Practical product importance sampling for direct illumination
(2008) Eurographics 2008 27(2). p.681-690- Abstract
- We present a practical algorithm for sampling the product of environment map lighting and surface reflectance.
Our method builds on wavelet-based importance sampling, but has a number of important advantages over previous methods. Most importantly, we avoid using precomputed reflectance functions by sampling the BRDF on-the-fly. Hence, all types of materials can be handled, including anisotropic and spatially varying BRDFs, as well
as procedural shaders. This also opens up for using very high resolution, uncompressed, environment maps. Our
results show that this gives a significant reduction of variance compared to using lower resolution approximations. In addition, we study the wavelet product, and present a... (More) - We present a practical algorithm for sampling the product of environment map lighting and surface reflectance.
Our method builds on wavelet-based importance sampling, but has a number of important advantages over previous methods. Most importantly, we avoid using precomputed reflectance functions by sampling the BRDF on-the-fly. Hence, all types of materials can be handled, including anisotropic and spatially varying BRDFs, as well
as procedural shaders. This also opens up for using very high resolution, uncompressed, environment maps. Our
results show that this gives a significant reduction of variance compared to using lower resolution approximations. In addition, we study the wavelet product, and present a faster algorithm geared for sampling purposes.
For our application, the computations are reduced to a simple quadtree-based multiplication. We build the BRDF
approximation and evaluate the product in a single tree traversal, which makes the algorithm both faster and more
flexible than previous methods. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/1152604
- author
- Clarberg, Petrik LU and Akenine-Möller, Tomas LU
- organization
- publishing date
- 2008
- type
- Chapter in Book/Report/Conference proceeding
- publication status
- published
- subject
- keywords
- Ray tracing, Photo-realistic rendering, Computer graphics, Importance sampling
- host publication
- Computer Graphics Forum
- editor
- Scopigno, Roberto and Gröller, Eduard
- volume
- 27
- issue
- 2
- pages
- 10 pages
- publisher
- Wiley-Blackwell
- conference name
- Eurographics 2008
- conference location
- Crete, Greece
- conference dates
- 2008-04-14
- external identifiers
-
- wos:000255285500058
- scopus:42949083149
- ISSN
- 0167-7055
- 1467-8659
- DOI
- 10.1111/j.1467-8659.2008.01166.x
- language
- English
- LU publication?
- yes
- id
- 8dec139f-a132-4e62-ac82-8acaf9cd5d7b (old id 1152604)
- date added to LUP
- 2016-04-01 12:12:10
- date last changed
- 2025-01-02 09:19:20
@inproceedings{8dec139f-a132-4e62-ac82-8acaf9cd5d7b, abstract = {{We present a practical algorithm for sampling the product of environment map lighting and surface reflectance. <br/><br> Our method builds on wavelet-based importance sampling, but has a number of important advantages over previous methods. Most importantly, we avoid using precomputed reflectance functions by sampling the BRDF on-the-fly. Hence, all types of materials can be handled, including anisotropic and spatially varying BRDFs, as well <br/><br> as procedural shaders. This also opens up for using very high resolution, uncompressed, environment maps. Our <br/><br> results show that this gives a significant reduction of variance compared to using lower resolution approximations. In addition, we study the wavelet product, and present a faster algorithm geared for sampling purposes. <br/><br> For our application, the computations are reduced to a simple quadtree-based multiplication. We build the BRDF <br/><br> approximation and evaluate the product in a single tree traversal, which makes the algorithm both faster and more <br/><br> flexible than previous methods.}}, author = {{Clarberg, Petrik and Akenine-Möller, Tomas}}, booktitle = {{Computer Graphics Forum}}, editor = {{Scopigno, Roberto and Gröller, Eduard}}, issn = {{0167-7055}}, keywords = {{Ray tracing; Photo-realistic rendering; Computer graphics; Importance sampling}}, language = {{eng}}, number = {{2}}, pages = {{681--690}}, publisher = {{Wiley-Blackwell}}, title = {{Practical product importance sampling for direct illumination}}, url = {{http://dx.doi.org/10.1111/j.1467-8659.2008.01166.x}}, doi = {{10.1111/j.1467-8659.2008.01166.x}}, volume = {{27}}, year = {{2008}}, }