A voxel editor with a path tracer and an MCP server, written in Rust.
macOS, Windows, Linux, FreeBSD, Android, and iOS.
Download · MCP · Scripting · Bridges · Command line · Build
Froxel opens and saves MagicaVoxel .vox files, edits them with brushes, shapes,
and selections, path-traces them on the GPU, and exports glTF with bones and
animation clips. An AI agent can drive all of it through the built-in
Model Context Protocol server.
.voxin and out. Keeps groups, layers, hidden objects, animation frames, and materials (_diffuse,_metal,_glass,_emit). Files saved by Froxel open in MagicaVoxel.- Editing. Brush, line, circle, square, box, face fill, generators, mutators, marquee, box select, and flood select. Add, remove, and paint modes. Object mode moves, rotates, mirrors, and flips whole objects. Each stroke undoes in one step.
- Characters. Bones, rigid binding of objects to bones, poses, and animation
clips, saved in the
.voxfile and exported to glTF. - Render mode. A path tracer with sky, sun, metal, glass, and emission. It accumulates on the GPU through wgpu (Metal, Vulkan, DX12) and falls back to the CPU. Denoising is built in.
- glTF export.
.glbwith merged coplanar faces, no T-junctions, and a palette texture or vertex colours. - Mesh import. A
.glb,.gltf, or.objsculpted in Blender or made by an image-to-3D tool, voxelized solid or as a shell at a cell count or a voxel size in metres, its texture and vertex colours quantized into the palette. - Scripts. Objects can carry a sandboxed Rhai script with sliders for its parameters.
- Bridges. Godot and Blender can drive those sliders and import the mesh live, then bake a standalone scene. See docs/bridges.md.
- Automation. An MCP server for agents and a command line for batch renders.
Download the file for your system from the latest release.
| System | File | Notes |
|---|---|---|
| macOS 11+ (Apple silicon and Intel) | froxel-<version>-macos-universal.dmg |
Signed and notarized. Drag Froxel to Applications. |
| Windows (x64, x86, ARM64) | froxel-<version>-windows-<arch>.zip |
Not signed yet (why). SmartScreen may ask once: choose More info → Run anyway. Windows 11 with Smart App Control on blocks it outright. |
| Debian, Ubuntu (x86_64, aarch64, riscv64) | froxel-<version>-linux-<arch>.deb |
sudo apt install ./froxel-*.deb adds the menu entry and icon. Needs Vulkan. |
| Other Linux | froxel-<version>-linux-<arch>.tar.gz |
Needs Vulkan and glibc 2.35 or newer (2.39 for riscv64). |
| FreeBSD (x86_64) | froxel-<version>-freebsd-x86_64.tar.gz |
|
| Android 7.0+ (arm64) | froxel-<version>-android-arm64.apk |
Open it on the phone. Android asks once to allow installs from the browser or file manager. |
| iOS 16+ simulator | froxel-<version>-ios-simulator.zip |
Unzip and drag Froxel.app onto a booted simulator. The device build goes to the App Store. |
| Godot 4.3+ plugin | froxel-<version>-godot-addon.zip |
Unzip into the project folder. See Godot and Blender. |
| Blender 4.2+ add-on | froxel-<version>-blender-addon.zip |
Preferences → Add-ons → Install from Disk. |
Every release has a SHA256SUMS.txt. How the builds are signed is in
CODE_SIGNING.md.
Try it on the frog, examples/frog.vox, or on the scripted
lily pad, tests/fixtures/examples/lily_pad.vox.
The Android and iOS builds are the same editor with a touch layout. The viewport fills the screen. The strip at the bottom holds the tool, add, remove, and paint, the colour, and undo. The tool settings, the palette, and the files open as sheets above it. The bundled frog and lily pad are under the folder button, and your own files are saved to the app's documents.
- One finger uses the active tool.
- Two fingers orbit and pinch to zoom. Three fingers pan.
- Long-press the colour, then tap a voxel, to pick its colour.
On a tablet 700 points wide or more, the desktop tools and palette sit on the left instead of the strip.
- Right-drag orbits. Scroll zooms. Space-drag or middle-drag pans.
- Left-drag uses the active tool.
- V brush, L line, B box, F face, U mutator, M marquee.
- T add, R remove, G paint. These three apply in Model mode.
- Tab switches Model and Object mode.
- In Object mode, X / Y / Z rotates the active object. Shift flips it.
- ⌘Z / ⇧⌘Z undo and redo. ⌘C / ⌘X / ⌘V copy, cut, and paste.
- ⌘N / ⌘O / ⌘S / ⇧⌘S new, open, save, and save as.
- ⇧⌘E exports a glTF
.glbwith a palette texture and merged faces.
On Windows and Linux, use Ctrl in place of ⌘.
froxel mcp is a Model Context Protocol server.
