skip to main content
10.1145/3610548.3618241acmconferencesArticle/Chapter ViewAbstractPublication Pagessiggraph-asiaConference Proceedingsconference-collections
research-article

A Micrograin BSDF Model for the Rendering of Porous Layers

Published: 11 December 2023 Publication History

Abstract

We introduce a new BSDF model for the rendering of porous layers, as found on surfaces covered by dust, rust, dirt, or sprayed paint. Our approach is based on a distribution of elliptical opaque micrograins, extending the Trowbridge-Reitz (GGX) distribution [Trowbridge and Reitz 1975; Walter et al. 2007] to handle pores (i.e., spaces between micrograins). We use distance field statistics to derive the corresponding Normal Distribution Function (NDF) and Geometric Attenuation Factor (GAF), as well as a view- and light-dependent filling factor to blend between the porous and base layers. All the derived terms show excellent agreement when compared against numerical simulations.
Our approach has several advantages compared to previous work [d’Eon et al. 2023; Merillou et al. 2000; Wang et al. 2022]. First, it decouples structural and reflectance parameters, leading to an analytical single-scattering formula regardless of the choice of micrograin reflectance. Second, we show that the classical texture maps (albedo, roughness, etc) used for spatially-varying material parameters are easily retargeted to work with our model. Finally, the BRDF parameters of our model behave linearly, granting direct multi-scale rendering using classical mip mapping.

Supplemental Material

ZIP File
In this supplemental archive, we provide a number of additional derivations and results for our micrograin BSDF model. # Mathematical derivations (supplemental.pdf) In this document, we provide all the mathematical details used to derive formula in the paper, additional validations and comparisons. # Additional results (param-variations.pdf) In this document, we explore the appearance of homogeneous versions of our material model along parameter dimensions. # ShaderToy programs We have put three (anonymized) ShaderToy programs online, one for each of the three scenes described in the paper - Mossy stones : https://www.shadertoy.com/view/cty3Dt - Dusty wood : https://www.shadertoy.com/view/DlG3Dt - Graffiti : https://www.shadertoy.com/view/cly3Dt We encourage readers to try the shaders for themselves (in fullscreen), and inspect the corresponding GLSL code (in the common tab for the material source code, and in the main tab for scene management). Controls are the same for all three shaders, as described in their descriptions. In the case of the Mossy Stone scene, the screen is split in two to compare between linear blending and our weighting, as in Figure 14 of the paper. We also provide video captures of all three shaders in action.
ZIP File
In this supplemental archive, we provide a number of additional derivations and results for our micrograin BSDF model. In supplemental.pdf, we provide all the mathematical details used to derive formula in the paper, additional validations and comparisons. In param-variations.pdf, we explore the appearance of homogeneous versions of our material model along parameter dimensions. We have put three ShaderToy programs online, one for each of the three scenes described in the paper - Mossy stones : https://www.shadertoy.com/view/cty3Dt - Dusty wood : https://www.shadertoy.com/view/DlG3Dt - Graffiti : https://www.shadertoy.com/view/cly3Dt We also provide video captures of all three shaders in action.

