Draft OCA

From FreeCAD Documentation


Draft OCA is a software module used by the Std Open, Std Import and Std Export commands to handle the OCA file format.

The OCA file format is a community effort to create a free, simple and open CAD file format. OCA is largely based on the GCAD file format generated from gCAD3D. Both formats can be imported in FreeCAD, and the OCA files exported by FreeCAD can be opened in gCAD3D.


The following OCA objects can be imported:

  • Lines
  • Arcs and Circles
  • Closed areas


The following FreeCAD objects can be exported:

  • Lines and wires (polylines)
  • Arcs and circles
  • Faces


See Import Export Preferences.


See also: Autogenerated API documentation and FreeCAD Scripting Basics.

To export objects to OCA use the export method of the importOCA module.

importOCA.export(exportList, filename)
  • For the Windows OS: use a / (forward slash) as the path separator in filename.


import FreeCAD as App
import Draft
import importOCA

doc = App.newDocument()

polygon1 = Draft.make_polygon(3, radius=500)
polygon2 = Draft.make_polygon(5, radius=1500)


objects = [polygon1, polygon2]
importOCA.export(objects, "/home/user/Pictures/myfile.oca")