> ## Documentation Index
> Fetch the complete documentation index at: https://docs.baryon.live/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Parameter Automation

> Control Baryon Desktop from OSC software, OSCQuery-aware tools, and MIDI control-change hardware.

Baryon Desktop can accept parameter automation from OSC software and MIDI
control-change hardware. Open Performer Mode, open **Control I/O**, turn on the
top **Enable** switch, and enable the transports you want.

<Note>
  This page is for inbound control: external tool -> Baryon. To send Baryon's
  modal structure out to TouchDesigner or another receiver, use
  [OSC Structure Export](/public/desktop/osc-structure-export).
</Note>

OSC listens on `127.0.0.1:9001` by default. Send messages to
`/baryon/control/<key>`, where `<key>` is one of the automatable control keys
below. MIDI v1 maps one selected MIDI input at a time; use learn mode to bind a
knob or fader CC message to the same key list.

When OSC is enabled, Baryon also serves an OSCQuery discovery endpoint on the
next local port: `http://127.0.0.1:9002` by default. If you change the OSC port,
the OSCQuery port follows as `OSC port + 1`. Use **Copy Ref** in the control
I/O panel to copy the current OSC/OSCQuery reference.

OSCQuery is discovery only. It tells external tools what Baryon can control,
what OSC host and port to use, and how each value should be shaped. Control
values are still sent over OSC UDP.

## MIDI Setup

Baryon's MIDI input is for MIDI control-change messages. A MIDI keyboard can
work if its knobs, faders, or pads send CC messages; piano notes, pitch bend,
and aftertouch do not control Baryon in this first automation surface.

Use a physical MIDI controller like this:

1. Connect the MIDI controller to the computer running Baryon.
2. In Baryon Desktop, open **Control I/O**, turn on **Enable**, and enable
   **MIDI**.
3. If the app asks for MIDI access, allow it.
4. Choose the controller under **Input**.
5. Choose the Baryon parameter under **Target**.
6. Press **Learn**, then move one knob, fader, or CC-capable pad on the
   controller.
7. Move that same control again. Baryon should update the mapped parameter and
   the `ok` counter should increase.

Use virtual MIDI on macOS like this:

1. Open **Audio MIDI Setup**.
2. Choose **Window > Show MIDI Studio**.
3. Open **IAC Driver**, enable **Device is online**, and add or select a bus.
4. In Baryon, open **Control I/O**, turn on **Enable**, enable **MIDI**, then
   select the IAC bus under **Input**.
5. In a DAW, TouchDesigner, Max, or another MIDI source, send MIDI CC messages
   to that same IAC bus.
6. In Baryon, choose a **Target**, press **Learn**, and move or send the CC
   control once to bind it.

### Learn and Remove Mappings

The **Learn** button binds one physical MIDI control to the selected Baryon
target:

1. Choose a Baryon parameter in **Target**.
2. Press **Learn**. The button changes to **Learning**.
3. Move one knob, fader, or CC-capable pad on the selected MIDI input.
4. Baryon records that input, MIDI channel, CC controller number, and target.
5. Move the same physical control again to drive the mapped Baryon parameter.

Learning the same physical CC again moves that CC to the newly selected target;
other mapped CCs remain until you remove them.

The **X** button next to the shown mapping removes that mapping. Use it when you
want the selected target to stop responding to the current MIDI control, or
before teaching that target a different physical control.

The **Control changes** menu controls whether incoming OSC/MIDI value changes
are saved as visual settings. **Session only** applies external control without
saving the changed Baryon values. **Remember** saves the changed values after
Baryon's normal debounce. Learned MIDI mappings are saved with the control-input
configuration either way.

## TouchDesigner Control Surface

Download the smart TouchDesigner component:
[baryon\_osc.tox](https://downloads.baryon.live/touchdesigner/baryon_osc.tox)

Use it like this:

1. In Baryon Desktop, open **Control I/O**, turn on **Enable**, and enable
   **OSC**.
2. For local TouchDesigner on the same machine, leave OSC at
   `127.0.0.1:9001`. OSCQuery will be available at `127.0.0.1:9002`.
3. Drag `baryon_osc.tox` into a TouchDesigner network.
4. Select the parent `baryon_osc` component and pulse **Refresh Query**.
5. Select `baryon_osc/controls` and tune the generated custom parameters.
6. Use **Send All** on the parent component to push the current TouchDesigner
   values to Baryon.

The parent `baryon_osc` component owns OSC host/port, OSCQuery host/port,
Bonjour discovery, refresh, active state, and Send All. The child
`baryon_osc/controls` component is the control surface. It is regenerated from
Baryon's OSCQuery metadata, so pages such as Shape, Motion, Bloom, Color,
Output, Performance, and Logo track the Baryon build you are running.

Before OSCQuery is reachable, the component starts with a small Shape, Motion,
and Bloom fallback surface. After **Refresh Query** succeeds, the fallback is
replaced by the discovered Baryon controls.

For a second computer on the same network, turn on **LAN** in Baryon. LAN mode
binds OSC/OSCQuery to the local network and advertises OSCQuery over Bonjour as
`_oscjson._tcp` / `Baryon Parameter Automation`. In TouchDesigner, pulse
**Discover** if Bonjour is available, or enter the Baryon machine's LAN address
as **OSCQuery Host** and then pulse **Refresh Query**.

## Manual OSC

Query `/?HOST_INFO` for the OSC receiver details, `/baryon/control` for the
writable control tree, or a specific address such as
`/baryon/control/zeroPointPrecision` for type, range, description, tags, label,
and default metadata.

Example OSC messages:

```text theme={null}
/baryon/control/zeroPointPrecision 0.12
/baryon/control/bloomEnabled 1
/baryon/control/colorMode spectral
/baryon/control/volumeColor 0.36 0.89 0.96
```

OSC scalar controls take one numeric argument. Boolean controls take one integer
argument, where `0` is off and any non-zero value is on. Enum controls take one
string argument matching the control value. Color controls take three numeric RGB
arguments from `0` to `1`. MIDI mappings scale CC values (`0..127`) into the
target control range.

| Area        | Automatable keys                                                                                                                 |
| ----------- | -------------------------------------------------------------------------------------------------------------------------------- |
| Performance | `renderQualityPreset`, `customTargetFps`, `performanceHudEnabled`                                                                |
| Output      | `outputMode`, `outputBackgroundColor`                                                                                            |
| Shape       | `boundaryMode`, `zeroPointPrecision`, `densityGain`, `absorption`, `opacityGain`, `raymarchSteps`                                |
| Color       | `colorMode`, `volumeColor`, `surfaceColor`, `spectralMix`, `holographicIntensity`, `holographicShift`, `holographicFresnelPower` |
| Motion      | `rotationMode`, `rotationSpeed`, `motionAmount`, `reactivity`                                                                    |
| Bloom       | `bloomEnabled`, `bloomStrength`, `bloomRadius`, `bloomThreshold`, `bloomResponseBias`, `rimBloomBias`, `rimCompression`          |
| Logo        | `idleLogoIntensity`, `idleLogoSize`                                                                                              |

Notes, pitch bend, aftertouch, feedback LEDs, multi-device profiles, and remote
hardware profiles are outside the first automation surface.