brdf_blinn_phong — SPECULAR `reflectance` op

• データ種: normalmap → image2d

• 呼び出し: import specularity; specularity.brdf_blinn_phong(normals, light=(0.0, 0.0, 1.0), view=(0.0, 0.0, 1.0), shininess=32.0) (または opsspecular.get("brdf_blinn_phong"))

使い方

Blinn's half-vector specular lobe. → (H, W) in [0, 1].

`max(n.h, 0) ** shininess where h` is the unit bisector of the light

and view directions (Blinn 1977), zeroed wherever the surface faces away

from either. Exactly 1 where the normal *is* the half-vector — the mirror

condition — and it falls monotonically from there.

Unnormalised on purpose. The classical Blinn-Phong lobe does not

integrate to a fixed value; its peak is 1 and its energy grows as the

exponent shrinks. It is a shading model, useful because its peak location is

exact and because it is a *different* lobe shape from

:func:brdf_microfacet — a separation routine that only works on one of the

two is fitting the lobe, not the model. For an energy-consistent lobe use

:func:brdf_microfacet.

Reciprocal in light and view to machine precision (measured exactly 0.0

maximum difference in `tests/test_specularity.py`), because the

half-vector is symmetric and the visibility test covers both sides.

Raises `ValueError: *normals* is not an (H, W, 3)` field or

contains a zero-length normal; *light* / *view* are not non-zero 3-vectors;

*shininess* is negative, non-finite, a string or a bool; light and view are

exactly opposite.

詳しい使い方ガイド

• specular_photometric ファミリガイド

参考(サンプルデータ・文献)

• サンプルデータカタログ(DL URL / ライセンス) — 2-D は skimage.data(BSD/public)+ 合成、3-D は実データ源(Stanford/PDS 等)の DL URL。

• 演算子の来歴・参考文献 — この op 族の元になった研究/手法の出典。

• アルゴリズムの正典(著者・年)と用途は上記ファミリ使い方ガイドに記載。

実行できる例(この op を実際に呼ぶ検証済みサンプル)

• specular_photometric — py -3.11 examples/specular_photometric.py

型が繋がる次の op(`image2d` を入力に取れる)

polarization_render

同カテゴリ(`reflectance`)

brdf_microfacet · dichromatic_render

*Provenance: specularity.py — SPECULAR operator registry. この per-op ノートは tools/opdocs.py md が自動生成(手編集しない)。*

brdf_blinn_phong — SPECULAR reflectance op

使い方