floorplan2openscad

An Inkscape extension that converts 2D architectural SVG floor plans into fully parametric 3D OpenSCAD models.

Unlike general path-to-OpenSCAD converters, this extension is semantic. It reads your layer names (or individual object IDs/prefixes) in Inkscape, extracts the coordinates, and wraps them in custom procedural OpenSCAD modules representing architectural features.

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Features

• Semantic Prefix Identification: Automatically matches paths by their layer name or object ID prefix and maps them to specialized OpenSCAD modules.
• Parametric Controls: Custom dimensions (wall height, door clearance, window sill/header heights, slab thickness, balcony wall heights, and frame widths) are exposed as global variables at the top of the .scad file.
• Base Scale Conversions: Tweak the output base scale dropdown in Inkscape to match your drafting units (e.g. 1 unit = 3cm, 1cm, 1mm, or 1m).
• Hole and Subpath Support: Correctly renders nested paths (such as walls with inner cutouts or donut slabs) as OpenSCAD polygons with hole indexes.
• Comprehensive Transform Support: Parses paths, rectangles, circles, ellipses, lines, polylines, and polygons, automatically applying cumulative group transforms.
• On-Canvas Scale Calibration: A helper extension drops a resizable "1 m" reference bar into a corner of the canvas. Drag it to match a known real-world distance in your drawing, and the conversion automatically calibrates the whole floor plan's scale from the bar's resulting length — instead of relying on the fixed 96dpi assumption. The ruler itself is never rendered in the .scad output.
• Per-Category File Export: Optionally write one .scad file per semantic category ({NAME}_wall_outer.scad, {NAME}_door_wood.scad, etc.) instead of a single combined file, so each category can be imported separately into tools like FreeCAD that otherwise treat a .scad file's union() as one opaque object.

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Semantic Categories & Prefix Rules

Name your Inkscape layers (or individual object IDs) with one of the following prefixes (case-insensitive):

Prefix	Element Type	OpenSCAD Module	Description
floor_	Floor Slabs	floor_slab(points)	Slab extruded downwards below Z=0
wall_outer_	Exterior Walls	wall_outer(points)	Full-height exterior structural walls
wall_inner_	Interior Walls	wall_inner(points)	Full-height interior walls
wall_balcony_	Balcony Walls	wall_balcony(points)	Half-height masonry walls for balconies
door_wood_	Wooden Doors	door_wood(points)	Standard door (wood leaf + lintel above)
door_glass_	Glass Doors	door_glass(points)	Wood frame + translucent glass panel
sliding_door_	Sliding Doors	sliding_glass_door(points)	Minimal dark frames + large sliding glass panes
window_standard_	Standard Windows	window_standard(points)	Wall sill + frame + glass pane + lintel
wardrobe_	Built-in Closets	wardrobe(points)	Floor-to-ceiling closet block

Warning: If an object or layer does not match any known prefix, it falls back to a standard wall extrusion, and a warning is printed in the Inkscape interface.

This table, the Add Semantic Layer extension's dropdown, and the starter template below are all derived from the same CATEGORIES mapping in categories.py, and the latter two are checked in CI against that mapping — so there's nothing to keep in sync by hand beyond this table itself.

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Base Scale Configuration

The dropdown in the Inkscape extension interface adjusts the unit scale and parameters:

• 3 cm (Architectural 1:100 draft): 1 unit = 3cm. Ceiling height is 80.0 units.
• 1 cm: 1 unit = 1cm. Ceiling height is 240.0 units.
• 1 mm: 1 unit = 1mm. Ceiling height is 2400.0 units.
• 1 m: 1 unit = 1m. Ceiling height is 2.4 units.

Note: This dropdown only relabels the output unit and sets the ceiling/door/window Z-height constants above — it does not rescale your drawing's XY footprint. The real-world plan size comes from your SVG document's actual width/height/viewBox, or from the on-canvas scale ruler if one is present (see below).

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Scale Ruler & Calibration

Run Extensions → Floorplan → Add Scale Ruler to drop a bar (with end ticks and a "1 m"-style label) into a corner of the canvas, sized against your document's actual width/height/viewBox. Unlike the earlier one-shot guide, this bar is a live calibration control:

1. Select the ruler's bar (or drag a box around the whole ruler — bar, ticks, and label together) and resize it with Inkscape's selection tool to match a real-world distance you can see in your drawing (e.g. stretch/shrink it to line up against a wall you know is 4m long).
2. Run Semantic Floorplan to OpenSCAD as usual. The conversion looks for the ruler bar anywhere in the document (hidden or visible), measures its current length, and uses that to calibrate SCALE_FACTOR for the whole model — overriding the fixed 96dpi assumption the base scale preset would otherwise use.
3. The ruler itself is never written to the .scad output, regardless of whether it's visible or hidden.
4. If you don't add a ruler, conversion behaves exactly as before: real-world size comes from the document's width/height/viewBox.

If you resize the whole ruler (bar + ticks + label) proportionally, everything stays visually aligned. If you only stretch the bar itself, the ticks/label won't follow — that's fine, since only the bar's endpoints are used for calibration.

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Installation

1. Clone or download this repository.
2. Move the floorplan2openscad folder into your Inkscape extensions folder:
   • Linux: ~/.config/inkscape/extensions/
   • macOS: ~/Library/Application Support/org.inkscape.Inkscape/config/inkscape/extensions/
   • Windows: %APPDATA%\inkscape\extensions\
3. Restart Inkscape. The extension will appear under Extensions → Floorplan → Semantic Floorplan to OpenSCAD, alongside two helper extensions: Add Semantic Layer and Add Scale Ruler.

Installing the starter template (optional)

To start new floor plans with all nine category layers already created, copy templates/floorplan-starter.svg into Inkscape's templates directory:

• Linux: ~/.config/inkscape/templates/
• macOS: ~/Library/Application Support/org.inkscape.Inkscape/config/inkscape/templates/
• Windows: %APPDATA%\inkscape\templates\

Restart Inkscape; the template then appears under File → New From Template. Delete any layers you don't need before drawing.

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How to Use

1. Draw your floor plan elements in Inkscape.
2. Group or layer your shapes and label the layers using one of the prefixes above (e.g., a layer named wall_outer_ground). Instead of typing a prefix by hand, you can run Extensions → Floorplan → Add Semantic Layer, pick a category from the dropdown, and give it a name suffix — it creates the correctly-prefixed layer for you (as a top-level layer or a sublayer of the active layer). Starting from the starter template (see above) skips this step entirely for the common categories.
3. Not sure if your drawing is the right real-world size? Run Extensions → Floorplan → Add Scale Ruler to drop a resizable "1 m" (or 10cm/50cm/2m/5m) reference bar into a corner of the canvas. Drag it to match a known distance in your drawing — see Scale Ruler & Calibration above — and the conversion will use it to calibrate the model's scale. It's excluded from the .scad output either way.
4. Convert all shapes to paths: Path → Object to Path (Ctrl+Shift+C).
5. Run the extension: Go to Extensions → Floorplan → Semantic Floorplan to OpenSCAD.
6. Select your output .scad filename and base scale, then click Apply. Check Export a separate .scad file per category if you want one .scad file per semantic category (e.g. for importing walls, doors, and windows separately into FreeCAD or another CAD/BIM tool) instead of a single combined file.
7. Open the generated file in OpenSCAD to customize, preview, and export your 3D architectural model.

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License

This project is licensed under the MIT License - see the LICENSE file for details.