Hi Nick, yeah that's possible to export 3D curves to SketchUp, they do get converted into line segments since SketchUp doesn't have actual smooth curves but they will remain 3D.

To do this to edges of a solid you will first need to create regular curves from the edges, then you can export the curves.

To duplicate edges select them and then do Ctrl+C to copy them to the clipboard, and then Ctrl+V to paste them back in again.

To select all edges on a solid, first select just 1 edge and then do Ctrl+A to then select all edges of that solid, or you can use the Scene browser to select all edges in everything by clicking on the "Edges" text in the Types section of the scene browser.

So anyway, after selecting edges and then doing Ctrl+C / Ctrl + V you will now have all the edges duplicated as curve objects and they will be selected. Now you do a File > Export to export the selected objects to SKP format and that will get you that wireframe outline into SketchUp.

Then since you have a bunch of extra curves you may want to delete them or do undo to remove them.

One note about SKP export - curves are only exported if they are the only thing that is being written into the SKP file. If you have some mixture of solids and curves, only the solids will be written. This is because it's pretty common to have some of the original construction curves in the model and when you do a SaveAs into SKP format I didn't want to have those curve kind of doubled up as additional edges written to the SKP file on top of the solid. So if you want to export curves you need to select only curves and do a File > Export.

Please let me know if you still have any problems,

- Michael