sample_surface — 3D superquadric op

• Data kinds: vector → points

• Call: import fullseye as fs; fs.ledger.sample_surface(a, eps, n_u: 'int' = 40, n_v: 'int' = 40, R=None, t=None) -> 'np.ndarray' (to call the implementation directly, import superquadric; superquadric.sample_surface(a, eps, n_u: 'int' = 40, n_v: 'int' = 40, R=None, t=None) -> 'np.ndarray'; from the registry, ops3d.get("sample_surface"))

Usage

Sample the surface points of a superquadric parametrically in (eta, omega).

Signed powers such as x = a1 * sgn|cos eta|^eps1 * sgn|cos omega|^eps2 span all 8 octants (eta in [-pi/2, pi/2], omega in [-pi, pi]). The generated points satisfy F = 1 exactly (because cos^2+sin^2=1 cancels the exponents).

Parameters

a, eps : same as inside_outside

n_u : number of samples in the omega (longitude) direction

n_v : number of samples in the eta (latitude) direction

R, t : pose (body→world: X_world = R @ X_body + t)

Returns

np.ndarray, shape (n_u*n_v, 3)

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_lod_download — py -3.11 examples_3d/mesh_lod_download.py

• superquadric_fit — py -3.11 examples_3d/superquadric_fit.py

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

points_to_voxel · gaussians_to_voxel · estimate_point_normals · to_points · match_points_ncc · match_pca · moment_axes · icp_point2point_3d

Same category (superquadric)

fit_superquadric · inside_outside · superquadric_residual


*Provenance: superquadric.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.