fit_circle_3d — 3D geometry op

Data kinds: pointsprimitive

Call: import fullseye as fs; fs.ledger.fit_circle_3d(points) (to call the implementation directly, import match3d; match3d.fit_circle_3d(points); from the registry, ops3d.get("fit_circle_3d"))

Usage

Point set → a 3-D circle (fit the plane, then fit a 2-D circle within it). Returns (center, radius, normal).

> The detailed description below is the original text — the summary and the headings are translated.

`fit_plane_3d で面 (c, n) を取り、面内の正規直交基底 (e1, e2)` に点を射影して 2-D の

代数円フィット(`|q|² = 2·cc·q + klstsq)を解き、中心を 3-D に戻す。(N,3)` で

3 点未満は ValueError(3 点なら面は厳密、円は 3 点を通る)。

`center は面上の 3-D 点、radius は float(負の根は 0 に clamp)、normal` は面の単位法線

(符号任意)。円弧の一部だけ・面から外れた点が多いと半径が偏る(代数フィットの性質。面内残差は

返さない)。

用途: 穴・フランジ・リングの中心と径、`distance_point_line` で軸からの偏心。

References (sample data, literature)

• 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.

Runnable examples (verified samples that actually call this op)

geometry_metrologypy -3.11 examples_3d/geometry_metrology.py

Ops the type connects to (they accept 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

Same category (geometry)

line_from_2points · plane_from_3points · angle_3points · angle_between_lines · angle_between_planes · angle_line_plane · distance_point_plane · distance_point_line


*Provenance: match3d.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.