typed op• Data kinds: points → volume
• Call: fullseye.apply(img, "tb_sphere_sdf", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])
*The figure is the actual output on a synthetic 128×128 input. Left: input, right: output. Point clouds are drawn as a top-down scatter (brightness = z), 1-D series as a line plot, volumes as the maximum-intensity projection along z, videos as the middle frame, complex images as magnitude; return values that are not pictures are shown as the values themselves.*
*Knob a does not change the output (measured: identical at 0.1 / 0.5 / 0.9).*
*Knob b does not change the output (measured: identical at 0.1 / 0.5 / 0.9).*
Stages (the ops that come before → this op, left to right):
▸ tb_sphere_sdf: stages (docs site)
On other images (synthetic scene / photo / coins. Top row: inputs, bottom row: their outputs. Knobs at default):
▸ tb_sphere_sdf: other inputs (docs site)
Motion (GIF: frames / views / slices in turn. The still figure is the complete one; the GIF is supplementary):
Signed distance field of a sphere: `|p - center| - R` (negative inside, positive outside).
> The detailed description below is the original text — the summary and the headings are translated.
`grid は最終軸が 3 の座標配列 (..., 3)(grid_coords` の出力や (N,3) 点群)。
`center は長さ3、R>=0 は半径。返り値の shape は grid.shape[:-1]`。厳密な SDF
(勾配ノルム 1)。`sdf_offset(sphere_sdf(g,c,R), r) == sphere_sdf(g,c,R+r)`。
Raises ValueError for R<0 or malformed grid/center。
計算: `np.linalg.norm(grid - center, axis=-1) - R`。座標の単位はそのまま距離の
単位になる(`grid_coords` の world 座標を渡せば world 単位)。座標の成分順は
`grid の最終軸の順(grid_coords なら (x, y, z))で、center` も同じ順。
引数と検証(`ValueError`):
• `grid: 最終軸が 3 の float 配列 (..., 3)(1-D の (3,)` も可。0-D や
最終軸が 3 以外は拒否)。
• `center: 要素数 3(reshape(3) できなければ numpy の ValueError`)。
• `R: float() できるスカラ。回転行列などを渡した場合も ValueError`
(この引数は半径であって姿勢ではない)。`R < 0 は拒否、R = 0` は
中心からの距離場そのもの。
返り値: `grid.shape[:-1] の float64(grid_coords` の出力なら
`(nx, ny, nz))。中心で -R`、表面で 0、外側で正。
使いどころ: `grid_coords で格子 → sphere_sdf / box_sdf → sdf_union` /
`sdf_subtract で CSG → <= 0 を占有として marching cubes(voxel_to_mesh`
に `-sdf を渡し iso=0` 相当で等値面)。
2-D 進化レジストリへ橋渡しした 3d の op `sphere_sdf。実装は同じで、呼び出し規約だけ op(v, a, b) に合わせてある。この op に調整点は無く、a も b` も使われない。
• 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.
The program below has been verified to run (same input as the figure). In Studio's help this block becomes buttons that load and run it on the spot.
img_to_points 0.50 0.50 tb_sphere_sdf 0.50 0.50
▸ Load this pipeline · Load & run
The examples below call the underlying ledger op sphere_sdf. This bridge op is the same implementation adapted to the fn(v, a, b) convention, so the behaviour carries over unchanged (only the call form differs).
• annotate3d_figure — py -3.11 examples_3d/annotate3d_figure.py
• gear_metrology — py -3.11 examples_3d/gear_metrology.py
• molecule_atom_count — py -3.11 examples_3d/molecule_atom_count.py
• procedural_hand — py -3.11 examples_3d/procedural_hand.py
• render_beauty — py -3.11 examples_3d/render_beauty.py
• sdf_csg — py -3.11 examples_3d/sdf_csg.py
• sfm_recon — py -3.11 examples_3d/sfm_recon.py
volume as input)identity · vol_gaussian · vol_median · vol_erode · vol_dilate · vol_threshold · vol_reg_dilate · vol_reg_erode
typed)tb_points_to_voxel · tb_estimate_point_normals · tb_iss_keypoints · tb_project_points · tb_render_point_depth · tb_statistical_outlier_removal · tb_radius_outlier_removal · tb_voxel_grid_downsample
*Provenance: ops.py — 2D 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.