--------------------------------------------- # Compression, Interpolation, and Importance Sampling for Polarized BRDF Models: Supplementary Materials Preferred citation (DataCite format): Omer, Khalid Mobarak; Kupinski, Meredith (2022). Compression, Interpolation, and Importance Sampling for Polarized BRDF Models: Supplementary Materials. University of Arizona Research Data Repository. Dataset. https://doi.org/10.25422/azu.data.19127063 Corresponding Author: Khalid Mobarak Omer, University of Arizona Optical Sciences, komer@email.arizona.edu License: CC BY 4.0 (data) MIT (code) DOI: https://doi.org/10.25422/azu.data.19127063 --------------------------------------------- ## Summary Supplementary Materials to the "Compression, Interpolation, and Importance Sampling for Polarized BRDF Models" paper. Included in the ".zip" folder are * The triply degenerate (TD) compressed polarimetric bidirectional reflectance distribution function (pBRDF) dataset in both a 4x2 and 3x3 (as detailed in the paper) for all 25 materials in the [KAIST pBRDF dataset](http://vclab.kaist.ac.kr/siggraph2020/). * Also included are the necessary Mitsuba 2 plug-ins required to render objects using the TD and TD probabilistic model. Preferred citation: Khalid Omer and Meredith Kupinski, "Compression, Interpolation, and Importance Sampling for Polarized BRDF Models," Opt. Express (2022) (In Review) --------------------------------------------- ## Files and Folders Material pBSDFs.zip -"#_Material_mitsuba" (material directory) -"#_Material_inpainted_4x2.pbsdf" - The material TD dataset (4 x 2) using the inpainted database from the KAIST pBRDF dataset. -"#_Material_raw_4x2.pbsdf" - The material TD dataset (4 x 2) using the raw database from the KAIST pBRDF dataset. -"#_Material_inpainted_3x3.pbsdf" - The material TD dataset (3 x 3) using the inpainted database from the KAIST pBRDF dataset. -"#_Material_raw_3x3.pbsdf" - The material TD dataset (3 x 3) using the raw database from the KAIST pBRDF dataset. Mitsuba2 Plug-ins.zip -"mueller.h" - The file containing functions which are required to run the TD pBRDF plug-in. This will replace your existing mueller.h file -"TDMeasuredPolarized.cpp" - Mitsuba 2 pBRDF plug-in to render materials using the TD dataset (deterministic, no polarimetric importance sampling) -"TDProbMeasuredPolarized.cpp" - Mitsuba 2 pBRDF plug-in to render materials using the TD dataset (polarimetric importance sampling) --------------------------------------------- ## Materials & Methods INSTALLATION GUIDE: The source file as well as directions on how to install Mitsuba2 can be found here: https://mitsuba2.readthedocs.io/ Once installed, the two ".cpp" files in the "Mitsuba2 Plug-Ins" folder must be placed into the "mitsuba2/src/bsdfs" folder. Incorporate these files into the "CMakeLists.txt" : Ex. add_plugin(TD_measured_polarized TDMeasuredPolarized.cpp) add_plugin(TDProb_measured_polarized ProbTDMeasuredPolarized.cpp) These two files utilize additional functions required to convert the TD parameters to a Mueller matrix. These can be found in the "mueller.h" file which is included in this folder. Move and replace the existing "mueller.h" located in "mitsuba2/include/mitsuba/render/". Note: Due to phase unwrapping not being an option, these files use the 3x3 form of the pBRDF database. The "mueller.h" file contains the necessary function required to convert the coherency eigenvector to a MM if using a 4x2 database form. We have also included the 4x2 database. ======================================================================================= MATERIAL DATASET: The "Material pBRDFs" folder contains the .pbsdf files required to render different materials. Within each material folder, there are 4 pbsdf files. Two of them corresponding to the "raw" database, where no interpolation is done to fill in unmeasured geometries (raw_4x2 and raw_3x3). The other two have been interpolated to fill in the unmeasured geometries within the database (inpainted_4x2 and inpainted_3x3). Sphere renderings in the paper utilized the inpainted database to ensure the full sphere is rendered. ======================================================================================= TENSOR FORMAT: 4x2 TD Database M: 361 x 91 x 91 x 5 x 4 x 2 (phi_d x theta_d, theta_h, wvls, TD parameter row, TD parameter column) Here, the 4x2 matrix is in the following form: M00 xi0 c01_r c01_i c02_r c02_i c03_r c03_i Here, M00 is the average throughput required to turn the normalized MM to an unnormalized MM, xi0 is the largest eigenvalue of the coherency eigenspectrum, and c01_r/c01_i, c02_r/c02_i/, c03_r.c03_i are the real/imaginary components of the corresponding eigenvector c0 (excluding c00 which is solved in the "mueller.h" script). 3x3 TD Database M: 361 x 91 x 91 x 5 x 3 x 3 (phi_d x theta_d, theta_h, wvls, TD parameter row, TD parameter column) Here, the 4x2 matrix is in the following form: M00 xi0 c00_r c01_r c01_i c02_r c02_i c03_r c03_i All the remaining parameters are the same as the ones used in the KAIST pBRDF database (see their README for additional information: http://vclab.kaist.ac.kr/siggraph2020/pbrdfdataset/README.txt) Here, M00 is the average throughput required to turn the normalized MM to an unnormalized MM, xi0 is the largest eigenvalue of the coherency eigenspectrum, and c00_r, c01_r/c01_i, c02_r/c02_i/, c03_r.c03_i are the real/imaginary components of the corresponding eigenvector c0. ======================================================================================= RELEVANT LINKS: KAIST pBRDF dataset paper: vclab.kaist.ac.kr/siggraph2020/ TD model paper: https://doi.org/10.1364/OE.425295 Mitsuba2 GitHub Repo: https://github.com/mitsuba-renderer/mitsuba2 --------------------------------------------- ## Additional Notes Links: - http://vclab.kaist.ac.kr/siggraph2020/ - https://doi.org/10.1364/OE.425295 - https://github.com/mitsuba-renderer/mitsuba2