Gcode Viewer

A standalone 3D G-code viewer for Linux, written in Rust with egui and wgpu. Open a .gcode file and orbit the toolpath, scrub through layers and switch between fast flat lines and lit, shadowed rendering.

Features

• 3D toolpath with orbit, pan and zoom camera
• Navigation cube: drag to orbit, or click a face, edge or corner to snap to that view
• CAD style number key views and an orthographic projection option
• Layer range sliders (top and bottom layer), with a play button that animates the print layer by layer
• Colour by height, speed, layer, feature type (from ;TYPE: and ; FEATURE: comments) or filament (tool changes, using the slicer's filament_colour)
• File statistics: print time (when the slicer reports it), extrusion and travel move counts, travel distance, tool changes and M600 pauses, plus filament used per tool
• Optional travel move display
• Three render modes: Fast (flat lines, best for large models), Shaded, and Shaded with shadows
• Adjustable light direction and height
• Parses G0/G1 moves, G2/G3 arcs, relative and absolute positioning and extrusion, and G92 resets
• File manager integration: default opener for .gcode, a file type icon, and thumbnails taken from the preview image your slicer embeds in the file

Build requirements

• Rust (stable, edition 2024)
• A Vulkan capable GPU and driver
• On Fedora: sudo dnf install rust cargo libxkbcommon-devel wayland-devel

Build and run

cargo run --release -- path/to/file.gcode

You can also run it without arguments and use "Open file…", or drop a file onto the window.

Install

./scripts/install.sh

This builds the project and installs:

• ~/.local/bin/gcode-viewer
• a desktop entry, app icon and .gcode file icon under ~/.local/share
• a MIME definition for text/x.gcode, and sets Gcode Viewer as its default application

Thumbnails

./scripts/install.sh --all

--all also installs the thumbnailer. GNOME runs thumbnailers in a sandbox that can only see /usr, so the gcode-thumbnailer binary is installed to /usr/local/bin with sudo, and you will be prompted for your password. Restart your file manager afterwards (nautilus -q) so it picks up the new thumbnailer.

Thumbnails only appear for files that contain an embedded preview image (PrusaSlicer, OrcaSlicer and ElegooSlicer all write one).

The thumbnailer flattens the preview onto white and adds a small GCODE label in the top right corner, drawn with the bundled Liberation Sans font (assets/, SIL Open Font License).

Controls

Input	Action
Left drag	Orbit
Right or middle drag	Pan
Scroll	Zoom
Navigation cube	Drag to orbit, or click a face, edge or corner to snap to that view
1 / 3 / 7	Front / right / top view (hold Ctrl for back / left / bottom)
2 / 4 / 6 / 8	Step orbit by 15 degrees
9	Flip to the opposite side
5	Toggle perspective and orthographic projection
0	Reset the view
Space	Play or pause the layer animation
C	Cycle the colour mode

The number keys work on both the top row and the numpad.

Limitations

• Layers are detected by Z changes on extruding moves, so vase mode prints show as a single layer
• The whole file is read into memory
• Shaded modes draw every extrusion as geometry and can be slow on very large files, use Fast mode there

License

GPL-3.0-only. See LICENSE.