Chladni Physics

Chladni Physics

Run a physics-based Chladni workflow. Always use the bundled script; do not write a new simulator from scratch.

Tool Call Contract

Call the shell tool directly. Do not print JSON command blocks, markdown plans, or a "Step 1" explanation before the first shell call.

First shell call for the default steel run:

python3 skills/chladni-physics/scripts/simulate_chladni_physics.py --out skill_output_<timestamp>_chladni-physics --preset steel-square-43 --palette blue-sand --size 1080 --frames 48 --fps 18 --particles 9000 --sand-steps 1800 --max-m 12 --max-n 12 --quiet

Second shell call:

find skill_output_<timestamp>_chladni-physics -maxdepth 3 -type f -print

Third shell call:

python3 - <<'PY'
import json
with open("skill_output_<timestamp>_chladni-physics/summary.json") as f:
    print(json.dumps(json.load(f), indent=2))
PY

The script solves a driven damped Kirchhoff-Love thin rectangular plate using a simply supported modal basis, then simulates sand particles drifting down the gradient of time-averaged acceleration energy. This is more physical than the fast chladni-plates visual skill, but it is intentionally limited to rectangular/square plates for reliability.

Required Workflow

1. Create or use an output directory, usually skill_output_<timestamp>_chladni-physics.
2. Choose a preset or explicit physical parameters.
3. Run scripts/simulate_chladni_physics.py.
4. Verify artifacts with find.
5. Read summary.json and report exact artifact paths, drive frequency, target mode, max displacement, max acceleration, and final particle node fraction.

Default command:

python3 skills/chladni-physics/scripts/simulate_chladni_physics.py \
  --out skill_output_<timestamp>_chladni-physics \
  --preset steel-square-43 \
  --palette blue-sand \
  --size 1080 \
  --frames 48 \
  --fps 18 \
  --particles 9000 \
  --sand-steps 1800 \
  --max-m 12 \
  --max-n 12 \
  --quiet

Presets

Use one of these values for --preset:

• steel-square-43: 30 cm steel square plate, excited near mode 4,3.
• glass-square-65: 24 cm glass square plate, excited near mode 6,5.
• aluminum-rectangle-27: 42 cm by 24 cm aluminum plate, excited near mode 2,7.
• brass-square-54: 28 cm brass square plate, excited near mode 5,4.
• custom: require explicit material, dimensions, target mode, drive point, and damping.

Main Parameters

Physical controls:

• --material: steel, aluminum, brass, glass, or acrylic.
• --youngs-modulus, --density, --poisson: optional material overrides.
• --length, --width, --thickness: plate dimensions in meters.
• --target-mode: mode used to choose the drive frequency when --drive-frequency is omitted.
• --drive-frequency: explicit drive frequency in Hz.
• --drive-ratio: drive frequency divided by target-mode frequency.
• --drive-x, --drive-y: forcing location as fractions of plate length and width.
• --force: harmonic force amplitude in Newtons.
• --damping: modal damping ratio.
• --max-m, --max-n: highest modal indices included.

Sand and rendering controls:

• --particles: number of sand particles.
• --sand-steps: particle transport steps.
• --particle-mobility, --particle-drag, --particle-noise: sand transport model.
• --grid: physics grid height.
• --size: output image height in pixels.
• --frames, --fps: GIF frame count and frame rate.
• --palette: blue-sand, copper, ice-fire, monochrome, or neon.
• --node-width: visual nodal highlight width.
• --skip-vibration-gif, --skip-sand-gif: omit expensive GIFs when needed.

Images and GIFs intentionally contain no rendered text. Titles and explanations belong in caption.txt, parameters.json, summary.json, and README.md.

Recipes

Steel square plate, mode 4,3:

python3 skills/chladni-physics/scripts/simulate_chladni_physics.py \
  --out skill_output_<timestamp>_chladni-physics \
  --preset steel-square-43 \
  --palette blue-sand \
  --size 1080 \
  --frames 48 \
  --fps 18 \
  --particles 9000 \
  --sand-steps 1800

Glass plate with cleaner presentation styling:

python3 skills/chladni-physics/scripts/simulate_chladni_physics.py \
  --out skill_output_<timestamp>_chladni-physics \
  --preset glass-square-65 \
  --palette monochrome \
  --size 1200 \
  --frames 48 \
  --fps 16 \
  --particles 10000 \
  --sand-steps 2200

Long aluminum plate:

python3 skills/chladni-physics/scripts/simulate_chladni_physics.py \
  --out skill_output_<timestamp>_chladni-physics \
  --preset aluminum-rectangle-27 \
  --palette ice-fire \
  --size 900 \
  --frames 48 \
  --fps 18 \
  --particles 8000 \
  --sand-steps 1800

Custom steel plate:

python3 skills/chladni-physics/scripts/simulate_chladni_physics.py \
  --out skill_output_<timestamp>_chladni-physics \
  --preset custom \
  --material steel \
  --length 0.32 \
  --width 0.24 \
  --thickness 0.0011 \
  --target-mode 5,4 \
  --drive-ratio 1.002 \
  --drive-x 0.36 \
  --drive-y 0.31 \
  --damping 0.006 \
  --palette neon \
  --size 960 \
  --frames 60 \
  --fps 20 \
  --particles 10000 \
  --sand-steps 2400

Outputs

The script writes:

• chladni_sand_pattern.png: final simulated sand accumulation.
• sand_settling.gif: sand migration movie.
• plate_vibration.gif: driven plate displacement movie.
• vibration_amplitude.png: time-averaged vibration amplitude.
• displacement_snapshot.png: displacement at phase zero.
• frames/sand/frame_*.png: sand settling frames.
• frames/vibration/frame_*.png: plate vibration frames.
• modal_frequencies.csv: modal frequencies, drive coupling, amplitudes.
• physics_data.npz: response fields and final particle coordinates.
• parameters.json: exact input parameters and artifact paths.
• summary.json: key physical results.
• caption.txt: short explanation.
• README.md: run summary.

Do not claim success unless find lists the requested PNGs, GIFs, frame directories, modal_frequencies.csv, physics_data.npz, parameters.json, summary.json, caption.txt, and README.md.