How much can Unreal Engine and MetaSounds accomplish? Developer/artist Matt Spendlove has built a complete open-source polysynth in it, roughly recreating the AudioKit Synth One using Unreal’s internal tools.
You can grab this creation and run it for free, and Unreal Engine is free for most usage. But this is instantly great, because it shows one thing that’s not so obvious in MetaSounds, which is how to patch polyphony. Watch – complete with nice UI and a pretty oscilloscope powered by the Niagra particle engine:
Before you dive in, your best bet is to look first at Matt’s terrific MetaSounds tutorial on the Epic Learning Portal:
Introduction to MetaSounds [Epic Games community site]
That comprehensive learning guide comes with a companion GitHub repository full of examples:
Project files for official Epic Developer Community course
It doesn’t cover all the latest features, but it’s up to date for all the basics and the best available learning guide.
From there, though, it’s worth peeking inside MetaSynthOne – hat tip to the AudioKit team. (To be clear, AudioKit doesn’t run inside Unreal Engine – this was just an example inspired by their free example.)
There’s a lot here – this not only solves the question of polyphony but also how to create custom source engines and how to interact with UI (and visualization). As Matt writes:
As at August 2024, MetaSounds don’t support polyphony out of the box so you need to roll your own solution. Whilst MetaSounds support some native interaction with the wider engine, first class support for other core UE5 features (e.g. Sequencer and Blueprint Scripting) requires the MS to be wrapped in a Blueprint. The MetaSynthOne reference implementation here wraps up that plumbing and allows easy intergration with Unreal Motion Graphics (UMG) for creating User Interface widgets to control the synth engine at runtime.
In short, I now have an extensible way to design custom MetaSound Source sound engines, hook them up to gameplay interactions and publish custom UI widgets to allow me to tweak the sound in realtime. I can also do “offline” sound design to create standalone presets for recall later.
As I write this, it isn’t quite ready for you to incorporate into your own projects or to modify on your own. As Matt suggests, it’s better just to look around and use it as a reference for your own creations. But it is ready to play with. Just be sure to resist the temptation to try to use the download button and go ahead and actually work from the Git interface (desktop or CLI). (In fact, with developer projects, you should get in that habit generally – a lot of stuff breaks when using download because of submodules and whatnot.)
Oh, and compellingly, Matt is promising more to come, with this repository being a home to future, as-yet-unannounced examples. Hell, yeah!
MetaSounds Synth Repo [GitHub]
Previously: