User Guide
Interface overview
OrcaWeb is a three-step workflow: Model → Settings → Slice.
Model tab
Upload your model by dragging it onto the drop zone or clicking to browse. Supported formats: STL (ASCII and binary), 3MF, STEP (.step/.stp, tessellated by OCCT built into the slicer engine — no extra download), and OBJ.
- Rotate: left-drag
- Pan: right-drag / Ctrl+drag
- Zoom: scroll wheel
The 3D viewer shows the model on a virtual print bed sized to match the currently selected printer (e.g. 256×256 mm for Bambu Lab, 250×210 mm for Prusa MK4).
3MF files
When you load a .3mf file, OrcaWeb automatically:
- Extracts the mesh geometry and converts it to binary STL for the slicer
- Reads any OrcaSlicer profile metadata bundled inside the archive (
Metadata/*.json/.config) - Merges the embedded settings — printer model, nozzle diameter, bed size, filament temperatures, process parameters — on top of your current overrides, and shows a notice telling you how many settings were applied
If the 3MF contains a machine profile with a printable_area field the bed visualisation updates to match.
OBJ files
When you load a .obj file, OrcaWeb converts it to binary STL using OrcaSlicer's own C++ parser (objparser.cpp) compiled into the WASM engine — the same code used by OrcaSlicer desktop.
- Supported: triangulated meshes, quad faces (auto-triangulated), multi-object files (merged into one)
- Not supported: NURBS / curves, MTL material files (geometry only — colors are ignored for slicing)
- Conversion happens in the Web Worker; no extra WASM download required (reuses the slicer engine)
STEP files
When you load a .step or .stp file, OrcaWeb uses Open CASCADE Technology (OCCT 7.8.1) compiled directly into the slicer engine to tessellate the CAD geometry into a triangle mesh, then converts it to binary STL.
- No extra download — OCCT is part of
slicer.wasm - Conversion runs in the slicer Web Worker alongside OBJ and STL processing
- IGES (
.iges/.igs) is not supported — OrcaSlicer's STEP reader (STEPCAFControl_Reader) does not read IGES
Settings tab
Configure the print before slicing.
Printer
Choose a preset printer or select Generic 0.4 / Generic 0.6 for a standard setup. The selected printer determines the bed size shown in the 3D viewer and used for model centring during slicing.
| Preset | Bed size |
|---|---|
| Generic 0.4 / 0.6 | 256 × 256 mm |
| Bambu Lab P1S | 256 × 256 mm |
| Bambu Lab X1C | 256 × 256 mm |
| Creality Ender 3 | 220 × 220 mm |
| Prusa MK4 | 250 × 210 mm |
| Voron 2.4 | 300 × 300 mm |
You can also load a 3MF file from OrcaSlicer to pull in the exact bed dimensions from your slicer project.
Filament
Select the material type; nozzle and bed temperatures update automatically.
| Material | Nozzle | Bed |
|---|---|---|
| PLA | 220°C | 60°C |
| PETG | 240°C | 80°C |
| ABS | 255°C | 100°C |
| TPU | 230°C | 50°C |
Quality preset
| Preset | Layer height | Use case |
|---|---|---|
| Draft | 0.3 mm | Fast prototypes |
| Standard | 0.2 mm | Everyday prints |
| Fine | 0.1 mm | Detail parts |
Infill
Adjust density (0–100%) and pattern. Available patterns: grid, gyroid, honeycomb, triangles, cubic, lightning, rectilinear.
Supports
Enable auto supports. Supported types: normal(auto), normal(manual), tree(auto), tree(manual).
Advanced settings
Click Show advanced settings for:
- Speed overrides (default, outer wall, first layer, travel)
- Seam position
- Fuzzy skin (surface roughness)
- Ironing (top surface)
Fuzzy skin
Adds random noise to the outer perimeter to give models a rough, organic texture instead of smooth walls.
| Option | Effect |
|---|---|
| None | Standard smooth walls (default) |
| External | Applies noise to outer walls only |
| All | Applies noise to all walls (outer + inner) |
When fuzzy skin is enabled two extra fields appear:
- Thickness (0.05–2 mm, default 0.3 mm) — amplitude of the noise; larger values = rougher texture
- Point dist (0.1–5 mm, default 0.8 mm) — spacing between noise sample points along the wall; smaller values = denser, finer pattern
The noise is generated by libnoise compiled into the WASM engine (Perlin, Billow, RidgedMulti, and Voronoi waveforms are all active).
