First of all, kudos and praise to Aaron and Dan for their fantastic work on the new audio engine
I am currently trying to get my head around the new granular synth component, as it might be a great tool for procecdural sound design.
One way to use the granular synth could be for scrubbing through sound files to change for instance the nature of a looped sound - I think there even was a short example of a water stream that was using the granular synth to scrub through a ramping up water sound depending on the strength of the stream in the GDC presentation.
So I am trying to build a system that uses the sample of a pass by of an engine which then can be scrubbed through forward and backward at various speeds and even halting the playhead at any position within the audio file resulting in a short looped section at the playhead’s position. This is a common feature in Granular instruments like the Mach5 VST sampler, and I am super excited to probably have a similar feature now within Unreal.
I could not find any documentation yet on the granular synth unfortunately, so I have to figure out the function of the various granular synth nodes simply by their names and their pins and values and by trial and error.
So far I have been able to simply play back a wav file (which is a 10 second recording of an engine pass by) by creating this setup in Blueprints:
Adding these nodes allows me to monitor the position of the playhead while it moves through the wav file during playback:
So far so good, when testing ingame I can see the position of the playhead then counting up and going back to 0 when it reaches the end of the wav and restarts playback.
Now I want to control the position of the playhead. To do this I insert the “Set Scrub Mode” node and tick its checkbox which seems to stop the playhead from moving through the sound, then I add the “Set Playhead Time” node and set the value for its position to 5 seconds, as this would be the middle of the wav file:
I would expect the granular synth now to play back a tiny section of the wav file at the 5 secs mark of the sound. But ingame I hear no sound at all, and the playback position seems to stay at the 0.0 position according to the debug displayed by the print screen setup in the second picture.
I hope this all makes sense
So does anybody have an idea what I am doing wrong here?