Hi Paul, it looks like this will work. I've added a new "isTemporary" property for construction lines. By default it is true but if you set it to false then it won't get erased at the end of the current command.

So this enables setting up a keyboard shortcut like K to keep construction lines with this as the command:

script:moi.geometryDatabase.getObjects().getConstructionLines().setProperty( "isTemporary", false );

And then maybe something like Ctrl+K for removing them by doing this:

script:var gd = moi.geometryDatabase; gd.removeObjects( gd.getObjects().getConstructionLines() );

They will persist until you erase them or something erases the entire geometry database (like File / New or Open). But they won't save to a .3dm file right now, that will have to wait for a later version.

For this to work you will need an updated moi_lib.dll, I have a couple of other things I want to try before posting a new patch, I think it might be a day or two before I am ready to post it.

- Michael