References

[1]
M. Ashikhmin, S. Premoze, and P. Shirley. 2000. A microfacet-based BRDF generator. In Proceedings of the 27th Annual Conference on Computer Graphics and Interactive Techniques, SIGGRAPH 2000, New Orleans, LA, USA, July 23-28, 2000. ACM, 65–74.
[2]
A. Atanasov, V. Koylazov, R. Dimov, and A. Wilkie. 2022. Microsurface Transformations. Computer Graphics Forum 41, 4 (2022), 105–116. https://doi.org/10.1111/cgf.14590 arXiv:https://onlinelibrary.wiley.com/doi/pdf/10.1111/cgf.14590
[3]
P. Barla, R. Pacanowski, and P. Vangorp. 2018. A Composite BRDF Model for Hazy Gloss. Computer Graphics Forum 37, 4 (2018), 55–66. https://doi.org/10.1111/cgf.13475 arXiv:https://onlinelibrary.wiley.com/doi/pdf/10.1111/cgf.13475
[4]
Benedikt Bitterli and Eugene d’Eon. 2022. A Position-Free Path Integral for Homogeneous Slabs and Multiple Scattering on Smith Microfacets. Computer Graphics Forum 41, 4 (2022), 93–104. https://doi.org/10.1111/cgf.14589 arXiv:https://onlinelibrary.wiley.com/doi/pdf/10.1111/cgf.14589
[5]
R. L. Cook and K. E. Torrance. 1982. A Reflectance Model for Computer Graphics. In ACM SIGGRAPH proceedings.
[6]
Herbert A David and Haikady N Nagaraja. 2004. Order statistics. John Wiley & Sons.
[7]
Eugene d’Eon. 2021. An analytic BRDF for materials with spherical Lambertian scatterers. Computer Graphics Forum 40, 4 (2021), 153–161. https://doi.org/10.1111/cgf.14348 arXiv:https://onlinelibrary.wiley.com/doi/pdf/10.1111/cgf.14348
[8]
Eugene d’Eon, Benedikt Bitterli, Andrea Weidlich, and Tizian Zeltner. 2023. Microfacet theory for non-uniform heightfields. In SIGGRAPH 2023 Conference Papers (Los Angeles, CA, USA). Association for Computing Machinery, New York, NY, USA, 10 pages. https://doi.org/10.1145/3588432.3591486
[9]
Jonathan Dupuy, Eric Heitz, and Eugene d’Eon. 2016. Additional Progress towards the Unification of Microfacet and Microflake Theories. In Proceedings of the Eurographics Symposium on Rendering: Experimental Ideas & Implementations (Dublin, Ireland) (EGSR ’16). Eurographics Association, Goslar, DEU, 55–63.
[10]
Alejandro Conty Estevez and Christopher Kulla. 2017. Production Friendly Microfacet Sheen BRDF. ACM SIGGRAPH 2017 (2017).
[11]
Bruce Hapke. 2012. Theory of Reflectance and Emittance Spectroscopy (2 ed.). Cambridge University Press. https://doi.org/10.1017/CBO9781139025683
[12]
E. Heitz. 2014. Understanding the Masking-Shadowing Function in Microfacet-Based BRDFs. Journal of Computer Graphics Techniques 3, 2 (June 2014).
[13]
Eric Heitz. 2018. Sampling the GGX Distribution of Visible Normals. Journal of Computer Graphics Techniques (JCGT) 7, 4 (30 November 2018), 1–13. http://jcgt.org/published/0007/04/01/
[14]
Eric Heitz and Jonathan Dupuy. 2015. Implementing a Simple Anisotropic Rough Diffuse Material with Stochastic Evaluation. Technical Report.
[15]
Eric Heitz, Johannes Hanika, Eugene d’Eon, and Carsten Dachsbacher. 2016. Multiple-Scattering Microfacet BSDFs with the Smith Model. ACM Trans. Graph. 35, 4, Article 58 (jul 2016), 14 pages. https://doi.org/10.1145/2897824.2925943
[16]
Wenzel Jakob, Sébastien Speierer, Nicolas Roussel, Merlin Nimier-David, Delio Vicini, Tizian Zeltner, Baptiste Nicolet, Miguel Crespo, Vincent Leroy, and Ziyi Zhang. 2022. Mitsuba 3 renderer. https://mitsuba-renderer.org.
[17]
Joo Ho Lee, Adrian Jarabo, Daniel S. Jeon, Diego Gutierrez, and Min H. Kim. 2018. Practical Multiple Scattering for Rough Surfaces. ACM Trans. Graph. 37, 6, Article 275 (dec 2018), 12 pages. https://doi.org/10.1145/3272127.3275016
[18]
S. Merillou, J.-M. Dischler, and D. Ghazanfarpour. 2000. A BRDF postprocess to integrate porosity on rendered surfaces. IEEE Transactions on Visualization and Computer Graphics 6, 4 (2000), 306–318. https://doi.org/10.1109/2945.895876
[19]
Thomas Müller, Marios Papas, Markus Gross, Wojciech Jarosz, and Jan Novák. 2016. Efficient Rendering of Heterogeneous Polydisperse Granular Media. ACM Transactions on Graphics (Proceedings of SIGGRAPH Asia) 35, 6 (Dec. 2016), 168:1–168:14. https://doi.org/10/f9cm65
[20]
M. Oren and S. K. Nayar. 1994. Generalization of Lambert’s Reflectance Model. In ACM SIGGRAPH proceedings.
[21]
B. Smith. 1967. Geometrical shadowing of a random rough surface. IEEE Transactions on Antennas and Propagation 15, 5 (September 1967), 668–671.
[22]
K. E. Torrance and E. M. Sparrow. 1967. Theory for Off-Specular Reflection From Roughened Surfaces*. J. Opt. Soc. Am. 57, 9 (Sep 1967), 1105–1114. https://doi.org/10.1364/JOSA.57.001105
[23]
T. S. Trowbridge and K. P. Reitz. 1975. Average irregularity representation of a rough surface for ray reflection. J. Opt. Soc. Am. 65, 5 (May 1975), 531–536. https://doi.org/10.1364/JOSA.65.000531
[24]
B. Walter, S. R. Marschner, H. Li, and K. E. Torrance. 2007. Microfacet Models for Refraction Through Rough Surfaces. In Computer Graphics Forum, EGSR proceedings.
[25]
Beibei Wang, Wenhua Jin, Miloš Hašan, and Ling-Qi Yan. 2022. SpongeCake: A Layered Microflake Surface Appearance Model. ACM Trans. Graph. 42, 1, Article 8 (sep 2022), 16 pages. https://doi.org/10.1145/3546940
[26]
Feng Xie and Pat Hanrahan. 2018. Multiple Scattering from Distributions of Specular V-Grooves. ACM Trans. Graph. 37, 6, Article 276 (dec 2018), 14 pages. https://doi.org/10.1145/3272127.3275078
[27]
Tizian Zeltner, Brent Burley, and Matt Jen-Yuan Chiang. 2022. Practical Multiple-Scattering Sheen Using Linearly Transformed Cosines. In ACM SIGGRAPH 2022 Talks (Vancouver, BC, Canada) (SIGGRAPH ’22). Association for Computing Machinery, New York, NY, USA, Article 7, 2 pages. https://doi.org/10.1145/3532836.3536240

