segment op• Data kinds: points → labels
• Call: import fullseye as fs; fs.ledger.region_growing(points, normals=None, angle_thresh_deg: 'float' = 15.0, k: 'int' = 20, min_region_size: 'int' = 3) -> 'np.ndarray' (to call the implementation directly, import segment3d; segment3d.region_growing(points, normals=None, angle_thresh_deg: 'float' = 15.0, k: 'int' = 20, min_region_size: 'int' = 3) -> 'np.ndarray'; from the registry, ops3d.get("region_growing"))
Grow regions by normal similarity and give the connected smooth regions the same label (the variant without a curvature gate).
Grows each point by BFS on the k-nearest-neighbour graph, adding a neighbour q to the same region only when "the angle between normals n_p and n_q is below angle_thresh_deg". Normals within a plane are nearly parallel, so they connect into the same region; at boundaries between faces of different orientation the angle opens and the connection breaks → a separate region per face. Normals have an undetermined sign (they come from PCA), so the test uses |n_p·n_q| (front and back are treated as the same).
Args:
points: (N,3) point cloud.
normals: (N,3) unit normals. If None, estimated by PCA with pointcloud.estimate_normals.
angle_thresh_deg: upper tolerance for the angle between neighbouring normals [degrees]. Range (0,180).
k: number of neighbours (degree of the kNN graph).
Returns:
labels: (N,) int. Assigns 0,1,2,... per connected smooth region. Small regions below min_region_size (isolated points, debris with inconsistent orientation) are -1 (noise/unassigned), following the unified contract (-1=noise).
Empty input returns shape (0,).
• 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.
• sensor_seg — py -3.11 examples_3d/sensor_seg.py
labels as input)fuse_to_voxel · vol_region_props
segment)euclidean_cluster · plane_segmentation · vol_watershed
*Provenance: segment3d.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.