render_lambertian — 3D photometric op

Data kinds: normalmapimage2d

Call: import fullseye as fs; fs.ledger.render_lambertian(normals, albedo, light, ambient=0.0) (to call the implementation directly, import photometric; photometric.render_lambertian(normals, albedo, light, ambient=0.0); from the registry, ops3d.get("render_lambertian"))

Usage

Normals + albedo + light direction → a Lambertian image (inspection-sample generation / GT verification / the forward model of inverse rendering). → HxW.

> The detailed description below is the original text — the summary and the headings are translated.

`I = albedo * (max(n·L, 0) + ambient)light` は (3,) の光源方向ベクトルで内部で

単位長に正規化する(長さは強度として効かない)。`n·L < 0` の画素は 0 にクリップ

される(付着影)。`ambient` は法線に依らず一様に足す定数で、アルベドは掛かる

(既定 0)。`normals(H,W,3) の法線(単位長を仮定し正規化しない)、albedo`

は `(H,W) またはブロードキャスト可能な配列・スカラ。返り値は float32 の (H,W)`。

上限は `albedo * (1 + ambient)` で、[0,1] へのクリップはしない。入力検証は無い。

`photometric_stereo の順方向モデルそのもの(光源正規化の規約は normalize=True`

に対応)なので、復元した法線・アルベドから再合成して元画像と比べる往復検証に使える。

鏡面・相互反射・投影影(cast shadow)は含まない。

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)

photometric_stereopy -3.11 examples_3d/photometric_stereo.py

render_shadepy -3.11 examples_3d/render_shade.py

Ops the type connects to (they accept image2d as input)

fuse_to_voxel · fit_poly_surface · eval_poly_surface · surface_form_error · background_flatten · polar_unwrap · fit_zernike · matcap_shade

Same category (photometric)

photometric_stereo · surface_normals · integrate_normals


*Provenance: photometric.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.