These controls define the liquid your bubbles exist within and the physical space they resonate inside. Together they shape the fundamental tonal character of FOAM.
Material Presets
The Material dropdown provides scientifically-accurate liquid presets. Each one sets density, surface tension, and viscosity to real measured values.
| Material | Character |
|---|
| Custom | Manual control of all three liquid parameters |
| Water | Bright, crisp pops — the reference liquid |
| Seawater | Slightly denser, the default starting point |
| Soap Solution | Lower surface tension, longer-lived bubbles |
| Glycerol | Thick, gloopy, slow decay |
| Honey | Very viscous, muted and heavy |
| Olive Oil | Medium viscosity, organic warmth |
| Mercury | Extreme density, unusual resonance |
| Ethanol | Light, low surface tension |
| Molasses | Most viscous, almost percussive thuds |
Manual Liquid Controls
When Material is set to “Custom” you have direct control. (These knobs are visible in all modes; selecting a preset overwrites them.)
| Knob | What It Does |
|---|
| Liquid Mass | Density of the liquid (600-14000 kg/m³). Higher density = slightly lower pitch and different damping character. |
| Tension | Surface tension (0.02-0.5 N/m) affects how bubbles form and burst. Low tension = fragile, quick pops. High tension = more crystalline ring. |
| Viscosity | How “thick” the liquid is (0.0003-12 Pa·s). Low viscosity (water) gives quick, bright decay. High viscosity (honey) gives slow, muffled decay. |
Resonator
The Resonator dropdown applies a physical-space body resonance to all bubbles passing through it — as if the entire foam were happening inside a glass jar, a metal pipe, a cave, or your skull. Each preset is a multi-mode bandpass filter modeled on the real physics of that space.
| Preset | Character |
|---|
| None | Bypass — no resonance applied |
| Glass Jar | Bright, ringing — Helmholtz fundamental + cylindrical cavity modes (~280 Hz) |
| Metal Pipe | Perfectly harmonic, medium decay — open-open tube (~170 Hz) |
| Ceramic Bowl | Inharmonic shell modes, warm and rounded (~520 Hz) |
| Bathtub | Dense, boomy — rectangular room modes (~113 Hz) |
| Underwater | Deep, muffled — water column resonance, heavy damping (~65 Hz) |
| Seashell | Airy, whispery — Helmholtz + spiral cavity (~380 Hz) |
| Metal Bucket | Harsh, clangy — high-Q metal shell (~210 Hz) |
| Cave | Massive, infrasonic — large irregular room with very long decay (~17 Hz) |
| Cistern | Extremely long decay, like Fort Worden — tall stone cylinder (~28 Hz) |
| Well | Quarter-wave tube, odd harmonics dominant (~8.5 Hz) |
| Skull | Formant-like resonances modeled on bone conduction (~200 Hz) |
| Knob | What It Does |
|---|
| Resonance | Wet/dry mix amount (0-100%). At 0% the resonator is bypassed even if a preset is selected. |
In Melodic and Harmonic Flow Types, the resonator’s pitch tracks the lowest active MIDI note — turning the body resonance into a tunable instrument rather than a fixed character.
The Resonance amount knob is included in Chaos modulation, so right-click to lock it if you want a stable resonance while everything else moves.
