Add Sounds to Fire Traps

In this tutorial, you will add a sound effect to the fire traps in the level. You will create a Sound Cue asset to choose which audio file to play, which we have provided with the project files. 

You’ll then create a Sound Attenuation asset to modify how the sound is perceived by the player. This asset contains settings such as attenuation inner radius and falloff distance, and whether the sound is spatialized in 3D space.

Finally, you’ll update the fire effect’s blueprint to add an Audio component, and start or stop the sound effect based on whether the fire is active.

Before You Begin

Make sure you understand these topics covered in the Unreal Engine for New Users documentation:

• Blueprint basics, such as adding and connecting nodes.

You’ll work with the following assets in the Set Up Your Project and Import Content:

• S_Fire sound wave file

• BP_TrapFire blueprint

Create a Sound Cue

To begin, you’ll create a Sound Cue, which is a node-based audio asset.

A Sound Cue is an audio asset that can contain references to one or more audio files, and instructions on how to manipulate audio as it flows through the graph. This is similar to how Blueprints are used to add functionality and logic to gameplay objects. The Sound Cue Editor has a list of Sound Node types that you can use to control your sound effects.

To create a Sound Cue asset, follow these steps:

1. In the Content Browser, go to the Content > AdventureGame > Artist > Audio folder.

2. In the Audio folder, create a new folder named Fire.

3. In the Fire folder, right-click the asset area, go to Audio, and select Sound Cue.

4. Name this asset SC_FireTrap and open it.

   

  The asset opens in the Sound Cue Editor, which might feel similar to the Blueprint Editor.

The Sound Cue Editor comes with many nodes and settings you can use to customize your sound effects. For this tutorial, you’ll add an audio file you’d like to play and make it loop.

To add an audio file to the Sound Cue, follow these steps:

1. Right-click and add a Wave Player node.

   

2. Connect the Wave Player’s Output pin to the Output node. The Output node is always the last node in a Sound Cue.

   

3. Select the Wave Player node. In the panel to the left side of the window, change the Sound Wave to the S_Fire Sound Wave file you imported in Set Up Your Project and Import Content.

   

4. Turn on Looping so the audio can play on repeat.

   

5. Save the Sound Cue.

You have now created a Sound Cue with the audio file that should play for each fire trap. You can close the sound cue editor.

Control the Sound With a Sound Attenuation

Next, you need to create a Sound Attenuation asset that you can use to change audio settings like the falloff distance, the radius of the audio zone, and more.

Your sound attenuation settings should be set up so that: 

• The fire sound is at full volume only within that trap’s bounds.

• The fire sound’s volume decreases (falls off) as the player moves away from the trap.

• The fire sound isn’t audible once the player is a few meters away from the trap.

This ensures the player can’t hear the fire sound until they are in the same room as the traps and they don’t hear audio from all traps at once.

To create a sound attenuation asset, follow these steps:

1. Go to the Content Browser. In the Audio folder, right-click, go to Audio, and select Sound Attenuation.

2. Name this asset SA_FireTrap and open it. The sound attenuation asset is a data asset, which means that you will see a Details panel with several settings.

   

3. Under the Attenuation (Volume) category, change the following settings in the sound attenuation asset:

   1. Inner Radius: 100

   2. Falloff Distance: 600

      

4. Save SA_FireTrap and close the window.

Now, you have the attenuation settings for your sound effect saved as an asset.

Modify the Fire Trap Blueprint

In the BP_TrapFire blueprint, you will bring together the Sound Cue and Sound Attenuation assets and define when the audio should start and stop.

To modify the blueprint, follow these steps:

1. Go to the Content Browser and navigate to the AdventureGame > Designer > Blueprints > Traps folder.

2. Open the BP_TrapFire blueprint.

3. In the Components panel, click Add, and add an Audio component.

   

4. Select the Audio component. In the Details panel, go to the Sound section, and set Sound to the SC_FireTrap asset you created.

   

5. Optionally, you can modify the Volume Multiplier field to change the volume of this sound effect.

6. In the Attenuation section, set Attenuation Settings to the SA_FireTrap.

7. Ensure Allow Spatialization is enabled, which makes the audio play at a higher volume if the player is closer to it.

   

Next, you will change the graph of this blueprint to add the logic for starting and stopping the audio. The fire trap gets activated and deactivated, so since that logic already exists, you’ll extend it by adding the relevant nodes.

To add the functionality to stop the audio when the trap is disabled, follow these steps:

1. In the BP_TrapFire blueprint editor, go to the Event Graph tab.

2. Locate the red Event fnBPISwitchOn node and go to the last node in that sequence. You can use CTRL + F to search for a node.

   

3. Drag the Audio component into the graph after the Set Material node. This creates an Audio node.

   

4. Drag off the Audio node’s pin and add a Stop node (under the Audio category).

5. From the Audio node, drag the exec input pin and connect it to the Set Material node’s exec pin. This will stop playing the sound that the Audio component plays.

   

Under this sequence of nodes, you’ll see another sequence that starts with the Event fnBPIButtonOff node. 

To play the audio when the trap is active, follow these steps:

1. Locate the red Event fnBPISwitchOff node and go to the last node in that sequence.

2. Drag off the Set Material node’s exec pin,  search for play audio in the node actions list, and add a Play (Audio) node. The Audio component is automatically added as the Target.

   

3. Compile and Save the blueprint.

Now, you have modified the fire trap’s blueprint to play the sound effect upon activation. Your final blueprint graph should look like this:

You can now close the BP_TrapFire blueprint editor.

In the level viewport, if you select a fire trap in your level, you’ll see two spherical wireframes around the actor: the inner sphere shows the sound’s Inner Radius, and the outer sphere shows the sound’s Falloff Distance.

You can now play your game and hear the sound effect when the fire traps are active!

Next Up

Next, you’ll continue working with audio and learn to use Unreal Engine’s Metasounds system to procedurally generate background music for your level.

• 

  Create Procedural Music

  Create Procedural Music with MetaSounds.