boundary_vertices — 3D mesh_process op

• Data kinds: mesh → indices

• Call: import fullseye as fs; fs.ledger.boundary_vertices(mesh) -> 'np.ndarray' (to call the implementation directly, import mesh_props; mesh_props.boundary_vertices(mesh) -> 'np.ndarray'; from the registry, ops3d.get("boundary_vertices"))

Usage

Indices of the vertices lying on open edges (the boundary) → (K,).

Collects and returns the endpoints of the undirected edges used by exactly 1 face only (boundary edges). For a closed manifold this is an empty array -- that is, len(boundary_vertices(mesh)) == 0 serves as the watertightness test. Hole filling, volume computation and curvature all change meaning depending on whether a boundary exists, so look here first.

Args:

mesh: tuple of (vertices (N,3), faces (M,3)).

Returns:

(K,) int64, ascending and without duplicates. shape == (0,) if there is no boundary.

Raises:

ValueError: when mesh is not the 2 elements (vertices, faces), the shape is invalid,

coordinates are non-finite, an index is non-integer or out of range, or it is empty.

Limitation (honest): what is returned is a set of vertices, not a loop of the rim (in traversal order). Even with several holes everything is merged into 1 array, so if you want them separated per hole you have to trace the connected components yourself (there is no loop-extraction op yet). Non-manifold edges shared by 3 or more faces do not appear here (see non_manifold_edges of mesh_edge_stats).

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)

• mesh_decimate — py -3.11 examples_3d/mesh_decimate.py

• mesh_props — py -3.11 examples_3d/mesh_props.py

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

fuse_to_voxel

Same category (mesh_process)

laplacian_smooth · taubin_smooth · decimate_qem · face_normals · vertex_normals · mesh_area · vertex_curvature · face_areas

*Provenance: mesh_props.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.