{"schema":"https://ver.cy/schemas/card/1.0.0","id":"vr.tr.light-field","code":"thing-q593161","url":"https://ver.cy/models/thing/q593161/","name":"light field","alternateNames":[],"kind":"thing","status":"published","version":"0.1.0-research.1","language":"en","classifiers":{"family":"Thing Registry","category":"Cross-cutting context","entryKind":"thing","plane":"XCT","domain":["XCT.QLT"],"industry":[],"navPath":"","tags":[],"facets":{}},"whatItIs":"A light field describes the radiance of light as a function of position and propagation direction, usually at a fixed time and wavelength or over a specified spectral band.","purpose":"Enable an agent to recognise a light field, assess its directional and spatial coverage, and decide which viewing, refocusing or measurement operations its evidence supports.","scope":{"in":["Definitions distinguishing a general position-and-direction radiance function from a reduced four-dimensional ray representation","Ray coordinates, spatial boundaries, directional coverage and propagation assumptions","Spectral, temporal and radiometric interpretation of field values","Measured, simulated and inferred light-field samples and their calibration","Conditions supporting view synthesis, computational refocusing and geometric inference"],"out":["Construction and operation of plenoptic cameras, camera arrays and light-field displays","Full electromagnetic fields, optical phase and wave-interference models","Scene geometry, material reflectance and illumination sources as independently modelled entities","Neural-network architectures and volumetric scene representations used to generate ray observations","Image-file formats, storage infrastructure and compression implementations"],"boundaries":[]},"distinguishingFeatures":["A light-field representation associates values with both ray position and ray direction; a conventional photograph alone does not establish independently sampled variation across both.","An environment map records directional appearance from a reference location or under an explicit distant-scene approximation; it does not generally establish spatially varying ray values.","A depth map records geometric distance rather than directional radiance, even when both are derived from the same capture.","A radiance light field does not by itself record optical phase or the electric and magnetic field components needed for wave-optics analysis.","A model must declare whether its values describe radiance along rays or local emission and attenuation that require a transport calculation to produce ray observations."],"structure":{"bundles":[{"id":"definition-and-instance","name":"Definition and instance","description":"Establish which meaning of light field applies and what constitutes an instance.","layers":[{"id":"radiance-convention","name":"Radiance convention","description":"Identify the quantity and independent variables used by the adopted definition.","findings":[{"id":"position-direction-definition","name":"Position-direction definition","description":"Record the adopted radiance definition and its authority. Levoy and Hanrahan define light fields through position and direction: [Light Field Rendering](https://www.graphics.stanford.edu/papers/light/).","questions":[{"text":"Which definition and source govern this instance, and what quantity does the function return?","id":"position-direction-definition-q01","kind":"definition"},{"text":"Are wavelength and time explicit coordinates, fixed conditions or integrated variables?","id":"position-direction-definition-q02","kind":"boundary"}]}]},{"id":"instance-boundaries","name":"Instance boundaries","description":"Separate the field being described from its captures and computational encodings.","findings":[{"id":"field-versus-representation","name":"Field versus representation","description":"Record whether an instance denotes a physical radiance distribution, a sampled observation or an inferred representation, and how these are related.","questions":[{"text":"Does this instance denote the optical distribution, a particular capture or a reconstruction?","id":"field-versus-representation-q01","kind":"definition"},{"text":"Which changes in scene, illumination or time create a different field instance?","id":"field-versus-representation-q02","kind":"boundary"}]}]}]},{"id":"ray-domain-and-transport","name":"Ray domain and transport","description":"Specify ray identities, coverage and the physical assumptions behind their use.","layers":[{"id":"ray-coordinate-system","name":"Ray coordinate system","description":"Describe how coordinates identify oriented rays.","findings":[{"id":"coordinate-interpretation","name":"Coordinate interpretation","description":"Record