Workflow Autocad/Rhino to Sketchup - Arcs & lines

Hello everyone!

I am trying to come up with a workflow between Autocad en SketchUp:

I have a bunch of polylines formed with lines and arcs in cad format, like below:

I have tried 2 workflows:

  1. Import the cad file from sketchup
  2. Import the cad file into rhino and export it to sketchup

1 If I just import the cad straight away the arcs get converted to lines. In some cases it is just a line, in some others there are 2 lines or even 3. I guess it depdends on how long the curve (arc) is

2 If I use rhino it is even worse. The lines in rhino appear to be like splines in autocad, please see screenshot below:

I export that rhino file to sketchup and I open it in sketchup. I get this, curves simplipfied to straight lines:

I checked the guidance and sketch up should not be doing this

Would this be an issue of scale maybe? I am doing my test but I would thank some help!

Thanks everyone!


Can you share the dwg file?

Add more points on splines/curves,arcs.

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Hi @francisquitof

Sure! I can send a portion of the file where the problems happen. Please find attached

Polylines lines and arcs_2010.dwg (87.0 KB)
Polylines lines and arcs_2018.dwg (41.2 KB)

I have saved in dwg version 2010 and 2018

Let me know if this is ok!


Hi @mihai.s

Thanks for you help, I looked through your post but now it has been deleted


After you added the dwg files, I tested them and saw that you can get those smooth curves directly in SketchUp.
But you can also use the spline editing method in acad, by adding points.

Hi @mihai.s

Really? how did you do it? could you please guide me briefly through the export/import process and its settings?


A few methods


What methods have you used there?

As far as I see, you only have used Curvizard,

By other hand and regarding your latest post, the curves from autocad do not appear in Sketchup exactly as they were. SketchUp simplifies a lot and does not keep the navite data


I just imported the file you posted in the forum.

The first method, I drew an arc. Second, I used Fredo Curvizard. Third, first I welded the three edges, and then with Curic Edge2Arc I transformed curve into arc and changed the number of segments from 3 to 12.

In AutoCad, another option is to convert the splines into standard polylines (arcs and line segments) with the Splinedit command.

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Hello everyone,

Thanks for you help, nothing really works for now, the data is lost or changed. I cannot get exact area number from cad to sketchup and viceversa

If you come up with a sensible solution please let me know but my feeling is that sketchup is not able to handle this kind of entities properly



it’s always hard to import arcs / polylines from autocad without losing precision, at least since sketchup 2016 (if I remember well)

Here’s the workflow :

  • in autocad, first select all and enter the command EXPLODE (in your file, your polylines are joined arcs, lines etc.)

  • type SPL (for SPLINE) and O (for OBJECT) and select all, validate.

  • type PE (for PEDIT) and then M (for Multiple as prompted in the cmd line) and select all, it’s going to ask you if you want to convert elements to polylines. type Y (YES) and it’s going to ask you for a precision that has to be set between 0-99. The higher the precision, the more segment you’ll end up with. don’t go too high as it would be too heavy once in sketchup.

Tada ! you can now save your dwg and import it in sketchup.

Here it is with a 50 precision (which is already too high to my mind - 101017 edges), but at least it is smooth. Work with this precision parameter to find the right compromise

Polylines lines and arcs_2010 precision 50.dwg (1.3 MB)

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Hello @paul.millet

I get stuck on the SPL command

I get this:

Before I select the files it shows:

‘SPLINE Select spline-fit polyline’ but after exploding there is no splines


@sjaviergmanso I’m sorry I recently moved from AutoCad to BricsCad and I thought it would act the same way, as it usually does. apparently not.

Do you have autocad or autocad LT ?

Hello @paul.millet

I am using Autocad 2024 the full version


you’ll then be able to use LISP commands (that are not available on LT version) to convert those arcs to segments.

follow this :

I don’t have much time right now to try it out and I’d have to do so on another computer that has autocad installed. But if you have troubles using it I’ll help you later on - or help you find another Lisp that would suit.