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Record W2107541503 · doi:10.1109/iccv.1993.378226

Diffuse shading, visibility fields, and the geometry of ambient light

2002· article· en· W2107541503 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.

Bibliographic record

Venuenot available
Typearticle
Languageen
FieldComputer Science
TopicComputer Graphics and Visualization Techniques
Canadian institutionsMcGill University
Fundersnot available
KeywordsSkyVisibilityShadingOpticsAperture (computer memory)Rendering (computer graphics)Surface (topology)InversePhysicsComputationDiffuse reflectionComputer scienceComputer graphics (images)GeometryMathematicsAlgorithmAstronomy

Abstract

fetched live from OpenAlex

A dominating sky principle is introduced. It states that under diffuse lighting conditions, ambient light has a bimodal structure: the sky is typically much brighter than the ground. The dominating sky principle suggests a general model of image formation under diffuse lighting conditions. The idea behind this model is that the luminous intensity of a surface is determined by the visible region of the diffuse source, or surface visibility function. The model is presented. A novel concept in shading analysis, surface aperture, is discussed. Surface aperture is the solid angle of the visible diffuse source. Although the unit surface normal is a factor under diffuse lighting conditions, in most situations surface aperture dominates. The surface visibility and aperture functions are embedded into visibility and aperture fields defined in the free space above the surfaces. The visibility field is useful because it satisfies simple local constraints. A fast, parallel computation is described for the forward problem of rendering a surface which is illuminated by a diffuse source and for the inverse problem, namely, shape from shading on a cloudy day. The forward and inverse solutions are quite similar. Experimental results are presented.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Theoretical or conceptual · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: none
Teacher disagreement score0.937
Threshold uncertainty score0.155

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.016
GPT teacher head0.252
Teacher spread0.236 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it