ORF ring construction: (a) F out facets (dark) on the contour E
: ( v
, … v
). The F gap facets (clear) bridge the gap between pairs of consecutive F out facets. (b) Extraction of the new F out facets. Notice that the new F out facets are one-to-one adjacent to the F gap facets. (c) The Fin and F out facets. (d) Extraction of the F gap facets. (e) The facet ring, obtained by grouping the F out and F gap facets, is displayed with color mapping reflecting the circular arrangement of the facets. (f) The NewFout facets.