Audio Reactivity and RealSense Integration

Hey there,

Can you please tell me where I can download your Audio Reactivity example project, please?

Thank you.

Kind regards,



This sample project is not available anymore unfortunately. We will include it in the future again, for sure (thank’s for reminding us), but what is it that you are trying to do exactly?

Maybe I can help you here.


Hey Mitja,

That’s a shame, please can you let me know as to when it becomes available again?

I would play the harmonica in to the mic and provide some form of visualisation, via single and multiple notes.

Following which, I’d like to relay this data into UE4 to apply further effects.

Could you assist, please?

Thank you.

Hey Mitja,

Could I have some feedback please, thank you.

Kind regards,


Hey Smudgy,

Sorry for not replying sooner.

I am about to create a few audio sample projects on both Lightact and UE side. I’ll post an update when it’s ready.

In general, the layout you’ll be creating will be similar to this:

  1. You should create an Audio input node in the Devices window
  2. in the Audio Input Reader (in your Layer) you should select this node as the parent device
  3. create the layout as shown above and either use the float value in Lightact or pass it on to UE for further visualisation.

Audio FFT node splits the incoming spectrum to either 4, 8, 16, 32… bins where the lower indexes represents the lower tones and the higher the higher tones.

Let me know how it goes,

Thank you Mitja, I will try this out and reprt back the result.

Could you describe how to negate (not) a boolean variable, please?

All the best.

Hey Smudgy,

Awesome! Hopefully, I’ll be able to upload some sample projects and audio sample projects tomorrow.

As for the negate a bool, you can use a Bool Invert node.


Thank you Mitya, that boolean operator is perfect.
Looking forward to playing with the examples.
Sweet =].

Hey M,

Thank you that, it helps tremendously.

Looking forward to seeing how the sample projects work =].

I have another question, if you can answer it, please…

In relation to devices (F7), is there anyway through layer code where you can enable/disable the corresponding streams?

All the best,



No, it’s not, unfortunately, but can you explain why would you want to do that? Maybe there is another way of doing the same thing…


Hey M,

In relation to my devices:

And the code setup on the Audio layer:

I wanted to only provide mic input to the audio output when I toggled the ‘m key’ on/off
However, when I hit play and then ‘m key’, the input to output works ok; although when I hit the ‘m key’ again, I expect the input to output to switch off. It just stays on.

Is there anyway in providing this control method, please? Thank you.

Kind regards,



That is indeed a bug. I’ve inserted it into our database and will let you know when it is fixed (it should be in a day or two). Sorry.


Thank you Mitja for the speedy reply.

I’ll put the project on pause then. Please can you tell me when it has been fixed and what I’ll have to do to incorporate the fix into my current 3.1.2 software version.

Also, when do you intend to upload the Audio Revisualiser project(s), please?

Thank you for your help, really appreciated =].

Also in ‘a day or two’ :smiley:

Sweet M, thank you Dude =]

Hey M,

I hope you’re well?!

Thank you for uploading the example project.

I have opened it and set up the audio input to audio output.

So I can hear the mic imput coming out of the chosen speaker setup.

Again on project stop, the sounds come through, is this part of the bug you stated?

Anyway, device setup:

And modification to program:

Please could you tell me what to do with the FFT output to achieve the changing the 3D effect? Although it appears to have a float output, the symbol has 3 circles, and the output wire cannot be attached to the float reader?!

Is there something else I’m missing?

All the best,


Hello Smudgy,

Tomorrow we are releasing Lightact version v3.1.3, which is going to have all the fixes for the issues you encountered. Sorry to keep you waiting - we wanted to release it today, but there were some last minute things we had to fix :slight_smile:

The ‘3 circles’ connection pins signify an ‘array’. And in order to get a single value from the array, you can use a Get float array item node.

Alternatively, in v3.1.3 you’ll be able to connect the Float array connection directly to Shared memory sender node and send all the data to Unreal in order to achieve something like this:

Again, if you can, please wait until we release v3.1.3. I’ll post an update here once we do that.


That’s fantastic news Mitja =].

Ah, I see, that makes sense, thank you for the helpful information, really appreciated.

Thank you to all the team for the upcoming 3.1.3!


Lightact v3.1.3 has now been published and is available online. You can have a look at the Changelog here.

You might want to download the LightactAndUnreal sample UE project again, as it includes 2 new levels - one of which is the abovementioned audio visualisation. It should work straight-out-of-the-box with the new Audio Visualisation with UE4 sample project that’s available in the Unreal Engine category in the Welcome screen.

Please download the latest Lightact UE4 plugin as well, as we’ve added some additional utility nodes.

If you have any questions, problems or comments, don’t hesitate to ask.


That’s great, thank you Mitja =]