light_transport op• Data kinds: table → table
• Call: import fullseye as fs; fs.ledger.tof_transport_depth(transport, camera_xz=(0.0, 1.0), modulation_hz=20000000.0, n_bounces=None) (to call the implementation directly, import lighttransport; lighttransport.tof_transport_depth(transport, camera_xz=(0.0, 1.0), modulation_hz=20000000.0, n_bounces=None); from the registry, opsoptics.get("tof_transport_depth"))
AMCW time-of-flight depth of a concave Lambertian cross-section (a room corner) with every interreflection delayed by its path length: complex radiosity, per-pixel depth bias.
The source sits at the camera (*camera_xz*, a line source in 2-D) and lights patch j with ρ_j cos_j / r_j · e^{i k r_j}, k = 2π f / c. Each hop j → i multiplies by F_ij e^{i k R_ij} (R_ij = centre distance), so B = (I − diag(ρ)(F ∘ e^{ikR}))^-1 diag(ρ) E (or the Neumann sum up to *n_bounces* hops); the pixel sees B_i e^{i k r_i}. Depth is c φ / (4π f); truth is r_i. Patches must be small next to the modulation wavelength.
*transport* from transport_matrix_radiosity supplies the profile, form factors and albedo; the camera must be inside the concave region (above the profile, between its ends) so that every patch faces it.
Returns a dict (a table): depth, true_depth, bias (from the wrapped phase difference), direct_amplitude, global_amplitude, ratio, x (patch centres) and ambiguity_range.
Raises ValueError: not a transport table; *camera_xz* not two finite numbers inside the region or a patch facing away from it; *modulation_hz* outside (0, 1e10]; *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 · transport_matrix_radiosity · high_frequency_patterns · render_transport · separate_direct_global · fringe_multipath_phase_error · predict_fringe_phase_error
*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.