reference frames, orientation, units and any reference planes needed to interpret ray coordinates.","questions":[{"text":"How does a sample address map to a physical ray, including its direction of travel?","id":"coordinate-interpretation-q01","kind":"definition"},{"text":"Which rays are excluded or singular under the chosen parameterisation?","id":"coordinate-interpretation-q02","kind":"boundary"}]}]},{"id":"transport-assumptions","name":"Transport assumptions","description":"State where a reduced ray representation is valid.","findings":[{"id":"four-dimensional-reduction","name":"Four-dimensional reduction","description":"Record the region supporting a four-dimensional ray representation and the assumptions permitting position along a ray to be omitted. The classic formulation uses free-space regions: [Light Field Rendering](https://graphics.stanford.edu/projects/lightfield/gamma-corrected/).","questions":[{"text":"What evidence supports treating radiance as invariant along the represented ray segments?","id":"four-dimensional-reduction-q01","kind":"boundary"},{"text":"Where do occlusion, attenuation, emission, scattering or refraction invalidate the adopted transport simplification?","id":"four-dimensional-reduction-q02","kind":"boundary"}]}]}]},{"id":"radiometric-spectral-temporal-meaning","name":"Radiometric, spectral and temporal meaning","description":"Make light-field values comparable and physically interpretable.","layers":[{"id":"radiometric-values","name":"Radiometric values","description":"Track units, response corrections and unusable measurements.","findings":[{"id":"radiance-or-encoded-values","name":"Radiance or encoded values","description":"Require an explicit distinction between physical radiance and relative or display-encoded channel values.","questions":[{"text":"What units, exposure normalisation and response transformation define each value?","id":"radiance-or-encoded-values-q01","kind":"measurement"},{"text":"Which samples are clipped, below the noise floor or affected by unresolved gain differences?","id":"radiance-or-encoded-values-q02","kind":"measurement"}]}]},{"id":"spectral-temporal-compatibility","name":"Spectral and temporal compatibility","description":"Describe the wavelength and time intervals contributing to samples.","findings":[{"id":"compatible-ray-observations","name":"Compatible ray observations","description":"Record whether observations can be treated as samples of one field under the intended use.","questions":[{"text":"Which spectral responses and exposure intervals contribute to each group of ray samples?","id":"compatible-ray-observations-q01","kind":"measurement"},{"text":"What evidence supports combining sequential views despite possible scene motion or illumination change?","id":"compatible-ray-observations-q02","kind":"provenance"}]}]}]},{"id":"sampling-and-reconstruction-evidence","name":"Sampling and reconstruction evidence","description":"Describe observed ray support and the evidence behind reconstructed values.","layers":[{"id":"ray-sampling-support","name":"Ray sampling support","description":"Record sampling density, footprints and coverage gaps.","findings":[{"id":"measured-ray-coverage","name":"Measured ray coverage","description":"Describe the actual spatial-angular sample pattern, including finite integration footprints and missing observations.","questions":[{"text":"What are the spatial and angular sample spacings and footprints across the supported domain?","id":"measured-ray-coverage-q01","kind":"measurement"},{"text":"Which requested rays fall between measured samples or outside observed coverage?","id":"measured-ray-coverage-q02","kind":"boundary"}]}]},{"id":"calibration-and-inference","name":"Calibration and inference","description":"Connect ray assignments and reconstructed values to their supporting evidence.","findings":[{"id":"sample-lineage-and-error","name":"Sample lineage and error","description":"Record geometric calibration, value provenance and validation for measured, simulated, interpolated or learned samples.","questions":[{"text":"Which calibration records establish ray locations and directions, and with what residual error?","id":"sample-lineage-and-error-q01","kind":"provenance"},{"text":"Which values are inferred, and what held-out observations or other evidence bound their error?","id":"sample-lineage-and-error-q02","kind":"measurement"}]}]}]},{"id":"supported-operations","name":"Supported operations","description":"Determine which transformations and inferences the particular field can support.","layers":[{"id":"view-and-aperture-queries","name":"View and aperture queries","description":"Assess requested viewpoints and computational focus