fullseye

form_factor_perpendicular_rects — OPTICS radiosity op

使い方

View factor from a rectangle w × l to a rectangle h × l sharing the edge of length l at 90° (Howell’s catalogue C-14, closed form).

With H = h/l and W = w/l (surface 1 is the w side, surface 2 the h side)::

F_12 = 1/(π W) ( W atan(1/W) + H atan(1/H) − √(H²+W²) atan(1/√(H²+W²))
       + ¼ ln{ (1+W²)(1+H²)/(1+W²+H²)
               · [W²(1+W²+H²)/((1+W²)(W²+H²))]^(W²)
               · [H²(1+H²+W²)/((1+H²)(H²+W²))]^(H²) } )

H = W = 1 (two unit squares on a common edge) gives 0.200044. Reciprocity: w F_12 = h F_21 (form_factor_perpendicular_rects(w, h, l) is F_21).

Returns the view factor F_12 (measurement).

Raises ValueError: a non-positive or non-finite length.

ファミリ共通の入力契約(fail-closed)

optics の全 op は入力を検証してから計算する(黙って通さない):

詳しい使い方ガイド

参考(サンプルデータ・文献)

実行できる例(この op を実際に呼ぶ検証済みサンプル)

型が繋がる次の op(measurement を入力に取れる)

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同カテゴリ(radiosity)

form_factor_parallel_rects · form_factor_polygons · radiosity_patches · form_factor_matrix · radiosity_progressive_3d · render_optscene_gi


Provenance: radiosity3d.py — OPTICS 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)。

© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.