Key Concepts

Understanding Arkestra’s hierarchy makes everything else click.

The hierarchy

Project
└── Track  (many)
    └── Chain  (many, one active at a time)
        └── Device  (many, in order)
            └── Parameter  (many)

Every piece of visual output flows down this tree, frame by frame.

Project

A Project is the top-level document. It holds all tracks, scenes, snapshots, and global settings. Projects are saved as .vfx files.

The project also owns a Master Track — a special chain applied to the final blended output before it goes to the canvas, recorder, and Syphon/NDI outputs.

Track

A Track is a mixer lane. Think of it like a channel strip in a DAW. Each track:

Has one or more Chains (its effect rack presets)
Blends its output into the master mix via opacity and blend mode
Has a TrackType that determines what kind of content it produces

See Track Types →

Chain

A Chain is an ordered list of Devices. Only one chain is active per track at a time, and you can swap between them instantly during a performance (like scene switching within a track).

Each chain also has:

A pre-feedback section (effects before the feedback loop tap)
A post-feedback section (effects applied after)
Up to 5 Chain Macros — user-defined knobs that can drive multiple parameters at once

Device

A Device is a single node inside a chain. It can be a Generator (produces pixels — an ISF layer shader, video file, camera feed, 3D scene, Syphon input) or an Effect (transforms the previous output — an ISF effect shader, GPU effect, feedback modifier).

Every device has:

Parameters — the controls exposed by the shader or renderer
Dry/Wet — blend the output with the input
Bypass — pass the input through unchanged
ISFMixer — the blend mode used when compositing this device’s output

Parameter

A Parameter is one user-controllable input on a device. Parameters are typed:

Type	Example
`float`	Speed, Scale, Brightness
`bool`	Enable, Mirror
`color`	Tint, Background color
`select`	Blend mode, Wave shape
`point2d`	Center, Offset
`texture`	Input image/video

Any float or bool parameter can be modulated — driven by an LFO, audio signal, MIDI, OSC, sequencer, or another parameter source.

Modulation sources

A ParameterSource can be any of:

Fader — direct manual control
LFO — oscillator (sine, square, triangle, ramp, and more)
Sequencer — step sequencer (up to 16 steps)
Audio — kick, snare, and hi-hat detector ranges
MIDI — CC value from any connected device
OSC — incoming OSC message value
Global LFO / Global Sequencer — project-wide shared modulators
Vision — face, hand, and body tracking
Timeline — automation lane