I'm fairly new to CAD/OCCT, working on an importer using XSControl_Reader. For some igs/stp files, I get a report that there is a number of "unknown entities" when reading the file. The documentation is clear that unknown entities do not constitute an error or erroneous entities. So I'm wondering what exactly these unknown entities are and if I need to care about them. After doing a transfer of the root entities for one such file (which reported 9 unknown entities), PrintStatsTransfer(4) shows:
Count Check ** TRANSFER READ CHECK **
10 W:ADVANCED_FACE: Unknown message invoked with the keyword FixAdvFace.FixMissingSeam.MSG0
So my initial guess would be that the "unknown entities" the file had were "ADVANCED_FACE" entities that had to be fixed for missing seams during the transfer process? If so, I guess the transfer was effectively ok and I can go ahead and use the results without issue. Is that vaguely correct? Is it generally safe to ignore warnings about "unknown entities" during the read process?