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08 · Tutorial · 7 min read

Exporting Your Work

Smart PNGs, bucket renders, 4K video, and mesh export.

Smart PNG snapshots

The fastest way to capture a render — click the camera icon in the top bar. GMT saves a PNG of the current view to your Downloads folder.

Every PNG is a complete scene file. The full GMF scene data is invisibly embedded in the image's iTXt metadata chunk. Drop the PNG back into GMT (onto the app window or via System Menu → Load Preset) and the entire scene reopens exactly — camera, formula, lighting, all of it.

Share direct file downloads (Discord, email, cloud storage) to preserve the embedded data. Social media platforms (Twitter, Facebook, Instagram) strip metadata — the image will look fine but won't restore the scene.

High-quality still renders (bucket mode)

For production-quality images, click the grid icon in the top bar. This is GMT's bucket renderer — the image is rendered in tiles, each accumulating until clean, then saved out.

Two modes:

  • Refine View — converges the current viewport without saving. Good for reviewing a clean version.
  • Export Image — renders at scaled resolution and downloads a PNG.

Controls:

  • Convergence Threshold — how similar consecutive samples must be before a tile is "done." 0.1% for production, 1% for fast preview.
  • Export Scale — 2× turns 1080p into 4K; 4× makes 8K.
  • Bucket Size — smaller tiles use less VRAM, larger tiles render faster.
  • Max Samples Per Bucket — safety cap, default 64.

All post-processing (bloom, chromatic aberration, color grading, tone mapping) runs on the final assembled image — so the output matches the live viewport exactly.

Video export

First set up an animation in the Timeline. Then click the Render button in the Timeline toolbar.

Settings

  • Resolution — built-in presets for 720p up to 4K, plus social formats (1:1 square, 4:5 portrait, 9:16 vertical for Instagram/TikTok)
  • Bitrate — file size / compression quality tradeoff. 12–20 Mbps is enough for 1080p.
  • Samples per frame — 16–32 for draft, 64–128 for production (no visible grain)
  • Internal Scale (SSAA) — renders each frame at higher-than-output resolution and downscales. Kills aliasing on fractal detail.
  • Start / End Frame — render a subset of the animation
  • Frame Step — skip frames for fast preview (step 2 = every other frame)

Disk vs RAM mode (browser-dependent)

  • Chrome / Edge / Opera — Disk mode. You choose where to save before the render starts; frames stream directly to disk. Any file size.
  • Firefox / Safari — RAM mode. The entire video buffers in memory, written at the end. Tab will crash on videos larger than ~2 GB. For long 4K renders, split into shorter segments.

Interrupt and resume

You can pause a render mid-way, resume later, or Finish Early to encode whatever's done so far into a shorter video. Useful when you realize the animation's longer than you meant it to be.

Scene files (.gmf)

For compact sharing (e.g. Reddit posts, text-based forums), save a .gmf file instead of a PNG: System Menu → Save Preset. It's a plain text file containing the formula's GLSL and the full scene state — usually a few KB to a few tens of KB.

To load someone else's .gmf: drop it onto the app window or System Menu → Load Preset.

URL sharing

System Menu → Copy Link encodes the scene into a URL (about 4KB max). Fast for sharing in chat, but won't work for custom/imported formulas (shader too big). Complex animations may have keyframes auto-stripped to fit — a warning appears if that happens.

Mesh export (STL, VDB)

For 3D printing or importing into Blender / Houdini / Maya, open the Mesh Export tool from the System Menu. GMT extracts a watertight mesh from the current scene.

  • STL — standard triangle mesh. Every 3D printer slicer accepts it.
  • VDB — volumetric format, preserves internal structure. For Houdini FX and high-end VFX workflows.

The preview canvas shows what will be exported before you commit. Mesh extraction is heavy — start with a coarse resolution to preview, then increase for the final export.

Not every scene meshes cleanly. Some formulas have infinite detail that confuses the mesher; others have non-watertight surfaces. The tool flags problematic regions — use the bounding box controls to crop to an area that meshes well. For deep infinite detail, sub-sampling the DE (distance estimator) helps.

A quick export decision tree

  • Fast share of what I see right now → camera icon (PNG snapshot)
  • Print-quality still image → bucket render → Export Image
  • Text-only scene share → Copy Link or Save Preset (.gmf)
  • Short video clip → Timeline → Render (RAM mode on Firefox, Disk on Chrome)
  • 4K+ video → Chrome/Edge only → Disk mode → be patient
  • 3D print → Mesh Export → STL, preview first, crop with bounds if needed