| Title: |
Importance Sampling of the Micrograin Visible NDF |
| Authors: |
Lucas, Simon; Pacanowski, Romain; Barla, Pascal |
| Contributors: |
Université de Bordeaux (UB); Melting the frontiers between Light, Shape and Matter (MANAO); Laboratoire Bordelais de Recherche en Informatique (LaBRI); Université de Bordeaux (UB)-École Nationale Supérieure d'Électronique, Informatique et Radiocommunications de Bordeaux (ENSEIRB)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB)-École Nationale Supérieure d'Électronique, Informatique et Radiocommunications de Bordeaux (ENSEIRB)-Centre National de la Recherche Scientifique (CNRS)-Centre Inria de l'Université de Bordeaux; Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria); Université Côte d'Azur (UniCA); GRAPHics and DEsign with hEterogeneous COntent (GRAPHDECO); Centre Inria d'Université Côte d'Azur |
| Source: |
ISSN: 0167-7055. |
| Publisher Information: |
CCSD; Wiley |
| Publication Year: |
2025 |
| Collection: |
HAL Université Côte d'Azur |
| Subject Terms: |
Computing methodologies; Reflectance modeling; [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR] |
| Description: |
International audience ; Importance sampling of visible normal distribution functions (vNDF) is a required ingredient for the efficient rendering of microfacet‐based materials. In this paper, we explain how to sample the vNDF for the micrograin material model [LRPB23], which has been recently improved to handle height‐normal correlations through a new Geometric Attenuation Factor (GAF) [LRPB24], leading to a stronger impact on appearance compared to the earlier Smith approximation. To this end, we make two contributions: we derive analytic expressions for the marginal and conditional cumulative distribution functions (CDFs) of the vNDF; we provide efficient methods for inverting these CDFs based respectively on a 2D lookup table and on the triangle‐cut method [Hei20]. |
| Document Type: |
article in journal/newspaper |
| Language: |
English |
| Relation: |
https://archive.softwareheritage.org/swh:1:dir:f0c680dbe08070550c4a4c26ed605c1d33f349a2;origin=https://github.com/lighttransport/lighttransportequation-orb;visit=swh:1:snp:2d7789895dbccf7cf9399ab71cf0aaec4644064f;anchor=swh:1:rev:b059d592a50e82479f6237ae753ae6841b76fe37 |
| DOI: |
10.1111/cgf.70174 |
| Availability: |
https://hal.science/hal-05295492; https://hal.science/hal-05295492v1/document; https://hal.science/hal-05295492v1/file/egsr2025_author.pdf; https://doi.org/10.1111/cgf.70174 |
| Rights: |
https://about.hal.science/hal-authorisation-v1/ ; info:eu-repo/semantics/OpenAccess |
| Accession Number: |
edsbas.A4D94586 |
| Database: |
BASE |