SUMMARY No thumbnail for FreeCAD files. STEPS TO REPRODUCE Simply open Dolphin and look for a folder containing a FreeCAD file (*.FCStd) OBSERVED RESULT No thumbnail ! EXPECTED RESULT Display thumbnails. Each .FCStd is an archive containing several files, including a PNG file for thumbnail. Here, the path : my3Dfile.FCStd/thumbnails/Thumbnail.png SOFTWARE/OS VERSIONS Linux/KDE Plasma: Debian 12 KDE Plasma Version: 6.3.4 KDE Frameworks Version: 6.13 Qt Version: 6.8.2
KDE now supports the 3rd party thumbnail spec. See (https://tecnocode.co.uk/2013/10/21/writing-a-gnome-thumbnailer/) . There might be one already. KDE having it's own one would would not scale well.
So what? I have to use gnome-thumbnailer? ...I'm not sure I understood your answer...