Show HN: I built a synthesizer based on 3D physics

100 comments

·May 2, 2025

I've been working on the Anukari 3D Physics Synthesizer for a little over two years now. It's one of the earliest virtual instruments to rely on the GPU for audio processing, which has been incredibly challenging and fun. In the end, predictably, the GUI for manipulating the 3D system actually ended up being a lot more work than the physics simulation.

So far I am only selling it direct on my website, which seems to be working well. I hope to turn it into a sustainable business, and ideally I'd have enough revenue to hire folks to help with it. So far it's been 99% a solo project, with (awesome) contractors brought in for some of the stuff that I'm bad at, like the 3D models and making instrument presets/videos.

The official launch announcement video is here: https://www.youtube.com/watch?v=NYX_eeNVIEU

But if you REALLY want to see what it can do, check out what Mick Cormick did with in on the first day: https://x.com/Mick_Gordon/status/1918146487948919222

I've kept a fairly detailed developer log about my progress on the project since October 2023, which might be of interest to the hardcore technical folks here: https://anukari.com/blog/devlog

I also gave a talk at Audio Developer Conference 2023 (ADC23) that goes deep into a couple of the problems I solved for Anukari: https://www.youtube.com/watch?v=lb8b1SYy73Q

Visit

AaronAPU

Glad I’m not the only audio developer around here.

The landing page needs an immediate audio visual demo. Not an embedded YouTube but a videojs or similar. Low friction get the information of what it sounds and feels like immediately.

My 2 cents

kookamamie

Exactly. Had to scroll for ages to find anything to do with demo audio. A good demo song/track should be the first thing on the page, I think.

senbrow

1000% - I had to be able to find something listenable

airstrike

Really cool stuff! I would suggest putting a 60-second video at the very top of the page that stitches together short clips of the many ways it is awesome.

nayuki

This reminds me of the reverse, where music drives 3D animations. I remember Animusic from the early decade of 2000.

https://en.wikipedia.org/wiki/Animusic , https://www.animusic.com/ , https://www.youtube.com/results?search_query=animusic , https://www.youtube.com/@julianlachniet9036/videos

humbledrone

I'm a huge fan of Animusic. I remember seeing it for the first time in some big fancy mall in LA and they had it projected on a wall, and I was blown away. It was absolutely an inspiration! Animusic -type ideas are a big part of why I made the 3D graphics fully user-customizable, for anyone who wants to go deep down that rabbit hole.

mjcohen

I have the first two Animusic reels (vhs and dvd) and thought they were great. Unfortunately, the creator scammed people by taking money for Animusic 3 and then not making anything.

Most of them are on youtube.

ssfrr

I’m very curious about your experience doing audio on the GPU. What kind of worst-case latency are you able to get? Does it tend to be pretty deterministic or do you need to keep a lot of headroom for occasional latency spikes? Is the latency substantially different between integrated vs discrete GPUs?

humbledrone

Short answer: it has been a big pain in the butt. The GPU hardware is mostly really great, but the drivers/APIs were not designed for such a low-latency use case. There's (for audio) a large overhead latency in kernel execution scheduling. I've had to do a lot of fun optimization in terms of just reducing the runtime of the kernel itself, and a lot of less-fun evil dark magic optimization to e.g. trick macOS into raising the GPU clock speed.

Long answer: I've written a fair bit about this on my devlog. You might check out these tags:

https://anukari.com/blog/devlog/tags/gpu https://anukari.com/blog/devlog/tags/optimization

ssfrr

Thanks for the extra info, I read through some of your entries on GPU optimization and it definitely seems like it's been a journey! Thanks for blazing the trail.

tarentel

Not sure I'll ever use this as it seems like a lot of work but wanted to say thank you for allowing me to download a demo without giving an email.

Also, even though I said I wouldn't use it, something that would be nice is a master volume, maybe I missed it. I often use VSTs standalone and being able to change the volume without messing with the preset would make it a bit easier to use.

Definitely the most interesting synth I've ever seen.

humbledrone

Thanks, yeah, it really should have master volume -- you didn't miss it, it's just not there yet!

florilegiumson

Really cool to see GPUs applied to sound synthesis. Didn’t realize that all one needed to do to keep up with the audio thread was to batch computations at the size of the audio thread. I’m fascinated by the idea of doing the same kind of thing for continua in the manner of Stefan Bilbao: https://www.amazon.com/Numerical-Sound-Synthesis-Difference-...

Although I wonder if mathematically it’s the same thing …

sitkack

I would love to watch (and listen) to a discussion between you and Noah from Audiocube, https://news.ycombinator.com/item?id=42877399 https://main.audiocube.app/ a 3d spatial DAW.

humbledrone

I have been peripherally aware of Audiocube for a while, and it seems ridiculous that he and I have not interacted in any way. Maybe I'll bug him sometime. :)

jbverschoor

Man. “Sheet music is not portable”. I immediately thought about the Apple Vision Pro

The battery-less medium is something we do desperately try to mimic

smolder

I have mixed feelings about all of my supposed clever ideas being executed on by other people way ahead of me, but this is cool and you have my respect.

nyanpasu64

The sounds seem to mostly be modulated sines with limited timbral variety? I'm not sure how https://youtu.be/NYX_eeNVIEU?t=179 got harmonic series out of the building blocks.

adzm

Note they are referring to Mick Gordon who is notable for the recent DOOM soundtrack. DOOM Eternal has a truly phenomenal score. Mick Cormick is a mistake I believe.

Congratulations!!

humbledrone

Oh goodness, that's truly embarrassing that I typoed "Mick Cormick" instead of Mick Gordon. O_o I wonder if my brain somehow crossed wires with John Carmack. Thanks for the correction!

tbalsam

McCormick is a popular brand of seasonings hahaha

https://i5.walmartimages.com/seo/McCormick-Pure-Ground-Black...

throwaway7894

Of note is the drama surrounding the Doom Eternal soundtrack: https://medium.com/@mickgordon/my-full-statement-regarding-d...

sunray2

Thank you for this, it looks very cool!

Remind me of Korg's Berlin branch with their Phase8 instrument: https://korg.berlin/ . Life imitates art imitates life :)

I highly support and encourage this. Is there a way I could contribute to Anukari at all (I'm a physicist by day)? These kinds of advancements are the stuff I would live for! However I should stay rooted in what's possible or helpful: I'm not sure if this is open-source for example. As long as I could help, I'm game.

humbledrone

For the foreseeable future I'm just going to be working on stability/performance, but eventually I will get back to adding more cool physics stuff. It's not open-source, but certainly I'd enjoy talking to a real physicist (I'm something a couple notches below armchair-level). Hit me up at evan@anukari.com sometime if you like!

sunray2

Thanks, will hit you up later!

I was using the demo just now: the sounds you get out of this are actually better than I expected! And I see what you meant in the videos about intuitive editing, rather than abstract.

Although, I was often hitting 100% CPU with some presets, with the sound glitching accordingly. So I could experiment only in part. I'm on an M1 Pro; initially I set 128 buffer sample size in Ableton but most presets were glitching, I then set to 2048 just to check for improvement, which it did, nevertheless it does seem a bit high. Maybe my audio settings are incorrect? I can give more info later if it helps you.

humbledrone

Yeah performance at low buffer sizes is a big challenge, generally I recommend 512 or higher, which I know is not great but right now it's the most practical thing. The issue is that the computation is all done on the GPU, and there's a round-trip latency that has to be amortized. One day I'd like to convince Apple to work on the kernel scheduling latency...