loop orientation flags do not match geometry

2010-06-02
2013-04-22
  • Running facetize I get this error:
    nmg_ck_lu_orientation() loop orientation flags do not match geometry

    What does this mean and how do I fix it?

    Gilligan

     
  • Sean Morrison
    Sean Morrison
    2010-06-02

    It means that something unexpected was encountered during the facetization process.  That failure can be completely benign and ignored, or it could indicate a modeling error (e.g., infinitely thin adjacent faces), or it could be a simple bug.  It's hard to say without seeing the geometry in question.

    If you feel it's a bug, please do file a bug report at  https://sourceforge.net/tracker/?func=add&group_id=105292&atid=640802

     
  • It can't be completely  benign, as facetize never writes the output file. I did fond a workaround, though. In an attempt to speed up the facetize process, I reordered the unions of the final combination. In particular, I placed the small objects first and the large objects last. This did speed up the facetize command considerably, and it also fixed the error!

    Gilligan

     
  • Sean Morrison
    Sean Morrison
    2010-06-03

    Glad you found a workaround.  The order of operations can definitely have a big impact on whether tessellation succeeds and how fast it tessellates as the mesh verification is performed at each step along the way and is expensive.