Importing and exporting drawings
DXF and LandXML in and out, and what a format can honestly carry.
4 min read
What travels
| Format | In | Out | Carries |
|---|---|---|---|
| DXF | yes | yes | Layers, lines, polylines with true arc segments, circles, points, text, blocks as geometry |
| LandXML | yes | yes | Surfaces, alignments, points |
| CSV / TXT | yes | yes | Points, with your column order |
| no | yes | Plotted sheets, locate reports, cut sheets |
Importing a DXF
- Curves come in as curves. An arc segment on a polyline, a curb return, a radius corner, a cul-de-sac bulb, is read as the true circular arc, to within a centimetre of the geometry, never flattened to a straight chord. Old-style POLYLINE entities import the same way.
- Anything the importer does not carry is counted and named, blocks arrive as the geometry they draw, and nothing is dropped silently.
- A DXF written by design software often saves sheet furniture (title block, legend, north arrow) near the drawing origin alongside the real linework at survey coordinates. Backsight notices the two clusters, tells you which layers sit in each, and offers to re-import with the near-origin content left out, dropped entities are itemised, never quietly gone.
- Deleting an import (Import / Export panel) removes what it brought, its entities, its now-empty layers and the stored file, and leaves your own drawn work alone. Re-importing is always clean.
Exporting
- Import (top bar, any mode) → DXF or LandXML drawing, which opens the Import / Export panel in the drawing's dock on the Draw tab.
- Choose the format and what to include.
- Export. The file is written and kept with the project.
Refused rather than silently dropped
If a format cannot carry something, Backsight names it instead of writing a file that quietly lost it. Blocks export as the geometry they draw, which every CAD opens correctly.
About DWG
Backsight does not read or write DWG. It is a proprietary format, and a reverse-engineered reader that opens most files and mangles the rest is worse than an honest DXF. Every CAD package on the market reads DXF.
Read next
- Drawing: tools, the command line and snapsHow to draw, how to be quick about it, and how to make things land exactly where you mean.
- Sheets: setting one up and plotting itA sheet at a real scale, with a title block, a legend and your logo: then a PDF you can prove.
- File formats Backsight reads and writesWhat you can bring in, what you can take out, and what each format carries.
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