terrain opmesh → matriximport fullseye as fs; fs.ledger.displacement_band_weights(V, F, wavelengths=(0.06, 0.03, 0.015, 0.0075, 0.00375), *, nyquist: 'float' = 2.0, fade: 'float' = 1.0, local_edge=None) -> 'np.ndarray' (実装を直接呼ぶなら import render3d; render3d.displacement_band_weights(V, F, wavelengths=(0.06, 0.03, 0.015, 0.0075, 0.00375), *, nyquist: 'float' = 2.0, fade: 'float' = 1.0, local_edge=None) -> 'np.ndarray'、台帳から引くなら ops3d.get("displacement_band_weights"))Per-octave, per-vertex band gate (K, N) in [0,1]: 1 where the mesh can carry the
wavelength as geometry, 0 where it would alias.
A vertex with local edge length e (mean incident edge, :func:mesh_edge_lengths,
or local_edge (N,) if given) carries wavelength λ only when λ ≥ nyquist·e;
the gate rises linearly from 0 at λ = nyquist·e to 1 at λ = (nyquist+fade)·e
(fade=0 → hard cut). Used two ways by the Itokawa pipeline: (i) on the rendered
mesh to decide which octaves may be displaced (the rest go to bump normals); (ii) on
the source model to measure which wavelengths the real data already carries — the
complement 1 − gate is the synthetic-relief weight (0 where the data are fine,
1 where they are coarse), so dense regions are not double-textured. Deterministic.
計算は ratio = λ_k / e_i に対し、fade == 0 なら gate = (ratio ≥ nyquist) の
二値、それ以外は gate = clip((ratio − nyquist) / fade, 0, 1)。返り値は float64
(K, N)(K = 波長数、N = 頂点数)。
wavelengths: メッシュ単位の波長列(空・非正・非有限は ValueError)。
mesh_displace_spectrum と同じ列を渡す。nyquist: 「幾何として担える」と見なす波長/辺長比の下限(既定 2 = 1 波長に
2 辺)。0 以下は ValueError。fade: 遷移幅(辺長の倍数)。0 で硬い閾値。負は ValueError。local_edge: 頂点ごとの辺長 (N,) を自分で与える場合(mesh_edge_lengths の
per='vertex' 相当)。長さ不一致・非正・非有限は ValueError。None なら
内部で :func:mesh_edge_lengths を呼ぶ。mesh_displace_spectrum は内部でこの関数を呼ぶので、通常は直接呼ぶ必要はない。直接
使うのは、元データが既に担っている波長を測って 1 − gate を weights として渡す
(細かい所に合成起伏を二重に載せない)ときと、bump_normals_fbm へ回す残りを
決めるとき。
py -3.11 examples_3d/itokawa_regolith_hero.pymatrix を入力に取れる)terrain)mesh_displace_fbm · terrain_region_mask · mesh_scatter_boulders · mesh_edge_lengths · mesh_subdivide · mesh_displace_spectrum · bump_normals_fbm
Provenance: render3d.py — 3D 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.