NIME - Musical Instrument at the Time of the Beta Performance

Nov 7, 2018 18:03 · 723 words · 4 minutes read

This post will go through the state of my musical instrument and the prossess of getting there at the time of the beta performance.

Description

The Liquisynth is a modular synthesis system controlled by the performer and randomness in fluids as observed by cameras.

The whole system together. I hooked up a Novation Launchcontrol XL to adjust the sound levels of each track in Ableton

The instrument now consists of:

An interface built in TouchDesigner. Multiple jars of liquid can be viewed at from a camera. Views of these liquids are cropped from the camera feed, with sliders allowing for specifications of the crops.
The shape of these liquids is used to modulate sounds by turning knobs in the Softube modular synthesizer system with the Buchla 259e twisted waveform generator used as an oscillator to produce unique, rich analog sounds.
This modular system is accessed as a VST Plugin in Ableton, with the knobs linked to TouchDesigner using TDAbleton, “a tool for linking TouchDesigner tightly with Ableton Live. It offers full access to most everything going on in an Ableton set, both for viewing and setting.”

TODO: gif

Each of these views can be recorded independently and played back in the place of a live feed. This allows me to practice different scenarios and tune the instrument without needing to mix liquids live and make a mess.

changing a pre-recorded video for a view

Each view can be switched easily between a live feed or one of these pre-recorded videos.

TODO: gif

For each view, the red, blue and green levels, their amount of fragmentation and horizontal distribution can all be calculated independently.

The controls for filtering red colors, linked to an RGBKey top which extracts an alpha max based on these red, green, and blue ranges.

The values that are extracted based on the filtered color include level, left/right distribution (pan), verticalChangeRate, and fragmentation

Each of these values can be linked to knobs in the Buchla259e Complex Waveform Generator, using Ableton and tdAbleton to have these values linked directly to those knobs.

For each of these extracted values, the scale, min, and max can be set by adjusting knobs:

In particular, the abletonMapper component is used and mapped directly to Softube values:

Any of the above extracted values can be mapped directly to the panning of an ableton track, via the abletonTrack component.

Any view can be solod, making the Ableton track solod and the view shown to the audience only show that component.

Here is one of the views in action:

Fabrication

Now to step back a bit, I will go through the fabrication process.

I met with Eric Rosenthal to figure out how to properly light these liquids to pick up the colors in the best way. He recommended getting full spectrum LEDs. I called LEDSupply and right away someone answered, telling me exactly which ones to get, the 4000k Neutral White Nichia LEDs, as they are powered direclty by 12v, and do not need an LED driver. This would allow me to also control them via PWM from an arduino, letting me programmatically turn them on and off.

4000k and 3500k neutral white leds from LEDSupply.com to illuminate the liquids from behind a translucent acrylic sheet. I also got a few different attachments for diffusing/focusing the lights to try out.

The white LEDs were 12v. A circuit controlling the brightness of leds using PWM and a TIP120 transistor, with the lights connected directly to a 12v power supply.

Placing the LED on an elevated platform to test out the clarity in the camera.

Testing the visibility of the colors with the new form of illumination. This worked well.

I quickly designed and laser cut some black acrylic to act as a mount for the lights, with a larger size hole for the wires.

The light holders assembled. I made two of them to try out different heights of the lights.

I made two sets of stands and light holders, to allow for two liquid containers to be performed with simultaneously.

Trying it out with two different stands and liquid containers.

The camera pointing at both liquids. Because of the sqew of the wide angle lens, they had to be angled.