Unreal Engine Blueprint – Trigger a sound on and off using a trigger box

This can be used to trigger a sound or music file if your character enters the trigger box.

1. Add an ‘Audio’ component in the components section:
   • When selected (on the right hand-side details panel) there are many details for it.
   • Add the required audio file.
   • Remember to turn off auto-activate in the details panel otherwise it may play on the begin play of the level.
   • You can also add an attenuation file here if you wish.
2. Add a Collision Box:
   • Add a ‘Box Collision’ in the components section.
   • Resize and position to the required size.
3. Static Mesh:
   • If you wish you can add a ‘StaticMesh’ component.
   • And add a mesh such as a radio or record player.

4. Adding Code into Event Graph:

• In the ‘Event Graph’
• Whilst this Collision Box is selected in the components panel.
• In the details panel on the right hand side.
  • Scroll down and select:
    • ‘On Component Begin Overlap.’
    • Select the Collision box again and select:
    • ‘On Component End Overlap.’

• Next, drag off from the ‘On Component Begin Overlap’ node execution pin and search for Play Audio.
  • Drag the audio component, from the components list, on the left into the event graph
  • Drag off from the Audio component variable and plug into ‘Target.’ (If its not already connected).
• Drag off from the ‘On Component End Overlap’ node execution pin and search for Stop audio.
  • Drag off from the Audio component variable and plug into ‘Target.’ (If it’s not already connected as it may get auto added when adding the play or stop audio nodes – if so it can be deleted as two of these nodes is not needed).
  • The blueprint can now be added into the level in the required place.
  • All done!

For further overviews on how to create Blueprints in Unreal Engine please see the tutorials and tips section or see the intro and getting started with Blueprints post.