An agent can create objects, place voxels, fill boxes and ellipsoids, set the
palette, add bones and clips, run scripts, export .glb, and path-trace a PNG
to check its work. The frog in these pictures was built this way.
Add it to Claude Code. On macOS, after installing from the dmg:
claude mcp add froxel -- /Applications/Froxel.app/Contents/MacOS/froxel mcpAlso install the agent skill, skills/froxel/SKILL.md,
which tells the agent when and how to use the tools (block out, preview after
every step, fit to reference views). Adding the server does not install it:
copy the skills/froxel folder into ~/.claude/skills/, or without a clone:
mkdir -p ~/.claude/skills/froxel && curl -fsSL https://raw.githubusercontent.com/theromis/Froxel/main/skills/froxel/SKILL.md -o ~/.claude/skills/froxel/SKILL.mdOr add it to any MCP client's config:
{
"mcpServers": {
"froxel": {
"command": "/path/to/froxel",
"args": ["mcp"]
}
}
}Then ask for a model:
Build a 16-voxel-tall voxel frog with big eyes and pink cheeks, give it a head and jaw bone, render it from the front, and export it to
frog.glb.
froxel mcp works headless, with no window. To watch the edits happen, and let
the agent take screenshots and click controls, connect it to an open editor:
froxel mcp --connect 127.0.0.1:7979 --launch--launch opens the window if it is not already running. The full tool list and
the connected mode are in docs/mcp.md.
Creatures and other one-off shapes are made by hand sculpting: block out with box and ellipsoid fills, refine single cells, render after every step, and compare with the reference. No script is stored. See docs/hand-sculpting.md.
An object can carry a Rhai script. The editor shows a slider
for each parameter, and Regenerate rebuilds the voxels. Scripts run in a
sandbox with no file, network, or clock access, and saved files keep the voxels,
so the .vox still opens in MagicaVoxel.
let radius = param_float("radius", 8.0, 3.0, 16.0);
let seed = param_int("seed", 1, 0, 9999);
set_slot(1, [18, 72, 28]); // a palette colour
// …for each cell inside a wobbly disc:
set(ix, 0, iz, slot);The whole lily pad is tests/fixtures/examples/lily_pad.rhai.
Scripts also have the hand-sculpting tools (tubes, carving, smoothing, breaks,
and debris); tests/fixtures/examples/hollow_log.rhai uses all of
them, and tests/fixtures/examples/fallen_tree.rhai shapes a
fallen tree with loft, deform, and brush. The API is in
docs/scripting.md.
froxel bridge serves a .vox on 127.0.0.1. A Godot node or the Blender
sidebar connects with the printed session file, shows a slider for each script
parameter, and imports the model as glTF, bones and clips included. Moving a
slider reruns the script. Bake writes an ordinary scene or Blender object
that no longer needs Froxel, and headless Godot can bake a list of variants in
one go. --bridge PORT serves the open editor instead, so edits in the window
show up in the next import.
froxel bridge --input tests/fixtures/examples/lily_pad.vox # four sliders: radius, notch, direction, seed
froxel --bridge 29771 tests/fixtures/examples/lily_pad.vox
The Godot plugin is godot/addons/froxel_bridge and
the Blender add-on is blender/froxel_bridge. Both are
in every release since 0.2.0 as froxel-<version>-godot-addon.zip and
froxel-<version>-blender-addon.zip. Tested with Godot 4.5 and Blender 5.2.
Setup, the variant baker, and the protocol are in docs/bridges.md.
froxel render path-traces a .vox file to a PNG with no window. The CPU tracer is
the default, so a given seed always writes the same image. --gpu uses the wgpu
tracer.
froxel render --input examples/frog.vox --output frog.png \
--width 1440 --height 810 --samples 256 --denoise --gpu \
--yaw -62 --pitch 16 --distance 0.72That command made this picture. --help lists every option: camera,
depth of field, sky, sun, glass mode, and albedo and normal passes. The turntable
above is 48 such renders, one every 7.5° of --yaw.
froxel preview draws the same .vox as the edit viewport lights it,
rasterised on the CPU in a fraction of a second, fitted to the model (or
--object) with a margin. docs/preview.md has the
flags; MCP preview is the same image. --preset game is the gameplay
camera (orthographic, yaw −135, pitch 32; --presets redefines it for a
project, --placement-yaw sees an asset placed turned), and several --input files,
--variants, or a --reference concept make a labelled contact sheet.
