Fizzualizer

A real-time audio visualizer for Linux (PipeWire) — 45 frequency-analyzed circles with collision physics, HSV color gradient, and optional particles.

This is a complete port of undefinist's Rainmeter Fizzualizer (an audio visualizer for the Windows desktop widget engine Rainmeter), rebuilt from scratch as a standalone Linux application. The original Lua physics, Rainmeter INI layout, and HSV colouring logic were translated to Python and OpenGL.

Built with AI — this entire project, from translating the Rainmeter Lua physics to debugging PipeWire audio capture and optimizing the GPU renderer, was developed entirely through conversation with an LLM-based coding agent (Hermes Agent). No human wrote a single line of the code directly.

Quick Start

Requires a Linux system with PipeWire and Nix (or nix-shell).

./run.sh

Or manually:

nix-shell shell.nix --command "python fizzualizer.py"

Dependencies (numpy, pygame, moderngl) are auto-resolved via the nix-shell.

How it works

1. Audio capture — pw-cat --record with the stream.capture.sink=true PipeWire property captures from the default speaker's monitor (system audio output, not the microphone). This is the same approach used by cava.

2. FFT analysis — 45 logarithmically-spaced frequency bands (10 Hz – 15 kHz) from a 2048-point real FFT, with attack/decay smoothing and per-band adaptive normalization so treble bands aren't drowned out by bass.

3. Collision physics — Two-pass collision detection (centre outward in both directions) ported directly from the Rainmeter Lua. Each ball is pushed away from overlapping neighbours and springs back to its rest position.

4. GPU rendering — All 45 circles drawn in a single OpenGL draw call via instanced quads (moderngl), reaching 60+ fps on integrated graphics.

5. HSV colouring — Balls sweep from blue (Hue 240) to purple (Hue 350), with saturation and value varying by band amplitude, matching the original skin's look.

Controls

Key	Action
Esc	Quit
F	Toggle fullscreen

Configuration

Edit config.py to adjust colours, ball size, spacing, sensitivity, particles, etc. All settings mirror the original Rainmeter Visualizer.ini variables.

Key ones:

Variable	Default	What it does
SENSITIVITY	55	Audio responsiveness (0-100)
NO_PARTICLES	True	Set False for bouncing particle effects
HUE_START	240	Colour gradient start (blue)
HUE_END	350	Colour gradient end (purple)
MAX_BALL_SIZE	200	Maximum ball diameter in pixels
SPACING_X	12	Horizontal spacing between balls
SPACING_Y	12	Vertical offset for staggered rows

Files

File	What
fizzualizer.py	Main app (~400 lines)
config.py	All visualizer settings
shell.nix	Nix environment (numpy, pygame, moderngl)
run.sh	Convenience launcher
@Resources/ + Visualizer.ini	Original Rainmeter source files (kept for reference)

Original

• Author: undefinist (Malody Hoe)
• Original skin: Fizzualizer on DeviantArt
• Rainmeter: rainmeter.net