light_transport op• Data kinds: table → table
• Call: import fullseye as fs; fs.ledger.transport_matrix_radiosity(profile, albedo=0.8, n_bounces=None) (to call the implementation directly, import lighttransport; lighttransport.transport_matrix_radiosity(profile, albedo=0.8, n_bounces=None); from the registry, opsoptics.get("transport_matrix_radiosity"))
Light-transport matrix of a Lambertian concave cross-section: radiosity B = T E with T = (I − diag(ρ)F)^-1 diag(ρ).
The radiosity equation B = ρ E + ρ F B (E = irradiance from the projector, F from form_factors_2d) is solved for the matrix that maps any irradiance pattern to the radiosity the camera sees. The direct part is diag(ρ); everything else is global (interreflection).
*albedo* is a scalar or one value per patch, each in [0, 1). *n_bounces* None solves exactly; an integer k >= 0 returns the Neumann partial sum Σ_{m<=k} (diag(ρ)F)^m diag(ρ) — light that has bounced at most k times between patches (0 = direct only).
Returns a dict (a table) with kind = "lt_transport", transport (P, P), direct (P,) = the diagonal direct part ρ, albedo, form_factors, opening_form_factors (P,), n_bounces, gain_bound = max_i ρ_i Σ_j F_ij (< 1, bounds the Neumann series) and the profile.
Raises ValueError: not a groove_profile table; an albedo outside [0, 1), non-finite, or of the wrong length; *n_bounces* not None or an integer in [0, 10000].
Every optics op validates its input before computing (nothing slips through silently):
• Units are baked into the argument name — _mm / _um / _deg / _mrad. Confusing mm with µm does not crash; it yields a plausible-looking wrong answer, so the name prevents it. Nothing here guesses the unit from the magnitude.
• Strings raise ValueError — float('50') succeeds, so an unparsed configuration value would slip through as a length (measured: thin_lens('50', '200') returned a plausible 66.667 mm). bool is refused too, as the implicit promotion True == 1.
• complex / masked arrays raise ValueError (real-valued slots only; silently dropping the imaginary part or peeling off the mask is refused). NaN/Inf raises ValueError on every input.
• Division by zero and its relatives are refused by name: focal length 0, radius of curvature 0, refractive index <= 0, a fully opaque aperture (all zeros, so the normalisation is 0/0), a PSF whose sum is <= 0, a Stokes vector with S0 = 0, and an object sitting at the front focal point (the image is at infinity).
• Only two ops return a non-finite value, and both state it as a contract: depth_of_field returns far_mm = inf beyond the hyperfocal distance (that is what the hyperfocal distance means), and gaussian_beam returns wavefront_radius_mm = inf at the waist (the radius of curvature of a plane wavefront). Both also return a finite companion (far_is_infinite / curvature_per_mm). Any other silent NaN/Inf is detected internally and raises ValueError — "float64 overflowed" and "the answer is infinite" are different claims, so the first is never returned wearing the face of the second.
• Size caps: generated grids are capped by optics.MAX_GRID (4096); supplied fields/PSFs/apertures by optics.MAX_FIELD_ELEMENTS (2^24); ABCD element chains by optics.MAX_SYSTEM_ELEMENTS (1024); Zernike by MAX_ZERNIKE_TERMS (512) / MAX_ZERNIKE_ORDER (40) / MAX_ZERNIKE_BASIS (2^25). This closes, fail-closed, the paths where a small argument triggers a huge internal allocation (measured: n_max=40 × 4096² needs 108 GB).
• Physically impossible states are refused too: a Stokes vector with degree of polarisation > 1, negative transmittance, negative intensity, and invalid Zernike indices such as n-|m| odd.
• 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.
• poc_interreflection_fringe_error — py -3.11 examples/poc_interreflection_fringe_error.py
• poc_itof_multifreq — py -3.11 examples/poc_itof_multifreq.py
table as input)abcd_matrix · wavefront_stats · sfr_from_edge · paraxial_trace · seidel_coefficients · spot_stats · tolerance_analysis · wavefront_from_opd
light_transport)groove_profile · form_factors_2d · high_frequency_patterns · render_transport · separate_direct_global · fringe_multipath_phase_error · predict_fringe_phase_error · micro_phase_decode
*Provenance: lighttransport.py — OPTICS 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.