--lighting old_pond (or a preset of your own) lights it with a game's
sun, ambient, and grade instead of the viewport light. It prints two
triangle counts: the unmerged mesh it draws, and what
froxel export writes with the export flags given (--merge,
--color-atlas).
froxel preview --input model.vox --out preview.png --yaw -35 --pitch 30 --width 1600 --height 800froxel compare --input model.vox --concept sheet.png --crop 40,60,520,300 --view front --ortho --out vs.png scores the model's silhouette against a
concept view: it prints IoU, the share of the concept missing, and the
share of the model in excess, and writes an overlay with the concept's
outline and both in colour. froxel carve --views views.json --out model.vox fills the visual hull of a turnaround sheet's front, side, and
top views, and froxel paint --args paint.json --input model.vox --out painted.vox recolours the surface one view sees from a single image (a
shell's plates from the top). froxel fit --args fit.json --input blockout.vox --out fitted.vox refines a blockout so its orthographic views
match the sheet's, with colours from its palette slots, and prints each
view's IoU and colour error before and after. froxel optimize --args optimize.json --input blockout.vox --out fitted.vox iterates a small
creature (20 to 60 cells) until its views match its pixel-art views, shape
and colours together, and prints each view's agreement before and after;
built with --features clip-metal, its semantic option adds a CLIP
patch-similarity term on Apple Metal (weights downloaded separately; see
docs/mcp.md).
MCP compare_silhouette, carve_from_views, project_paint,
fit_to_views, and optimize_to_views are the same; see
docs/mcp.md.
froxel compare --input log.vox --concept log-sheet.png --crop 40,60,520,300 --view front --ortho --out log-vs-front.pngfroxel export --input model.vox --output model.glb writes the glTF with
the export_mesh options as flags: --merge, --vertex-colors,
--color-atlas, --export-hidden, --split-objects, and --ao STRENGTH
with --ao-radius CELLS and --ao-target vertex|texture|both for baked
ambient occlusion in COLOR_0 or the colour atlas. --bake JSON|FILE with
--color-atlas paints ray-traced occlusion and a sun with shadows into the
atlas, for a game to draw unshaded; froxel preview --input model.glb looks at
the written file. froxel bake-scene --scene scene.json --output level.glb bakes
a placement of many .vox files together, each shaded by its neighbours and by
ground, into one mesh with one atlas (tests/fixtures/examples/stacked_blocks_scene.json).
froxel export --input ruins.vox --output ruins.glb --merge --ao 0.8 --ao-radius 3
froxel export --input ruins.vox --output lit.glb --color-atlas --bake '{"preset": "old_pond", "distance": 12}'froxel import --mesh tree.glb --output tree.vox --voxel-size 0.08 voxelizes
a mesh with the MCP import_mesh options as flags (--size, --scale,
--z-up, --rotation, --position, --anchor, --shell, --slots,
--max-new-slots, --tolerance, --input for a document to add to,
--new-object) and prints the report: cells, slots, and bounds.
froxel variants --input wall.vox --variants sets.json --out variants/
bakes a scripted document once per parameter set in sets.json (a list of
{"name": "low", "params": {"height": 12}}) and writes low.vox,
low.glb, and a variants.json manifest of each set's parameters,
markers, and bounds; it takes the froxel export mesh flags and
--no-vox. Exporting again into the same folder updates the manifest by
variant name, so a subset can be redone without dropping the others;
--replace writes it fresh. MCP export_variants and the Export panel's Export
variants… do the same.
froxel voxrt --input model.vox loads a file, saves it, loads the save, and
checks that nothing changed: objects, palette, materials, scene graph, bones,
scripts, and motion. --dump prints the chunk tree instead.
You need Rust. On Linux, the editor loads Wayland or X11 and
Vulkan at run time, so the build needs no -dev packages.
git clone https://github.com/theromis/Froxel
cd Froxel
cargo run --release -- examples/frog.voxThe binary is target/release/froxel. On macOS the File and Edit commands live on
the application menu bar. Elsewhere, or with FROXEL_NO_NATIVE_MENU set, they are
in a menu strip at the top of the window.
--features oidn links Open Image Denoise for
--denoise. It needs the library on the build machine. Without it, Froxel uses
its built-in edge-aware filter.
--features clip-metal (or clip on the CPU) adds the CLIP semantic term of
optimize_to_views through candle. It
reads OpenAI's CLIP ViT-B/32 weights (MIT licence, about 605 MB), which are
not bundled: download model.safetensors of openai/clip-vit-base-patch32 to
~/Library/Application Support/Froxel/models/clip-vit-base-patch32.safetensors
(or point FROXEL_CLIP_MODEL at it). The default build has no CLIP.
The phone builds need the Android NDK and cargo-apk, or Xcode on macOS:
cargo apk build --lib --features android-lib --release # target/release/apk/froxel.apk
packaging/android/bundle.sh # Play bundle, froxel.aab (needs a JDK)
packaging/ios/bundle.sh # simulator Froxel.appTests:
cargo test --bin froxelWhat changed in each version is in CHANGELOG.md. Releases are built by a GitHub workflow. See docs/releasing.md.
Inspired by MacVoxel.
MIT. See LICENSE.