I've exported a 2D drawing from Sketchup which consist of not filled shapes made with lines. I want to keep the exact dimensions and manipulate it in Inkscape, so I imported it using Vector Magic. The problem is that it "translates" the lines as shapes themselves; i.e., it fills their thickness as if they were actual shapes:
Is there anything I can do in Inkscape (please don't mention other software) to have those lines as just mere lines/strokes without any fill or thickness?
What you want is 'Centerline Trace'. Inkscape provides a tutorial (though it's for Windows) on their site here:
https://inkscape.org/en/~arpruss/%E2%98%85centerline-trace-on-windows-instructions
There's also a repo on Github here:
https://github.com/fablabnbg/inkscape-centerline-trace
Centreline trace pretty much does what the name says. It'll create a line from tracing along the middle of a filled object. It should do exactly what you need.
The inkscape-centerline-trace plugin depends on autotrace, which is known to have major security vulnerabilities. While windows binaries are still available, other systems have removed autotrace entirely and recommend against compiling it.
Sadly, for now the best option for centerline vectorization seems to require using services outside of inkscape (e.g. the free but proprietary http://online.rapidresizer.com/tracer.php)
