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All three simulators support PNG snapshots and WebM video recording. The Generator adds GIF export, fullscreen 1080p capture, and batch recording.

Export Comparison

FeatureGeneratorStencilMasked
Save PNGYesYesYes
Record WebMYesYesYes
Export GIFYesNoNo
Fullscreen 1080pYesNoNo
Batch RecordYesNoNo
Share URLNoYesNo

PNG Snapshot

Available in all three simulators via the Save PNG button.
  • File: shumi-physarum-{seed}.png
  • Resolution: Matches current canvas size
  • Best for: Static backgrounds, social posts, print-ready assets
Tip: Let the swarm grow 3–5 seconds before capturing for a fully developed network.

Stencil & Masked Compositing

In the Stencil and Masked, PNG capture composites all visible layers (background swarm, ghost afterimage, mascot physarum) into a single image. What you see is what you get.

WebM Video

Available in all three simulators via the ● Record button.
  • Codec: VP9 at 60 FPS (falls back to VP8 if unsupported)
  • Bitrate: 8 Mbps for high-quality output
  • File: shumi-physarum-{seed}.webm
  • Best for: Hero backgrounds, looping videos, social content
Click the button once to start, again to stop and download. Important (Generator): Set Cursor Influence to 0 before recording to avoid mouse interference.

Converting WebM to MP4

ffmpeg -i shumi-physarum-12345.webm -c:v libx264 -crf 18 output.mp4

Animated GIF (Generator Only)

The GIF exporter captures the live swarm, center-crops to a square, and encodes a looping animation.

Settings

SettingRangeDefaultNotes
Size128 – 720 px256pxSquare output, suitable for avatars
Duration2 – 15 seconds4sShorter = smaller file size
FPS8 – 3016Sweet spot 12–20

Size Guide

SizeUse Case
128 × 128Favicon, tiny embed, chat avatar
256 × 256Standard avatar, profile picture
480 × 480High-res profile, thumbnail
720 × 720Social media post, full-size asset

How to Export

  1. Let the swarm grow to a frame you like
  2. Set size, duration, and FPS
  3. Click Export GIF
  4. Wait for capture + encoding (progress shown)
  5. File downloads automatically

Fullscreen 1080p Recording (Generator Only)

Click Fullscreen Record (1080p) for 1080p output.
  • Hides the sidebar, resizes canvas to 1080 × 1080
  • Hub stays at 35% from top (designed for hero backgrounds)
  • Uses the clip length from the Recording Studio section
  • UI restores automatically when done
  • Best for: Website hero sections, presentations, brand assets

Recording Studio (Generator Only)

Seed Preview (Audition)

The fastest way to find your perfect swarm:
  1. Click Preview Seeds. Random seeds cycle every 4 seconds.
  2. Press Space to bookmark the current seed (max 10)
  3. Canvas border flashes green on bookmark
  4. Click Stop Preview when done
  5. Bookmarked seeds appear as clickable links

Batch Recording

After bookmarking seeds:
  1. Set Clip Length (5–60 seconds per seed)
  2. Click Batch Record Bookmarks
  3. Each seed records sequentially in fullscreen 1080p
  4. Files download one by one as each clip finishes

Share URL (Stencil Only)

The Stencil’s Share button copies a URL to clipboard that encodes the current seed, formation mode, and key stencil settings. See The Stencil for details on which parameters are encoded.

Browser Compatibility

FeatureChromeFirefoxSafariEdge
Live swarmYesYesYesYes
WebM recordingYesYesNo*Yes
GIF exportYesYesYesYes
OffscreenCanvas (Stencil Worker)YesYesNoYes
*Safari doesn’t support MediaRecorder with WebM. Use GIF export or screen recording instead.