framemill

Turn a rigged, animated 3D model into a directional 2D sprite sheet, driven by Blender in the background, wrapped in a small desktop app. No Blender knowledge required.

Point framemill at an animated .fbx / .glb / .gltf, choose how many directions and frames you want, pick a preset, and get a game-ready sheet. It is built for the "I have a Mixamo/Tripo model and want 8-direction sprites" workflow.

Why

Most 3D-to-sprite tools are Blender add-ons: you install them inside Blender and learn its UI. framemill is the opposite: a standalone GUI that runs Blender headless for you. The fiddly parts (consistent camera framing across an animation, high-quality Lanczos downscaling, sprite-sheet layout, legacy-engine TGA output) are handled for you.

Features

• Standalone desktop app (Windows / macOS / Linux). Blender runs in the background.
• Import FBX, glTF/GLB, OBJ; 1 / 4 / 8 / 16 directions; configurable frames and dimensions.
• Automatic preview, sprite/sheet views, instant direction switching, and playback.
• Direction order, row/column layout, loop or one-shot sampling, source-range trim, phase, reverse.
• Source-facing yaw, shared framing (fit or fixed world scale), anchors, and output offsets.
• Presets (Generic PBR, Tripo, Mixamo) plus full camera, lighting, and colour controls.
• Export dialog with a processed preview: PNG / TGA / BMP, 32/24/8-bit, alpha or colour-key backgrounds, edge bleed, dithering, custom palettes, and target presets.
• Versioned portable recipes and an optional JSON animation-metadata sidecar.
• A searchable in-app Help browser documenting every control.

Requirements

• Blender 4.2+ installed (framemill auto-detects it, or point it at the executable once). Blender is not bundled; install it from blender.org.
• For running from source: Python 3.10+.

Quick start

Install with pipx (Windows / macOS / Linux):

pipx install framemill
framemill            # launches the GUI

Update with pipx upgrade framemill. A Linux AppImage and the wheel/sdist are on the releases page. Prefer to run from source?

git clone https://github.com/ghreprimand/framemill
cd framemill
python -m venv .venv && source .venv/bin/activate   # Windows: .venv\Scripts\activate
python -m pip install -e .
framemill

Per-OS steps, update commands, and version pinning are in the installation guide.

Documentation

Detailed docs live in docs/:

The app also has a built-in Help browser (the Help button) with the same reference, searchable, covering every control.

Command line

framemill render walk.fbx -o hero --preset mixamo --angles 8 --frames 8 --format png,tga
framemill inspect walk.fbx

See the CLI reference for all commands and flags.

How it works

model.fbx ──> Blender (headless, render_sprites.py) ──> per-angle PNG frames
                                                              │
                                                     compositor.py (Pillow)
                                                     crop → Lanczos → tile
                                                              │
                                                    sheet.png / sheet.tga / .bmp

More detail in Architecture.

Contributing

See CONTRIBUTING.md for dev setup and testing notes.

License

framemill is free software licensed GPL-3.0-only. See LICENSE.

Copyright (C) 2026 Unfinished Works. You are free to use, study, share, and modify it. If you distribute it or a modified version, you must pass on those same freedoms under the GPL and make your source available; the GPL does not permit incorporating framemill into proprietary, closed-source software. (You can still charge for it; "free" here means freedom, not price.)

framemill is part of Unfinished Works.