Inaccurate import DWG/DXF into SU

Hi all,

I have drawn shapes (gothic windows) with various curves in Indesign, then imported them into Illustrator, and from there exported them as a cad-file. When imported to Sketchup, all kind of small details are slightly off (see pictures). I have checked all nodes and curves in Illustrator, and they perfect - the problem seems to arise when importing in SU. I am working on a Mac.

I have tried varying between DWG and DXF, and also between different versions of Autocad, but inaccuracies remain. It’s annoying, because the details are important - repairing them is a lot of work, and not as precise as the original.

Does anyone know if there is a solution?

Below a screenshot of a detail in the CAD file (in Illustrator), and the same detail as it turns out in SU - the errors are in the corners.

In my experience, sketch up kind of destroys .dwg files, especially curves because sketch up doesn’t make actual curves, it makes a series of small lines. You may want to check out Thom thoms ruby scripts, he has some great ones for importing cad files and cleaning them up.

Hi Larry,

Thanks for your answer. I noticed that SU takes a rather straight approach to curves, but in combination with the smoothing tool, the curves themselves look fairly good I think. The problem apparently is in the connections - and not only with curves, even very straightforward 90* angles get strangely deformed when imported! (see pic below for difference between cad file en SU).

Thanks for mentioning the scripts by ThomThom - however, I have not been able to find them. I found numerous plugins by him, but none that seem to deal with importing dwg. Or am i missing some script-archive? Could you perhaps point out to me where I can find the scripts?


It looks like a size issue - what are the dimensions of the geometry?

SketchUp can only handle edges down to about 0.001" in length.

Hi Jim, thanks for the suggestion. However, the detaill with the two distorted rectangles is more that 1 meter wide, so I doubt size would be the reason. It is true that in Indesign the drawing is much smaller, but when exporting from Illustrator to DWG I enlarge the scale to life size. This is then imported into SU.

Hi Manonschuitema,

No conversion is lossless. Scaling during export only adds another variable to the mix.
Why not simply model these in SU instead of all the conversions?


Like I said it destroys .dwg files. The scripts are not for importing dwg files better. They need to be fixed basically. Here is one thom thom ruby, its called “edge tools” [Plugin] Edge Tools • sketchUcation • 1
another one would be “cleanup” [Plugin] CleanUp • sketchUcation • 1
Just some suggestions. I agree with Geo’s comment

"Hi Manonschuitema,

No conversion is lossless. Scaling during export only adds another variable to the mix.
Why not simply model these in SU instead of all the conversions?"

Thanks Geo and Larry for your answers and pointing me to the scripts. Regarding modelling directly in SU, I agree this would eliminate the problem with the import - but I’m working with elaborate material (based on old medieval etchings) that already has been drawn in Indesign. I tried if not scaling would improve matters, but the errors remained (just 100 times smaller :wink:

But I found the reason and the solution for the problem: the paths in the dwg file were connected. Apparently SU has difficulties tracing them in that way. When I cut loose every curve and straight line in Illustrator first (fairly easy to do), the DWG then imports perfectly into SU. You can even add a few more anchor points to the curves in Illustrator too improve the result after smoothing in SU (I know you have to limit that though because of files-size).

Thanks again!

You have yourself discovered the best available tricks. The problem with InDesign/Illustrator geometry is that everything tends to consist of Bezier curves that are nonexistent in SketchUp, and the importer is not too perfect at approximating them. That is why doing the straightening in Illustrator and adding an appropriate number of nodes helps to make the result more consistent.


I’m running into the same problem you are are and happened to stumble across this thread. I see you found a solution but I don’t know what you mean by “cut loose every curve and straight line”. Can you please explain?

Hi Stephan,

SU has difficulties importing combinations of connected lines.

See the screenshot below of a church window in illustrator. Fill is black, outline is none.

At the left, all paths are connected, and therefore shown as filled. At the right, all individual parts of the paths are cut loose. You do this by selecting the scissor-tool in Illustrator, and clicking on each node between different parts of a path. In a bezier-curve, this means doing that with every node in each curve. The only exceptions are the full circles, as SU has no problems importing those. All in all a pretty laborious task, but it allows for perfect import in SU.

When exporting to DWG from Illustrator it makes no difference if you turn on fill and outline or not, I just assigned those here to show the difference between left and right. Also, It helps keeping track of your work when cutting loose the sides.

To all full circles, I added nodes in illustrator in order to improve the number of sides after importing them in SU, but this is not strictly necessary.

Hope this helps!

Thanks for the discovery, it helped me a lot.

I want to add that it would be simpler to edit the dwg file after export, select all entities and explode them.