Broken & uneven autocad lines



I am working on a project which has lots of curves & lines which seems perfect in autocad, but when i import the same the position of curves are different & i am not able to work with those lines to make faces. It is like re drafting all the curves in sketchup.

Please help!


Might you share the CAD file so we can see the problem firsthand?


01 Interpretation Centre.dwg (407.9 KB)

Here is the autocad file. Please have a look to it and help me in this problem\




There are no true circles, arcs or curves in SketchUp
SketchUp portrays circles, arcs and curve entities as a series of contiguous straight line segments.

Measuring from center of a circle or arc to the vertices of the line segments yields the true radius.
However, measuring from center to anywhere else along the line segments is less than the true radius.
Thus, the lines depicting stair treads extend beyond the segmented SketchUp arc.

Make a copy of the DWG and open it in AutoCAD.
There, explode the arcs, save, close and then try importing into SketchUp.

I didn’t bother with exploding certain arcs, I simply exploded everything.
The resulting SKP file is huge (140MB) but it looks as you would like it to look.

See this article for more tips.
Importing and Exporting CAD Files — SketchUp Help


But, practically the file will be heavy eventually and laggy to work with.


True, but there are ways to manage the beast.

• Back in AutoCAD, export logical sections of the drawing to create a set of DWG files.
• Upon import into SU, each of those DWGs comes in as a Component.

• Assign each Component to a new Layer.
• Turn on the Layer(s) you want to work with and leave the others off.

This method won’t reduce the file size, but it will certainly yield better performance.
You’ll find many more performance modeling tips here…


I’m not sure I entirely understand the question. Are you looking to just make faces or do you need cleaner curves with less segments? - as SketchUp converts CAD arcs to a series of straight lines.

There are some extensions that can help you make faces if that’s the priority here. You can try Edge Tools though on this particular file it didn’t seem to help. Try Extend Close Lines, it’s a paid plugin but may be worth it if you work with CAD files often. See below for extending small gaps that occur when SU segments the CAD arcs.

Then, run MakeFaces or similar extension to create faces.

Also, make sure to group or block any objects or linework (like that arrow) that you don’t want intersecting with your lines so you can work with them separately as needed. Good luck.


I think the primary problem is presented in the OP’s title: Broken & uneven autocad lines

In AC, the lines depicting the steps meet perfectly with the arc depicting a curved stringer.
But in SU’s coarsely segmented interpretation of the arc, the lines depicting the steps run across the arc.

The lines depicting the steps are correct length in SU and need to remain so.
Thus erasing the bits that run through the arc isn’t an option.

From here, making faces appears to be a secondary issue.
Despite improvements in SU’s native ability to create faces when lonely edges project inside the loop, they can still cause problems.

I find MakeFaces v.1.400 by Todd Burch often succeeds when tracing an edge of the loop fails.