Settings you changed yourself
Any field you edit by hand is marked with an amber outline and a small reset button, and a line at the top of the panel counts how many there are.
Those edits are the highest-priority layer: they stay put when you switch printer, filament or quality preset, and when you load another 3MF or profile. Only the fields you never touched follow the newly selected profile. To go back to a profile's own value, use the field's reset button, or Reset all at the top of the panel.
The full order — preset, then imported file, then your edits — is described under Settings precedence.
Importing an OrcaSlicer profile
Click Import OrcaSlicer profile (.json) to load settings from any desktop OrcaSlicer profile file. The app shows how many settings were imported and applies them on top of the current preset — but below anything you edited by hand.
Alternatively, load a 3MF file — profiles embedded in the archive are extracted automatically (see Model tab above).
Settings (printer, filament, quality preset, and any overrides) are saved in your browser's local storage and restored on the next visit.
Slice tab
Each uploaded file appears as a queue item. Click Slice (or Slice All) to slice every ready file one after another:
- The STL is passed to the Web Worker running OrcaSlicer WASM
- Slicing takes ~50–500 ms for small models, up to minutes for complex ones
- Each finished card shows the print time, filament use, and layer count, plus Download and an eye icon that expands a side-by-side preview:
- Model — your original STL on the print bed
- G-code — rendered toolpaths with a layer slider
While a slice is running a Cancel button appears — cancelling restarts the slicer engine, so the next slice reloads it (from cache, a few seconds).
With two or more ready files, One plate arranges them all on a single bed and produces one combined G-code file, and Download All (.zip) bundles every finished G-code into a single ZIP archive.
Changing settings after slicing
If you change any setting after a file was sliced, its result is marked "Sliced with previous settings" and the Slice button turns into Re-slice — the previous G-code stays downloadable until you re-slice.
G-code viewer
- Feature-type colours — when the G-code contains OrcaSlicer
;TYPE:(generic flavor) or; FEATURE:(Bambu flavor) comments each feature type (outer wall, inner wall, infill, support, bridge, etc.) is rendered in a distinct colour. A legend overlay in the top-right corner shows the colour key. - Layer detection — layers follow the engine's
;LAYER_CHANGE/; CHANGE_LAYERmarkers, so spiral/vase-mode prints and Z-hop moves are displayed correctly; G-code without markers falls back to grouping by Z height. - Arc moves —
G2/G3arcs (arc-fitting profiles) are tessellated and rendered like ordinary moves. - Height gradient — plain G-code without feature comments is coloured blue (bottom) → orange (top).
- Thick extrusion lines — rendered with
LineSegments2+LineMaterial(1.6 px screen-space width) for a solid, 3D-looking result. WebGL'slinewidthis ignored above 1 px on most drivers. - Travel moves — non-extruding rapid moves are shown as dim grey lines when the Travels toggle in the control bar is on (off by default).
- Layer cursor — a semi-transparent plane marks the height of the currently selected layer.
- Use the Layer slider to scroll through from bottom to top.
- The layer counter shows current layer / total layers and the Z height.
G-code statistics
Each finished queue card shows key metrics parsed from the G-code output:
| Stat | Source |
|---|---|
| Print time | ; total estimated time / ; model printing time (Bambu flavor) or ; estimated printing time = comment |
| Filament | ; filament used [g] comment, falling back to ; filament used [mm] |
| Layers | ; total layer number comment |
Stats are searched in the head and tail of the G-code file, as OrcaSlicer writes them in both locations.
Downloading G-code
Click Download on a queue card to save that file's output as
<filename>.gcode. With several finished files, Download All (.zip)
saves them together as one ZIP archive.
Performance notes
- WASM loads once per browser session (~10–30 s on first visit depending on connection, then cached)
- Slicing a small model (10 mm cube): ~150 ms
- Slicing a complex model (500k triangles): ~2–5 s
- Slicing runs single-threaded in your browser session unless you're on a cross-origin-isolated deployment (currently the Cloudflare mirror), where a multithreaded engine variant is used transparently for a speed-up on complex models — see the ST vs MT benchmark. Either way, no action is required on your part; the app selects the right engine automatically.