New Free Open Source Synth, Terrain, By Aaron Anderson

[aaron_anderson]

@Aaron - I know Andreya has been in touch and would be great to see you in the surge tuning channel, but also the way I often share the simplest MTS onboarding is to share the single diff I did to take monique from 440 * 2^((key-69)/12) to that or MTS-ESP client.

https://github.com/surge-synthesizer/mo ... 52cb9e30ff

It's three years old but is basically the same today. I introduced a tuning handler with that in case I wanted to do direct SCL/KBM but never got around to it in monique. Hope that helps!

Peking at your code, you probably want to just replace

```
setFrequency (static_cast<float> (juce::MidiMessage::getMidiNoteInHertz (midiNoteNumber)));
```

with an if-client-bound-client-frequency-else-that.

Thank you for this! I should be getting around to it pretty soon now.

[Lind0n]

Can I add one more voice for MIDI learn - and suggest you might want to consider pushing this up the priority list, it will make sounds repeatable and still retain the motion you have....

[aaron_anderson]

OK - I found something. If you save a Reaper preset with settings that you like, then play around - if you then load the Reaper preset, then none of the controls work anymore. In other words, Terrain is frozen at the settings of th eReaper preset (and works fine) but you can't change anything.

This is now fixed in version 1.0.3! Thank you for finding this bug. Link to installers has been migrated to github/releases: https://github.com/aaronaanderson/Terrain/releases

[aaron_anderson]

Hi all!

Version 1.0.3 is complete. Installers: https://github.com/aaronaanderson/Terrain/releases
-Adds Pitch Bend
-Sustain control now in Decibels
-Fixes Zero-Sustain bug
-Fixes Preset Saving bug in Reaper
-Stability Improvements

Best,

Aaron

[aaron_anderson]

Can I add one more voice for MIDI learn - and suggest you might want to consider pushing this up the priority list, it will make sounds repeatable and still retain the motion you have....

When generating the roadmap I balance the number of requests from the community with how much work a feature will take. MIDI Learn will be a time consuming feature to implement - but your voice is heard. I moved it up on the roadmap: https://github.com/aaronaanderson/Terra ... RoadMap.md

[El°HYM]

You're very welcome! Fortunately 16x is pretty overkill. I tried the worst-case scenario (the butterfly trajectory on a fully saturated terrain, with the highest note on the keyboard) and 8x oversampling was enough to remove any audible aliasing. For nearly all use cases I would recommend 2x.

Thank you for testing!

88 or 61 Keys, because a lot of digital ones start get really ugly above C5.

I just tested again and you're right; it is easy to get aliasing with the sinusoidal terrain with maximum harmonics, the scale of the trajectory large, and the butterfly trajectory even at 16x oversampling.

Btw.

What is your take on ADAA?

https://ccrma.stanford.edu/~jatin/Notebooks/adaa.html

https://www.researchgate.net/publicatio ... onvolution

[aaron_anderson]

I actually hadn't heard of ADAA. This is really interesting, thank you for bringing it to my attention. It would seem that a 'trivial' implementation would be possible in Terrain; take the first or second order antiderivative of both the trajectory and terrain function independently. Each successive antiderivative order seems to increase the computational cost; likely not near as much as the oversampling however. It would be a nice feature to provide both orders of antiderivatives as options in addition to oversampling. I would really have to brush up on my calculus to pull that off though.

[muki]

working fine in logic under mojave
uhm...:
in re pitchbend, it would imho be fine to be able to set the semitone value
12 semis (1 full octave) as it is now is imho to much (as a default)...

[aaron_anderson]

working fine in logic under mojave
uhm...:
in re pitchbend, it would imho be fine to be able to set the semitone value
12 semis (1 full octave) as it is now is imho to much (as a default)...

I plan to add a setting for this to be changed by a user in the future. I'll make the default a whole step.

[El°HYM]

I actually hadn't heard of ADAA. This is really interesting, thank you for bringing it to my attention. It would seem that a 'trivial' implementation would be possible in Terrain; take the first or second order antiderivative of both the trajectory and terrain function independently. Each successive antiderivative order seems to increase the computational cost; likely not near as much as the oversampling however. It would be a nice feature to provide both orders of antiderivatives as options in addition to oversampling. I would really have to brush up on my calculus to pull that off though.

First Time I have heard of it was via TBT. So thats pretty much what I have for now. Some of the more interesting stuff on this topic so far, imho.

https://www.threebodytech.com/en/produc ... compressor

Anti-derivative anti-aliasing is a method to reduce aliasing artifacts in nonlinear audio processing without the use of oversampling. It transfers discrete sampling points into continuous signals, which provides the system an unlimited sample rate that remarkably reduces aliasing. The technique was initially invented by Native Instruments,[1] and was then gradually utilized in a number of waveshapers in the following years.

[Borbolactic]

I've updated the links in my posts to also reflect installers' location.

TY for Version 1.0.3, Aaron, and to others' input and support!

" 'You can be creative in any right place on Earth, and not only in the wealthiest cities. Bring the world feelings from everywhere, and not only feelings of capitalistic or jail environment.' ― Aleksey Vaneev"

~ El°HYM (signature quote)

Agreed.

"You often need money to change things. But most ways of acquiring it require you to compromise on your ideals. We can do better than that." ~ Peter Sunde

[Weasel-Boy]

Interesting unit. Using the VST3 version on an M1 Macbook, I found that turning on the filter introduced a fair amount of distortion, regardless of settings.

[baconpaul]

I actually hadn't heard of ADAA. This is really interesting, thank you for bringing it to my attention. It would seem that a 'trivial' implementation would be possible in Terrain; take the first or second order antiderivative of both the trajectory and terrain function independently. Each successive antiderivative order seems to increase the computational cost; likely not near as much as the oversampling however. It would be a nice feature to provide both orders of antiderivatives as options in addition to oversampling. I would really have to brush up on my calculus to pull that off though.

We use it quite a lot in surge. Both in vcos and waveshaoers. Feel free to fire me questions on discord or in pm if you want examples but it works really well.

Key insight is that the numerical derivative of the analytic integral is equivalent form to alias supressing filters but happy to share papers code blogs etc

From playing with terrain i would think a blit approach may also work (I haven’t read the code but I assume you are just putting position on surface into output and there may be better techniques to reconstruct)

Anyway as well as the tuning channel we have a dsp channel and always happy to shoot the you know what with friendly oss devs

[muki]

I plan to add a setting for this to be changed by a user in the future. I'll make the default a whole step.

[veloheinz]

Thanks Aron for Terrain,
what is the difference to sonic-lab.com/oceanic ?