Here are *.vlx files of my version... Still for some complex roofs you have to manually find solution and only then apply solution to 3DSOLID converter...
If someone is interested for lisp code though, you can make a small purchase - contact me at : ribarm@gmail.com
Still I am not sure that purchasing will work as I only have credit card viable for my country - Belgrade, Serbia, Europe...
We'll see, but here are *.vlx which are doing the same thing, only you can't modify them...
Regards, M.R.
[EDIT : I've changed a little main *.vlx (found some lacks)...]
[EDIT : I've changed my mind - who downloaded, its downloaded, now I am removing attachments... Only if I have response on my mail and concrete offer - maybe applications exchange or something else - I may post my lisps to him/her... Thanks for understanding...]
[EDIT : I thought ab this and I decided that I still want to be generous, so I'll attach again my *.vlx files... Since last time there have been changing in coding so this version is 3-4 times faster and it gives better results... Still it is slow in comparison to chlh_jd's code, but my version won't fail no matter how reference closed polygonal polyline looks like... Further more I did everything I could with current (vla-offset), so final return of execution of routine will always be with as much as possible lines that are relevant for solution (or solutions if there are more like roof-ultimate-test.dwg), so you always need to remove sufficient lines and leave only those that make solution you want... Afterwards when drawing is finished - solution, you can apply roof-mr-3dlines23dsolid.vlx converter in order to make 3d solid - of course for this CAD has to have implemented SURFSCULPT command... - there have also been slight change in this routine too - it's now little slower in converting, but it's better as far as my testings prove...]
[Previously attached files :
roof-mr-3dlines23dsolid.vlx
roof-mr-3dlines-convex+concave.vlx]
[*.vlx files removed for commercial reasons...]