finding parting lines for mold making in MoI

 From:  Frenchy Pilou (PILOU)
10212.2 In reply to 10212.1 
Seems any curves (or surface, or volumes) can make that ... just boolean diff...on any volumes...
with keeping or not volumes depending of what is wanted...
here curves

EDITED: 6 Mar 2021 by PILOU