tired it and it works for where the bullet hits. However, I still haven't found a simple solution for the player yet.

Edit again: Okay, so I finally found a solution on my own that was beginner friendly. To simulate the sound of the bullet hitting an object, I made the bullet decals behave similar to that of a raycast grenade. However, instead of damaging enemies nearby, all it does is alter them to the player. In order to simulate the sound of the gun itself, I made sure that the enemy is constantly measuring the distance better them and the player. If the player is close enough, the enemies would shot a "direct_space_state "raycast at the player's direction every time the player's fire's a gun. If the direct_space_state raycast hits the player, the enemy would be aware of the player. I thought that this problem was more complicated than it was, because I heard that simulating hearing in 3d action games involved using navigation meshes.

Loxyrak

A more simple solution would be to add an Area to your Player and everytime you fire, you check if an ennemy is in that area, if yes, set the state of your ennemy to Alerted.
You can have multiples Area for every gun for example representing different levels of sounds. (A small one for your footsteps, etc.)

Audiobellum

@Loxyrak

I'm not too sure to what extend adding more collision shapes/area nodes to the game will affect performance but, I try my best to minimize how many nodes I'm using as much as possible. The goal of my system is to also separate the sound of the gun firing from the sound of the bullet hitting something as well. It makes sense that an enemy from a far won't hear a gun shot from the player but, it would be strange if the bullet where to hit something next to them and they didn't hear it.

newmodels

You could add an area to the loction of the bullet hit, and this would be your heard area.

Another way is to do a simple distance check from the sound of the gun. And also a distance check on the bullet strike. This would mean cycle through all enemies. It could be faster than collision detection, but that depends on the number of enemies you pass through the distance check.

DaveTheCoder

the enemies can't hear anything

What does that mean?

Audiobellum

@DaveTheCoder said:

the enemies can't hear anything

What does that mean?

It means that enemies behave as if they don't hear anything. It's less about them actually hearing sounds and more about them behaving as if they hear sounds; I haven't add actual sounds to the game yet. That said, I know that Godot has an AudioStreamPlayer3D that can be used to simulate 3d sounds for the player. However, I'm not sure if the same can be done for the enemy ai. Is it possible? Is there a way to make enemies/objects in the game "hear" specific actual sounds in 3d using the AudioStreamPlayer3d?

DaveTheCoder

I don't know if it's possible to have objects "hear" sounds. I suspect it would be difficult.

Using the distance from the source of the sound, and possibly taking into account obstacles that might block sound, is probably much easier.

Nerdzmasterz

I will try to put this in Godot terms.

One game set the sound Fx From the source-which was the player- as an animated sprite with a collisionshape. When the Sound signal is emitted, it showed the animation. If an enemy was in range of the animated sprite, the enemy would chase the player.