Get / Set Low Pass Filter does not appear to function at runtime

Summary
Get / Set Low Pass Filter does not appear to function at runtime

Description
An Audio Component contains a ‘Filter’ section in its Details, which includes a tick box to ‘Enable Low Pass Filter’ and place to set the ‘Low Pass Filter Frequency’. Ticking the box and setting a value can be observed to apply a low pass filter when playing the game.

134592-details.jpg

There are also nodes available in Blueprints which appear to allow the user to get and set these options. For example, ‘Set Low Pass Filter Frequency’ and ‘Get Enable Low Pass Filter’.

134593-blueprint1.jpg

It currently appears that if these are used within blueprints, they have no effect on an Audio Component at runtime.

Steps to reproduce

  1. Launch Unreal Editor 4.14.3.
  2. Create an instance of an Audio Component in any level.
  3. Access the Details pane for the Audio Component, and tick ‘Enable Low Pass Filter’.
  4. Edit the level Blueprint and configure a ‘Set Low Pass Filter Frequency’ node to adjust the frequency of the filter in the Audio Component.
  5. Play the game and cause the ‘Set Low Pass Filter Frequency’ node to trigger.

Expected Results
When in gameplay, triggering the ‘Set Low Pass Filter Frequency’ node should cause the frequency of the Low Pass Filter on the Audio Component to change.

Actual Results
The ‘Set Low Pass Filter Frequency’ node appears to have no effect on the frequency of the Low Pass Filter on the Audio Component when in gameplay.

134595-blueprint2.jpg

Hey mate,

Pretty sure this wont work in the current version of the engine, although audio enhancements are coming in 4.16 and will continue in future iterations of the engine.

You could try using a even tick tick to drive the filter change into a “lerp to” node and set the float variable that way. You could use some flow control nodes, perhaps a do once, if you still want to use your key input. You could also use a timeline to do modulate the float.

But unfortunately, like I said, pretty sure this functionality isn’t supported… yet!

Thanks for that. Some things to try there. :slight_smile:

I have been watching the recent audio announcement vids from @minuskelvin (who is rewriting the entire audio engine!) so I am hopeful such things will be addressed and improved.

Glad to hear that. :slight_smile: If you have any luck do chime in here with any further ideas, I will do the same. :slight_smile:

This post couldn’t have been better timed for me. Thanks for the suggestions!