DWG, DXF, PDF, image: the differences
| Format | Nature | Units and scale | Layers | Good for 3D? |
|---|---|---|---|---|
| DWG | Native CAD file, binary | Yes, in the file | Yes | Yes, the best starting point |
| DXF | CAD exchange file, text | Yes, in the file | Yes | Yes, equivalent to DWG for a floor plan |
| Vector PDF | Page with lines and texts | No: scale to calibrate | No | Usable with calibration and manual tracing |
| Scan, JPG, PNG | Pixels | No: scale to calibrate | No | Usable with more work and less precision |
ShotPlan reads DWG and DXF Available; PDF and image recognition is Coming soon.
How to get the DWG or DXF of a floor plan
- From the designer. The studio that drew the project has the DWG. Ask for the floor plan of the storey you need, with the layers switched on.
- From your own CAD. Every CAD program saves as DWG or exports to DXF (“Save as” or “Export”). Prefer a recent version of the format, but not necessarily the latest.
- From a PDF. Some programs convert vector PDFs to DXF: the result keeps the lines but loses units and layer names. It is a fallback, not the ideal path.
- From a survey. A new survey, even a simple one with a laser meter, drawn in a CAD, is often the fastest way to get a reliable file for an old building.
What to check before importing
- Units. Is the drawing in millimetres, centimetres or metres? The file header says so; if it is missing, you will calibrate with a known measurement.
- Scale 1:1. In a CAD the drawing should be in real units: a 5 m wall is 5000 mm long. If the file was drawn “to paper scale”, calibrate.
- Layers. Walls, openings, furniture and dimensions on separate layers make tracing easier: you can hide what does not help.
- Closed lines. Walls drawn as double lines that meet at the corners make snapping and room generation reliable.
- One storey per file. If the file contains several storeys or an elevation, isolate the floor plan you need.
From the file to the 3D
Once the file is clean, the path is the one in the 2D to 3D guide: check the scale, trace the walls on the lines with snapping, place the openings, generate the rooms. In ShotPlan the layers of the DWG stay available in a panel, so you can show only the walls while you trace.