reflectance op• Data kinds: normalmap → rgbimage
• Call: import specularity; specularity.dichromatic_render(normals, albedo_rgb=(0.8, 0.55, 0.35), light=(0.3, 0.2, 1.0), illuminant_rgb=(1.0, 1.0, 1.0), view=(0.0, 0.0, 1.0), specular=0.25, model='blinn_phong', shininess=32.0, roughness=0.3, f0=0.04, ambient=0.0) (or opsspecular.get("dichromatic_render"))
Forward dichromatic model: render a known highlight so a separation can be checked against it. → (H, W, 3).
`I = albedo_rgb * max(n.l, 0) + specular * lobe(n) * illuminant_unit`, the
body term coming straight from :func:photometric.render_lambertian (called,
not re-implemented, so the two modules cannot drift apart in convention) and
the interface term carrying the illuminant colour, which is what makes
the image obey the dichromatic model exactly.
*albedo_rgb* may be a single `(3,)` colour — the single-material case that
:func:specular_diffuse_split handles without help — or an `(H, W, 3)`
map, which is the textured case that needs `body_rgb` passed to the split.
*model* selects the lobe: `"blinn_phong"` (*shininess*) or
`"microfacet"` (*roughness*, *f0*). Both are available on purpose: the
separation operators must be blind to the lobe shape, and swapping the model
is how that is tested rather than asserted.
This is a shading model, not light transport. No interreflection, no
cast shadow, no subsurface term, no occlusion between pixels — the same
boundary :mod:visiondesign draws. Its purpose is a synthetic image whose
decomposition is known exactly.
Raises `ValueError`: geometry problems as in
:func:brdf_blinn_phong; *albedo_rgb* is neither `(3,)` nor
`(H, W, 3)`; *specular* or *ambient* is negative, non-finite, a string or
a bool; *model* is not in :data:BRDF_MODELS.
• specular_photometric family guide
• 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 canonical algorithm (author, year) and its uses are named in the family usage guide above.
• specular_photometric — py -3.11 examples/specular_photometric.py
rgbimage as input)specular_diffuse_split · specular_coefficient_map · specular_free_transform · illuminant_from_dichromatic_planes
reflectance)brdf_blinn_phong · brdf_microfacet
*Provenance: specularity.py — SPECULAR 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.