True Arcs and Circle geometries - not just a series of straight lines

We use sketchup to create drawings for film sets. More and more items are exported for CNC and laser cutting. Items with curves we have rebuild in Autodesk Autocad to send true curve geometry to the laser cutting and CNC companies. If sketchup had True Arcs and Circle geometries it would be almost complete CAD software.

Export your circles and arcs using the 3d option to .dxf and they will be true circles and arcs.


When I export my 2d flat model using 3d export I still get short line segments. Not true circles.

Is there another way?

If you export as 3D dwg or dxf and get segments instead of true circles or arcs, it is a sign that you have edited the model in a way that caused SketchUp to forget that the segments represent a circle or arc. You can tell this has happened if you select a segment and get just it, not the entire circle or arc. Sometimes you can weld (using an extension) the segments back together and SU will recover the circle metadata, but not always.

That’s not an attack on your modeling skills, and it does not mean you overlooked some warning. It is just something that SketchUp does when it concludes that the circle definition is no longer valid.

thank you for the response. Can I redraw the circle?

I have employed the weld extension and redrawn the circles and arcs multiple times. I have reset the 3d settings to edges only. Truview still says the " circles " are not circles. This is important because the cam software used on most pattern cutters will start OFF the line toward the center of a circle using a lead-in - lead-out to cut a near perfect hole and the tool offset is to the inside of the hole. For a series of lines the start point is on the end of one line and the tool offset is unknown at times.

The only way to correct this is to redraw the circles in cam software. This operation makes the nesting file nonnative to the cad software allowing for errors and additional cost for every change. I make mostly custom equipment with may adaptations so efficient processing is needed. Export to DXF producing true circle definition is critical to the cost of production in my operation. Please assist me to find a way to make this work. Thank you.

how do I attach skp.

This is a screen shot of the truview readout.

See the post above, I thought it wasn’t possible to get true arcs but you can. My workflow is different to yours but the principle is the same.


File>Export>3d Model (not 2d graphic)
Change filetype to DXF

Have a read and see what you think

Hope it helps

7th button from the left, I could try it see what happens