symmetry op• Data kinds: points → primitive
• Call: import fullseye as fs; fs.ledger.detect_rotational_symmetry(points, orders=(2, 3, 4, 6, 8)) (to call the implementation directly, import symmetry3d; symmetry3d.detect_rotational_symmetry(points, orders=(2, 3, 4, 6, 8)); from the registry, ops3d.get("detect_rotational_symmetry"))
Choose the best rotational symmetry (axis × order) with the PCA principal axes as candidate axes.
→ dict{axis_point, axis_dir, order, score, table, margin}. The smaller the score, the more symmetric.
★ Always read margin (the difference from 2nd place) alongside. The reason is the same as for detect_reflection_symmetry: if the candidates are bunched, the choice is a lottery, and what collapses first then is the margin, not the score. For rotational symmetry the candidates are 3 axes x order, so a different order of the same axis often comes 2nd, and in that case a small margin means "the order is undetermined" (the axis is determined). table holds all candidates, so you can fix only the axis and re-examine the order.
★ The candidates are only the 3 PCA axes. For a shape whose true symmetry axis matches none of the principal axes, the axis is not found, and the op silently returns the best anyway.
• Sample-data catalog (download URLs / licences) — 2-D uses skimage.data (BSD/public domain) plus synthetic images; 3-D lists download URLs for real data sources (Stanford, PDS, …).
• Operator provenance and references — the sources of the research/methods this op family came from.
• rotational_symmetry_fold — py -3.11 examples_3d/rotational_symmetry_fold.py
• symmetry — py -3.11 examples_3d/symmetry.py
primitive as input)fuse_to_voxel · angle_between_lines · angle_between_planes · angle_line_plane · distance_point_plane · distance_point_line · distance_line_line · distance_segment_segment
symmetry)detect_reflection_symmetry · reflect_points · reflection_symmetry_score
*Provenance: symmetry3d.py — 3D operator registry. This per-op note is generated by tools/opdocs.py md (do not hand-edit).*
© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.