Hi,

This is great news, the samples are looking great!

The rendering and vector curves overlapped is something I have never seen and will be a major timesaver for my work.

When profile lines have less segments (joined curves) it's easier to edit afterward.
I imagine it must be hard to set a mechanism that works great in all situations though.

I use hidden lines from time to time in illustrations or schematics.

As mentioned, a closed shape for the main silouhette would be great.
An option for different colored lines could be enough to edit the thickness of lines in 2d vector editors (for example oulines, details and hidden.)

It might be interesting to have a special export window, like when exporting polygons.
It could have a preview and some options for including the rendering or not, lighting options, hidden lines, resolution, etc.

Or maybe a 'options' button in the export pdf file dialog window could be handy.

Marc