SU DWG/DXF export duplicates (multiply) all the edges

  1. When I export dwg or dxf as 3d choosing only edges in export options dialogue and then try to import this dwg or dxf file into rhino or 3ds max in order all circles could be as real circles (without segmentation) I see that there are a lot of duplicated lines, circles. Here is a simple example of a cylinder created in SU and then imported to 3ds max. See that there are these duplicated lines, circles.

Why is this happening? 2. And by the way as far as I remember it’s not impossible to export it from SU in a way that not only edges were represented in other CAD applications but surfaces (faces) also? Because when in dwg export dialogue I choose edges and faces it exports faces for example of a cylinder as segmented polygons together with edges thar are really curves but not the faces.

That is because SketchUp is a face modeller. It doesn’t support curve-based surfaces. SketchUp faces appear as polyfaces in AutoCad.

ok, and does that also means that someone who will get from me dwg file where only edges were included it will take a lot of time for him trying to recreate all the surfaces of my model because of he’ll get only edges or maybe there are some automatic functions for example in AutoCAD that will help him to do it automatically instead of manually recreacting surfaces for all the parts having only edges? And I also don’t understand why all the edges becomes duplicated many time as I described here in the 1st question.

If the point of sending them a DWG file is to recreate a 3D model with surfaces in a different tool, maybe a different format would be better. Perhaps give it the original SketchUp file, that’s in the list of import formats for Rhino.

If it’s for CNC, the edges represents cuts, and it doesn’t matter whether the part to the left of an edge is going to be used or discarded, the face information isn’t needed.

I don’t know Rhino (and don’t have $995 worth of curiosity), but would their FillMeshHole command help?

Rhino is able to import .skp but all the circles for example becomes segmented. But most of all now I’m interested in why dwg format duplicates all the edges multiple time?

I’m not Rhino user but I’ve downloaded a trial version of it to check what kind of data it imports and how skp file looks in it. I’ll try this command to see the result

Note that Rhino doesn’t support the SketchUp 2020 format, you must save your model to an older version, 2017 would be safe, I think.

yes, I know it. The same thing for some other software that don’t support actual skp versions

@colin so could you comment why does it export with edges duplicated? You can also check it when export 3d dwg file (with 3d object, not 2d flat polygon) and open it for example in Adobe Illustrator where you’ll see in the layer stack that edges have been duplicated multiple times.

You should only see two sets of edges if you had Faces turned on when exporting.

This is a simple cylinder exported as dwg with edges and faces turned on in the options dialogue. So after I open it in Illustrator you can see that there are still a lot of duplicated contours. Look files attached.

test.dwg (38.2 КБ) test.skp (77.9 КБ)

That looks correct. You normally would turn faces off.