Hi All,
When I export a simple singular arc as a .dwg, I can import it into ACAD and it will remain as an arc.
If I draw a straight line to close the arc and join the arc and the line together, it will change to a spline…
If you do the exact same steps, but draw the arc in ACAD instead of importing it. The resulting joined geometry will be a polyline.
How do I stop the imported arcs from changing into splines after joining?
Hi @thomas_simmons,
There are dozens of options that are stored in the AutoCAD export schemes that control how the exported geometry is translated to the DWG format.
You can modify the schemes and create customs one too.
Try the CAM Imperial or CAM Metric flavors AutoCAD Export schemes.
Use this scheme keep lines as lines and arcs as arcs.
Select to explode or keep joined.
The DWG file I exported, imported to AutoCAD as a line and arc with the explode polyline checked. With it unchecked, it imported as a polyline that could be exploded in AutoCAD.
Let us know if this works for you.
If not please post a file and let us know which AutoCAD export scheme that you are using.
Thanks,
Mary Ann Fugier
Thanks Mary,
I’ve been doing some testing since and have found a solution. There are a few scenarios in which the results are different and require extra steps.
Scenario 1:
Arc has been drawn in the xy plane in Rhino.
When exporting, chose 2007 natural scheme and tick the “flip arc normals to +Z” box.
This will import as an arc, and when joined to any other lines will become a polyline instead of a 3d polyline. Which is preffered in my case.
Scenario 2:
Arc has been drawn in 3d (not on any plane). If you follow the above steps, the resulting joined geometry will become a 3d polyline.
The work around is to create a block in which its xy axis is oriented to the plane of the arc.
Export the block with the same scheme as per scenario 1. Once imported you can explode the block and the resulting joined geometry should be a polyline.
