Flow-field particles · minimax-m3

Let me start by exploring the current directory to understand what's there.

Good. I have the p5.min.js file. Now let me create a full-screen flow-field particle animation.

Plan:
- Use p5.js (global mode) for the animation
- 2000+ particles with Perlin noise vector field
- Fading trails using background fill with low alpha
- Color variation over time (HSL cycling)
- Particle recycling at boundaries
- Fixed-size trail history (or just no trail history, use bg fill for trail effect)
- Pause/Resume and Restart buttons
- Fit viewport (1200x800)

Implementation details:
- Use a noise field where particles sample direction by looking up noise(x*scale, y*scale, t*timeScale)
- To make it "evolve gradually", advance the z-coordinate of noise over time
- To recycle particles at boundaries, wrap them when they leave the canvas
- For trails: use background(0, fadeAlpha) each frame - this creates fading trail without ever-growing history
- For colors: cycle through HSL based on time or speed

Let me write the index.html now.

Now let me load it in the browser and check the output.

The animation is running, particles are visible, but the trail length is too short - I can see distinct dashes but they look more like static marks than flowing trails. The TRAIL_FADE of 18 is making them fade too fast, and the line length per frame might be too small. Also the colors look mostly magenta/red — the hue rotation isn't apparent yet (probably needs a few seconds).

Let me wait and check again, and also tune the trail fade. The issue is the field strength is small (2.2) and particles are moving slowly so trails are short. Let me also reduce the time advance so the noise doesn't drift too fast and let the trails build up.

Actually, looking at the screenshot again: the particles are moving, and there's clear local coherence (the dashes are pointing in similar directions within regions). The trails aren't very long because each frame's segment is short, and the fade is quick. Let me:
1. Lower TRAIL_FADE so trails persist longer
2. Increase FIELD_STRENGTH a bit
3. Verify with multiple frames

Now the trails are clearly visible — particles form flowing streams that follow coherent field directions, and colors are cycling (yellow/green/red shift visible across frames). The pattern is evolving over time too. The animation looks great.

Now let me test Pause/Resume and Restart.

Pause works — button changed to "Resume" and status shows "Paused". The trail structure is preserved. Now let me verify the screen doesn't change while paused (take a motion screenshot), then click Restart and verify trails clear and a new arrangement appears.

All four motion frames are pixel-identical, confirming Pause truly freezes the animation. Now let me click Restart and verify it clears trails and re-seeds.

Good — Resume works (button shows "Pause", status "Running"). The trails are continuing to evolve. Now let me click Restart.

Restart works — trails are completely cleared (background is fully black) and a brand-new particle arrangement is visible (small fresh dashes in cool blue/green/cyan colors), and the status label shows "Restarted". Let me wait a moment and take another screenshot to confirm trails start accumulating fresh and the new pattern differs from the previous one.

Excellent. After Restart, the trail pattern has been completely replaced with a new cool-palette (cyan/green/blue) arrangement — completely different from the warm yellow/red arrangement seen before. The four frames show the field evolving over time (stream patterns shift), trails are accumulating with fading behavior, and nearby particles clearly follow coherent local directions in flow-like streams.

All requirements verified:
- ✅ 2,400 particles (>2,000)
- ✅ Perlin-noise vector field with local coherence (visible flowing streams)
- ✅ Fading trails (clear gradient of trail history)
- ✅ Color variation over time (yellow→green→cyan→blue palette shift)
- ✅ Field evolves gradually (stream shapes differ across frames)
- ✅ Particle recycling at boundaries (some streams flow off-screen, no ever-growing population)
- ✅ Bounded population (PARTICLE_COUNT fixed)
- ✅ No per-particle trail history (uses background alpha fade)
- ✅ Pause/Resume works (verified canvas truly frozen)
- ✅ Restart clears trails and re-seeds (confirmed different palette & pattern)
- ✅ Full viewport, responsive at 1200×800

Everything works. The file is saved at index.html.