def flip(script, force_flip=False, selected=False):
filter_xml = '<STR_LIT>'.join([<EOL>'<STR_LIT>',<EOL>'<STR_LIT>',<EOL>'<STR_LIT>'.format(str(force_flip).lower()),<EOL>'<STR_LIT>',<EOL>'<STR_LIT>',<EOL>'<STR_LIT>',<EOL>'<STR_LIT>',<EOL>'<STR_LIT>'.format(str(selected).lower()),<EOL>'<STR_LIT>',<EOL>'<STR_LIT>',<EOL>'<STR_LIT>',<EOL>'<STR_LIT>'])<EOL>util.write_filter(script, filter_xml)<EOL>return None<EOL>
Invert faces orientation, flipping the normals of the mesh.

    If requested, it tries to guess the right orientation; mainly it decides to
    flip all the faces if the minimum/maximum vertexes have not outward point
    normals for a few directions. Works well for single component watertight
    objects.

    Args:
        script: the FilterScript object or script filename to write
            the filter to.
        force_flip (bool): If selected, the normals will always be flipped;
            otherwise, the filter tries to set them outside.
        selected (bool): If selected, only selected faces will be affected.

    Layer stack:
        No impacts

    MeshLab versions:
        2016.12
        1.3.4BETA