Rhino (.3dm) Import/Export

Opening Rhino files

The current version of Rhino will open files from any previous Rhino version and Rhino backup files (.3dm.bak and .3dmbak).

  • Dimensions created with History in Rhino 5 do not update in Rhino 8, but their history data will be retained.

  • When Rhino 8 opens the 3dm files saved by Rhino 4 or some early versions of Rhino 5, Layout space scaling is disabled.

  • When a command's history data is significantly changed in a newer Rhino version, (e.g., 8.1), the History record will not replay in 8.0 and any older versions.

  • Auto save is disabled when opening an old version 3DM until it is saved as the current version format.

    The MacDisplayOldVersionAutosaveWarning setting in Rhino Settings > Advanced controls whether the warning will display.

Missing font detection

Rhino detects if any of the fonts used in annotation styles or objects are missing on the system when opening 3dm files. If missing fonts are detected, a warning dialog appears, and the details are listed in the command history. Missing fonts will display with a substitute font. The substitute font does not replace the missing fonts unless you change them.

Don't show this message again

Enable this checkbox to stop showing the warning dialog.

Set Rhino.Warnings.MissingFontWarning=True in Advanced settings to show the warning dialog again.

Saving Rhino files

The current version of Rhino will save to any previous Rhino version files except V1.x.

To save a model as an earlier Rhino file:

  1. From the File menu, click Export Selected or Save As.
  2. In the dialog box, in the Save as type box, select the Rhino version.
  3. In the File name box, type a file name.
  • The UseCompressionWhenSaving setting in Rhino Settings > Advanced decides whether mesh data will be compressed in 3dm files. It is turned on by default. Turn it off to reduce 3dm saving time with a larger file size.

Saving as Rhino 7

When saving to Rhino 7 files, new data in Rhino 8 files will be lost. Details...

Saving as Rhino 6

When saving to Rhino 6 files, the following changes take place:

  • SubD texture coordinates will be lost.
  • Physically-based rendering materials will be read as placeholders in the Materials panel.
  • New TextFields in v7 will not be resolved in viewports.

Saving as Rhino 5

When saving to Rhino 5 files, the following changes take place:

  • Annotation styles and objects lose enhanced V6 information.
  • Annotation objects should look as close as possible between V5 and V6.
  • When saving annotations from V6 to V5, please make sure important information is not lost.
  • SubD objects are saved as ordinary mesh objects.
  • V6 material types will be converted to V5 Basic Material type.

Saving as Rhino 4

When saving to Rhino 4 files, the following changes take place:

  • Extrusion objects are saved as polysurfaces (but not lost).
  • Some of the annotation objects lose enhanced V5 information.
  • Minor things like display order, Gumball user data, and so on.

Saving as Rhino 3

When saving as Rhino 3, the following changes take place:

  • Layers, materials, and object attributes are saved in simpler V3 formats.

The following data is not saved:

  • History information.
  • Advanced texture mapping information.
  • Custom display information.
  • User data.

Saving as Rhino 2

When saving as Rhino 2, the following changes take place:

  • Objects that contain non-NURBS geometry (spheres, cylinders, arcs, circles, etc.) are converted into NURBS objects. Sometimes this results in some less precise trimming curves. In particular, some geometry does not round trip to Rhino 2 and back.
  • Layers, materials, and object attributes are saved in simpler V2 formats.
  • Point clouds are exploded into single points.
  • Blocks are exploded into their component geometry.
  • The following data is not saved:
  • Annotation.
  • Render meshes and analysis meshes.
  • History information
  • Advanced texture mapping information.
  • Custom display information.
  • User data.