project name: euclidigons
project url:
authors: synthetivv setfield
description: geometric rhythm generator
discussion url:
tags: sequencer synth


Sequencer for monome norns, imagined by and realized in collaboration with @setfield




At startup, there will be two shapes visible on the screen. Think of the polygons’ sides as strings: when a side is crossed by one of the other shapes’ vertices, the string is plucked or struck.* The faster the side-string and vertex-plectrum are traveling relative to one another, the louder and brighter the note will be; and different harmonics will be emphasized depending on where along its length the string is struck.

E1 chooses a shape to edit.
E2 moves it along the X axis.
E3 changes its size.
K1+E2 sets the note to which its sides are tuned.
K1+E3 transposes the note in octaves.
K2+E2 sets rotation rate.
K2+E3 sets the number of sides (1-9).
K3 mutes or unmutes the selected shape.†
K1+K2 deletes the selected shape.
K1+K3 inserts a new shape.

Arc encoders are also supported and edit the currently active shape:

ARC 1 sets the note.
ARC 2 transposes the note in octaves.
ARC 3 sets the rotation rate.
ARC 4 sets the number of sides (1-9).

* by default, notes are only sounded when one shape’s vertex crosses into another shape, but this can be changed using the ‘trigger style’ param.
† set the ‘mute style’ param to ‘own note only’ to allow a muted shape’s vertices to pluck the strings of another shape.

about the engine

PrimitiveString “models” a plucked string in the style of Kazimir Malevich. A blend of two basic tone generators – a “nulse” pulse wave with added AM’d white noise, and a “caw” comb-filtered sawtooth wave – is fed through a low pass filter and multiplier. Overall amplitude, LPF cutoff, noise amount, and comb filter feedback are all controlled by a single attack-release envelope.

Settings exposed in Norns params:

amp: this one is simple: volume
waveform (pulse/saw): blend between the two waveforms/generators described above; 0.0 = pure pulse, 1.0 = pure saw
pulse noise: the amount of noise present in the pulse waveform
saw comb: the decay (in seconds) of the comb filter fed by the saw waveform
brightness: sets maximum filter cutoff
attack: AR envelope attack time in seconds
release: AR envelope release time in seconds