demiurg

Voxel asset editor for the roxlap voxel engine and the monada game framework.

Author voxel models and preview them rendered by the actual engine — the viewport is roxlap, so what you paint is byte-for-byte what the game shows. Save directly into the engine's formats. Native today; the browser/WASM build is designed but not yet shipped (one codebase, see DESIGN.md).

Status

v0.7.0 — model + skeletal-animation editor for artists. The native model editor (tools, selection + move + 90° rotate, palette, mirror, pivot, resizing, undo/redo, reference-image tracing, project save and engine-format export) plus a skeletal-animation editor — rig a model into bones (each built from one or more layers, sliced straight from a selection) and animate it with keyframes, posed in the viewport and exported to .rkc (DESIGN.md M2 + M4).

Animation is a preview: the .rkc format and the rig UI may still change. See Skeletal animation below. Voxel-video (.vvid, M5) follows. See the CHANGELOG.

Install

Pre-built Windows binaries are attached to each release. Download demiurg-<version>-windows-x64.exe and run it.

Build from source

The toolchain is pinned in rust-toolchain.toml (a nightly shared with roxlap for the future wasm-threads path; native builds behave like stable).

With Nix (provides the toolchain and the Linux render libs):

nix develop --command cargo run -p demiurg-app -- model.kv6

Or with a matching rustup toolchain (rustup auto-installs the pinned nightly):

cargo run -p demiurg-app -- model.kv6      # or no path for a blank canvas

On Linux the viewport needs the usual windowing/render libs (libxkbcommon, wayland, X11, vulkan-loader); the Nix devshell supplies them.

Usage

demiurg [path.kv6 | path.vox | path.demiurg | path.rkc]    # no path -> a blank canvas

• Tools 1–8: place, erase, paint, eyedropper, box, sphere, flood fill, select. Left mouse applies the tool; Ctrl+click eyedrops a colour.
• Select (8): click or drag a marquee; Shift adds, Alt removes. Drag a selected voxel's face to move the selection; Delete, Ctrl+C/Ctrl+V copy/paste, Esc deselects. The Rotate panel turns the selection 90° clockwise / counter-clockwise about a chosen axis.
• Camera: right-drag orbits, middle-drag (or Shift+right) pans, wheel / W/S zoom, Home recenters; the Views panel and numpad 1/3/7 snap to axis views (Ctrl for the opposite face).
• Edit: Ctrl+Z undo, Ctrl+Y / Ctrl+Shift+Z redo.
• Reference image: File ▸ Open reference image, drag a PNG/BMP/JPG/GIF/ TGA/WEBP onto the window, or paste one from the clipboard (Ctrl+V — e.g. copied from a browser) — pixel art becomes a flat 1-voxel-thick guide to trace from (non-destructive; place/scale/flip/hide it in the Reference panel). Dropping a .kv6/.vox/.demiurg opens it as the model (and a .rkc as a rig).
• Render: CPU renderer by default (reliable everywhere); --gpu (or ROXLAP_GPU=1) opts into the faster GPU backend, whose device creation can hang on some Windows GPUs/drivers (white frozen window). Switch sprite/voxel preview in the View menu.
• Open / recent: File ▸ Open loads any .demiurg / .rkc / .kv6 / .vox; File ▸ Open recent reopens a recently used file, and the file dialog remembers the last folder you used.
• Language: DEMIURG_LANG=ru, or the Language menu (English / Русский).

Skeletal animation (preview)

New in v0.5.0, and still a preview — the formats and UI may change. You build a rigged character (a skeleton of bones, each carrying its own voxel mesh), pose it across keyframes, and export to roxlap's .rkc format.

• Start a rig: File ▸ New rig (one root bone) or Convert to rig (wrap the current model as a one-bone rig). Opening a .rkc continues editing one.
• Rig sub-modes (Rig panel): Sculpt edits the active bone's mesh with the normal voxel tools (and "Extract to bone" / "Extract to layer" carve a selection out into a new child bone or a new layer on the same bone); Skeleton sets each bone's joint, parent, rotation axis and mesh pivot (drag a bone, or its pivot, in the viewport); Animate previews and poses the clip.
• Layers (Sculpt): a bone can carry several meshes — a base mesh plus extra layers, each sculpted on its own, named, and placed by its own offset (numerically or by dragging it against the posed bone).
• Posing (Animate mode): click a bone to select it, then left-drag in the viewport to transform it on the selected keyframe. R / G / S switch the gizmo between rotate (trackball / ring), move and scale.
• Timeline (bottom bar): Space plays / pauses; , and . step to the previous / next keyframe; buttons add, delete, copy, cut and paste keyframes; drag a tick to retime it.
• Clips (left panel): add, rename and delete animation clips, and set each clip's length and whether it loops.
• Export: File ▸ Export character writes a .rkc; a .demiurg project also stores the full rig.

Layout

demiurg-core    document model, edit commands, undo/redo, format conversion (no UI)
demiurg-i18n    UI message catalogue + translations (no_std, no deps)
demiurg-view    viewport: roxlap SceneRenderer bridge, orbit camera, picking
demiurg-app     native binary (winit + egui over the roxlap framebuffer)

Formats

• .demiurg — lossless editor project (the source of truth; stores a plain model or a full rig).
• .kv6 — engine sprite export (surface voxels; how monada draws pieces).
• .rkc — rigged-character export (skeleton + per-bone meshes + animation clips; roxlap's animated-character container). Preview — see above.
• .vxl — voxlap world export.
• .vox — MagicaVoxel import/export (single model; no pivot, so import centres it).

Dependencies

roxlap only — roxlap-formats, roxlap-render, roxlap-scene, roxlap-core (crates.io 0.13.0). No monada dependency. See DESIGN.md for the architecture and roadmap.

License

MIT OR Apache-2.0