Cited By

View all

Index Terms

  1. A Micrograin BSDF Model for the Rendering of Porous Layers

    Recommendations

    Comments

    Information & Contributors

    Information

    Published In

    cover image ACM Conferences
    SA '23: SIGGRAPH Asia 2023 Conference Papers
    December 2023
    1113 pages
    ISBN:9798400703157
    DOI:10.1145/3610548
    Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. Copyrights for components of this work owned by others than the author(s) must be honored. Abstracting with credit is permitted. To copy otherwise, or republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. Request permissions from [email protected].

    Sponsors

    Publisher

    Association for Computing Machinery

    New York, NY, United States

    Publication History

    Published: 11 December 2023

    Permissions

    Request permissions for this article.

    Check for updates

    Author Tags

    1. BRDF
    2. BSDF
    3. anfractuosity
    4. micrograin
    5. porosity

    Qualifiers

    • Research-article
    • Research
    • Refereed limited

    Funding Sources

    • Inria

    Conference

    SA '23
    Sponsor:
    SA '23: SIGGRAPH Asia 2023
    December 12 - 15, 2023
    NSW, Sydney, Australia

    Acceptance Rates

    Overall Acceptance Rate 178 of 869 submissions, 20%

    Contributors

    Other Metrics

    Bibliometrics & Citations

    Bibliometrics

    Article Metrics

    • Downloads (Last 12 months)176
    • Downloads (Last 6 weeks)15
    Reflects downloads up to 23 Dec 2024

    Other Metrics

    Citations

    Cited By

    View all

    View Options

    Login options

    View options

    PDF

    View or Download as a PDF file.

    PDF

    eReader

    View online with eReader.

    eReader

    HTML Format

    View this article in HTML Format.

    HTML Format

    Media

    Figures

    Other

    Tables

    Share

    Share

    Share this Publication link

    Share on social media