Import a floor plan and set its scale

Bring in a DWG, DXF, PDF, or image as your background, then set an accurate scale by ratio or by clicking two known points.

6 steps · 4 min read

An accurate background is the foundation of a trustworthy layout: if the scale is wrong, every light-level, spacing, and uniformity number downstream is wrong too. Spend the extra minute to calibrate, then sanity-check it with the measure tool before you place a single fixture.

  1. Import the plan

    Open the Plan menu and choose Import Plan. OpenLumen accepts vector CAD files (DWG, DXF), PDF drawings, and raster images (PNG, JPG, WebP). Vector and PDF imports keep crisp linework; image imports come in at 50% opacity so you can still see your fixtures on top.

  2. Pick a page from a multi-page PDF

    If your PDF has more than one page, the page picker appears with a thumbnail of every page. Click the sheet you want (usually the site or floor plan, not the title sheet) and OpenLumen rasterizes just that page into the canvas.

  3. Set the scale by ratio (PDF)

    For PDF plans you can set scale directly from the drawing's stated scale. Open Plan ▸ Set scale by ratio and pick an architectural preset (e.g. 1/8" = 1'-0"), an engineering preset (e.g. 1" = 20'), or a metric preset — or type a custom paper-to-real ratio. This works because the PDF carries its own resolution, so no clicking is required.

  4. Or calibrate by two points

    For any plan — including DWG/DXF and images — use Plan ▸ Calibrate (it reads Edit scale (two points) once a scale already exists). Click two points a known distance apart, then type that real-world distance. Enter it in your active units — feet when you're in Imperial, meters in Metric. A parking-stall stripe (about 9 ft / 2.7 m) or a standard door (about 3 ft / 0.9 m) makes a reliable reference. You can re-calibrate at any time if the first attempt was off.

  5. Read the current-scale readout

    Once a scale is set, the current scale is shown in the status bar (for example 1/8" = 1'-0" with the pixels-per-foot it works out to). Uncalibrated raster imports read "Not to scale" until you calibrate them. If your entered distance implies an impossibly large sheet, OpenLumen warns you (e.g. *"that implies the sheet is over 5,000 ft across"*) so you can double-check the number.

  6. Working with DWG and large files

    OpenLumen converts DWG files to DXF automatically, but very new AutoCAD versions aren't supported by the converter. If you see a "newer DWG detected" message, re-save the drawing as an AutoCAD 2010 DXF (or 2010 DWG) and import again. To keep things fast, trim unused layers and detail before exporting — a lean DXF imports and recalculates far quicker than a full construction set.