settings against available rays.","findings":[{"id":"rendering-query-admissibility","name":"Rendering query admissibility","description":"Record the ray support and validation required for a requested viewpoint, focus setting and synthetic aperture.","questions":[{"text":"Do the requested viewpoint and aperture require rays outside the calibrated support?","id":"rendering-query-admissibility-q01","kind":"action"},{"text":"Which focus and aperture settings meet the task's stated sharpness and artifact tolerances?","id":"rendering-query-admissibility-q02","kind":"measurement"}]}]},{"id":"geometric-inference","name":"Geometric inference","description":"Assess what directional variation permits an agent to infer about scene structure.","findings":[{"id":"disparity-and-depth-conditions","name":"Disparity and depth conditions","description":"Require geometric inference to state its calibration, correspondence and appearance assumptions and identify ambiguous regions.","questions":[{"text":"Which calibration and correspondence assumptions support converting angular variation into disparity or metric depth?","id":"disparity-and-depth-conditions-q01","kind":"definition"},{"text":"Where do occlusion, weak texture, reflections or transparency make the inferred geometry ambiguous?","id":"disparity-and-depth-conditions-q02","kind":"boundary"},{"text":"Should the agent return an uncertainty interval, request additional views or withhold a depth estimate?","id":"disparity-and-depth-conditions-q03","kind":"action"}]}]}]},{"id":"evidence-and-external-alignment","name":"Evidence and external alignment","description":"What the world already says about this thing, gathered so the model can be checked against it.","layers":[{"id":"reported-evidence","name":"Reported evidence","description":"Findings from the breadth pass, kept separate from the structural claims.","findings":[{"id":"evidence-confidence-notes","name":"Check these first","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these check these first hold for the sense of light field this model covers, and on what evidence?","id":"evidence-confidence-notes-q01","kind":"provenance"}]},{"id":"evidence-kinds","name":"Kinds and varieties","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these kinds and varieties hold for the sense of light field this model covers, and on what evidence?","id":"evidence-kinds-q01","kind":"provenance"}]},{"id":"evidence-real-world-use","name":"Real-world use","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these real-world use hold for the sense of light field this model covers, and on what evidence?","id":"evidence-real-world-use-q01","kind":"provenance"}]},{"id":"evidence-measurements","name":"Typical measurements","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these typical measurements hold for the sense of light field this model covers, and on what evidence?","id":"evidence-measurements-q01","kind":"provenance"}]},{"id":"evidence-failure-modes-and-hazards","name":"Failure modes and hazards","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these failure modes and hazards hold for the sense of light field this model covers, and on what evidence?","id":"evidence-failure-modes-and-hazards-q01","kind":"provenance"}]},{"id":"evidence-neighbours","name":"Neighbouring kinds and how to tell them apart","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these neighbouring kinds and how to tell them apart hold for the sense of light field this model covers, and on what evidence?","id":"evidence-neighbours-q01","kind":"provenance"}]}]}]}]},"agentConduct":{"may":["Explain the light field concept and its use in imaging, rendering and displays.","Capture or process light field data the agent is authorized to handle."],"mustNot":["Capture light field images of people without their consent where consent is required.","Use refocusing or depth recovery to reveal details people meant to keep out of view.","Present synthetic views from light field data as unaltered photographs."],"requiresHuman":["Using light field capture in surveillance or identification of people."]