do 3d face section

[feffe]

Good morning, I'm working with road reliefs I'm supposed to count on. to me come the 3d level curved reliefs, the 3d face model is some sections probably derived from the model.
I would like to try to make new sections but I can't with the commands at my disposal, I have autocad 2019. Thank you for giving me some advice

 

[Tristan]

if you have only autocad, you can extrude along a vertical direction the 3dfaces for a very small value, then sections the resulting solids with the Pianosez command

 

[feffe]

Is there a free program that does these sections? because the drawings represent stretches of 1-2km road with its adjacent hilly terrain... extending faces would become a little uncomfortable

 

[Tristan]

(AutoSEZ 2) Sezioni e Profili del Terreno - Estrazione automatica

La versione 2 di AutoSEZ. Per le modifiche e le nuove funzionalità vedere la sezione "Novità" nell'help (file AutoSEZ_2.CHM allegato), parecchie sono state dettate da richieste e suggerimenti formulati nel vecchio thread. Visto che il codice è stato quasi completamente riscritto, invito...

www.cad3d.it

 

[Tristus]

the method suggested by sadan It's the easiest to do with autocad.
3d faces can be extruded by selecting them all in one shot, but first it is good to transform them into surfaces, otherwise they create problems during extrusion (autocad muds).
at this point autocad will see both surfaces and 3d faces. with the command select similar it is necessary to delete 3d faces (those that create confusion to autocad).
After that, always selecting in one shot all the surfaces so created they can be extruded with the trajectory option to form a series of solids (a solid for each face).
with the union command you create a single solid and you can dissect it as you want.
There is no need to do it face to face.