Owner

JerkyTreats

Tags

🎶

This is part of a ongoing series called Building A Music Engine

It documents the process of me smashing my head against the keyboard to build a game called LETSGO

It’s gotten long enough to break into several sections:

‣

Building A Music Engine entries

TLDR: Summer 2024 was crazy busy, and I don’t want to go back and write a huge devlog on something I did weeks ago. But here’s the progress I’ve made:

I’m revisiting this after about 3 weeks, questioning why I’m forcing myself to write these in-depth devlogs.

I bring this up because I don’t remember exactly what I did. Thankfully though, I had a PR:

Refactor InstrumentSchedule to include Notes

Merged

#9 ⋅ JerkyTreats ⋅ a year ago

Unfortunately that PR does not encapsulate the entirety of the work, as evidenced by the commit-to-main shenanigans of:

Start implementing multi-note Instruments

JerkyTreats

Here’s the thing, I don’t want to go back and construct the narrative of what I did. It was basically just updating the data structures to represent something like:

[1, C1], [2, C1], [3, C1], [4, G1]

Where 1 is the beat (quarter note), and C1 is the C note on the first octave (as represented on a MIDI keyboard).

How did I do it? The commits speak for themselves:

Start building some jank ass system to map synth sound to notes

JerkyTreats

Refactor InstrumentSchedule to include Notes

JerkyTreats

Then I did the PR to get the above working.

And it does work. Which is neat.

I lost the thread of this though because then I went 2 solid weeks of trying to debug a bug when collapsing the 48 unique Metasounds into one. It was highly entertaining in that I was idiot the entire time:

AudioComponent SetWaveParameter with PlayQuantized

I have an actor that plays AudioComponent->PlayQuantized() Previously the actor would be initialized with a unique Metasound. On PlayQuantized() it would work as expected. This approach required me to instrument many Metasounds, and instead I’d like to use a single MetasoundSource* that has parameterized inputs. However, now when I run AudioComponent->SetWaveParameter I get unexpected behavior: Audio is being played as if not in the quantization audio thread- sounds are clipped, barely audibl...

forums.unrealengine.com

Once I got it working though, things started moving relatively quickly. I added a Phase to Set the Third - allowing the player to choose a Major/Minor key.

With that though, we can move right along to the thing I actually want to write about:

Generative Music Without LLMs