},"ethics":{"considerations":["Light field capture records depth and multiple views, making images more revealing than ordinary photographs.","Synthetic views can be mistaken for real scenes."],"affectedParties":["People captured in images","Viewers","Researchers"]},"owners":{"steward":"Nobody owns it; it is a concept of optics.","roles":[],"masterSystems":[]},"relations":[{"target":"Q11348","type":"parent","note":"registry parent class"}],"interaction":{"identity":{"applicability":"required","items":["Vercy registry: vr.tr.light-field","Wikidata: Q593161 (https://www.wikidata.org/wiki/Q593161)"]},"properties":{"applicability":"not-applicable","items":["Definition and retained dimensions: Position-direction function; four-dimensional ray function; declared spectral or temporal extension","Ray parameterisation: Position plus direction; two-plane coordinates; another explicitly defined ray chart","Spatial and angular support: Spatial extent in m; directions in rad or unit vectors; supported solid angle in sr","Radiometric interpretation: Band-integrated radiance in W m^-2 sr^-1; spectral radiance with declared wavelength unit; calibrated channel values; relative encoded values","Sampling footprint: Spatial and angular spacing and integration footprints, with units defined by the ray chart","Temporal and spectral support: Capture times and exposure intervals in s; wavelength bands in nm; channel response functions","Propagation regime: Declared homogeneous transparent region; participating medium; refractive region; unresolved","Sample evidence origin: Links from ray samples or regions to measurements, simulation runs, reconstruction methods and calibration records","Operational validity: Supported, conditionally supported, unsupported or unassessed for each requested operation"]},"recognition":{"applicability":"not-applicable","items":[]},"capabilities":{"applicability":"required","items":["Query directional radiance or channel values at supported ray coordinates.","Reparameterise rays while recording coverage loss and resampling effects.","Synthesize viewpoints with explicit limits on interpolation and extrapolation.","Compute refocused images or aperture integrations where ray coverage permits.","Estimate disparity or depth with stated correspondence assumptions and uncertainty.","Identify missing ray coverage and specify additional capture requirements."]},"hazards":{"applicability":"required","items":["Sampling errors cause artefacts that can be mistaken for real details.","Large datasets raise storage and privacy risks."]},"interfaces":{"applicability":"required","items":["The International Commission on Illumination publishes CIE S 017/E:2020, the International Lighting Vocabulary, which standardizes radiometric terminology including radiance."]},"context":{"applicability":"required","items":["Light fields are used in computational photography, optical measurement and computer graphics to describe how radiance varies with position and direction.","Sampled light fields can support changes in viewpoint or computational refocusing when their coverage and resolution are sufficient."]}},"sources":[{"title":"Wikidata item Q593161: light field","url":"https://www.wikidata.org/wiki/Q593161","note":"identity and sense of the item"},{"title":"Wikipedia: Light field","url":"https://en.wikipedia.org/wiki/Light_field","note":"general description of the item"}],"openQuestions":["Does vr.tr.light-field intend the optical radiance concept, the four-dimensional computational-photography convention or a broader electromagnetic meaning?","Which authoritative definition should govern the relationship between light field and plenoptic function in this registry?","Should time, wavelength and polarisation be optional extensions within this entry or relations to neighbouring models?","How should fields in participating or refractive media be represented without implying the free-space four-dimensional reduction applies?","Which task-specific validation criteria should determine acceptable view synthesis, refocusing and geometric inference?"],"resources":{"spec":"/models/things/publications/thing-q593161/spec.json"},"provenance":{"origin":"thing registry research (pass 2)","builtFrom":["models/things/publications/thing-q593161/spec.json"],"providers":["Codex"],"researchStatus":"unreviewed","generatedAt":"2026-09-12T10:58:10Z","builder":"tools/build_cards.py@1.0.0"},"completeness":{"sections":{"classifiers":"filled","whatItIs":"filled","purpose":"filled","distinguishingFeatures":"filled","structure":"filled","agentConduct":"filled","ethics":"filled","owners":"filled","relations":"filled","interaction.identity":"filled","interaction.properties":"not-applicable","interaction.recognition":"not-applicable","interaction.capabilities":"filled","interaction.hazards":"filled","interaction.interfaces":"filled","interaction.context":"filled","sources":"filled"},"notes":{"_gate":"Published through the thing publication gate 1.0 on 2026-10-07T10:10:31+00:00: completeness 1.00; sense: Wikidata description; 2 live sources; review by codex: pass","interaction.properties":"Plane XCT: no invented physical properties.","interaction.recognition":"A light field is a mathematical description whose identity cannot be established from visual appearance alone."},"score":1.0}}