estimate_oriented_normals — 3D normals_orient op

• Data kinds: points → normals

• Call: import fullseye as fs; fs.ledger.estimate_oriented_normals(points, k: 'int' = 20, seed_dir=None) -> 'np.ndarray' (to call the implementation directly, import normals_orient; normals_orient.estimate_oriented_normals(points, k: 'int' = 20, seed_dir=None) -> 'np.ndarray'; from the registry, ops3d.get("estimate_oriented_normals"))

Usage

PCA normal estimation combined with Hoppe's global orientation. → oriented unit normals (N,3).

Runs estimate_normals (unoriented) → orient_normals (MST propagation). On a closed surface all points face outward; on a plane all points align to the same hemisphere. Passing the resulting normals to curvature3d.shape_index gives the correct concave/convex sign.

Args:

points: (N,3) point cloud.

k: number of PCA neighbours and kNN graph neighbours (shared).

seed_dir: global reference orientation (3,). If None, outward from the centroid.

Returns:

(N,3) globally consistent, oriented unit normals.

Background guides (the physics and conventions behind this op)

• blender_interop — Using Blender alongside — build the shape, measure it with fullseye (pitfalls: axes, units, ground truth)

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)

• oriented_normals — py -3.11 examples_3d/oriented_normals.py

Ops the type connects to (they accept normals as input)

icp_point2plane · compute_fpfh · shot_descriptor · fuse_to_voxel · reflect · refract · normal_consistency · ransac_cylinder

Same category (normals_orient)

orient_normals


*Provenance: normals_orient.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.