% -------------------------------------------------------------------------- % % BIBLIOGRAPHY FOR ADJOINTS AND IMPORTANCE % Part 2: Computer Graphics % % Compiled by Per H. Christensen % per.christensen (at) acm.org % % January 6, 2009 % % This annotated bibliography contains references to articles, % dissertations, and books about the use of importance (defined % as an adjoint of light) in ray tracing and global illumination. % % The entries are divided into six categories: % - Theoretical results in rendering % - "Classic" ray tracing and distribution ray tracing % - Finite element methods % - Monte Carlo methods % - Volume ray tracing and participating media % - Overviews % The entries are sorted chronologically within each category. % % Note that importance is also known as "visual importance", "potential", % "visual potential", "value", or "potential value". % % Many thanks to Philippe Bekaert and Rick Speer who helped point out and % find some of these references. % % I have been unable to find and read a few of the references; those are % marked with "(*)". % % -------------------------------------------------------------------------- % % THEORETICAL RESULTS REGARDING ADJOINTS AND IMPORTANCE IN RENDERING % @INPROCEEDINGS{Pattanaik93a, author = "Sumanta N. Pattanaik", title = "The Mathematical Framework of Adjoint Equations for Illumination Computations", booktitle = "Graphics, Design and Visualization (Proceedings of the International Conference on Computer Graphics, ICCG93)", pages = "123--137", publisher = "North-Holland Publishers", year = 1993, keywords = {global illumination, adjoints, gathering methods, shooting methods}, comments = "Shows that the transport equation for (exitant) radiance is the basis for gathering methods and that the transport equation for (incident) importance is the basis for shooting methods." } @ARTICLE{Pattanaik93b, author = "Sumanta N. Pattanaik and S. P. Mudur", title = "The Potential Equation and Importance in Illumination Computations", journal = "Computer Graphics Forum", volume = 12, number = 2, pages = "131--136", month = Jun, year = 1993, keywords = {global illumination, adjoints, radiosity, radiance, diffuse importance, directional importance}, comments = "Shows that the transport equation for discrete diffuse importance [Smits92] (the adjoint of the discrete radiosity equation) is a special case of the general transport equation for importance (the adjoint of the transport equation for radiance)." } @INPROCEEDINGS{Dutre94a, author = "Philip Dutr\'e and Eric P. Lafortune and Yves D. Willems", title = "A Mathematical Framework for Global Illumination Algorithms", booktitle = "Proceedings of the Winter School of Computer Graphics '94", pages = "75--84", address = "University of West Bohemia, Plzen, Czech Republic", month = Jan, year = 1994, keywords = {global illumination, radiance, importance, adjoints, global reflection distribution function}, comments = "Describes exitant and incident radiance and their transport equations and shows that they are adjoint. Also describes incident and exitant importance and notes that their transport equations are as for radiance. This framework can describe most existing rendering algorithms. Also describes the `global reflection distribution function' (GRDF), a generalization of the BRDF that describes how large a fraction of the radiance from a certain direction to a point makes it to some other point and direction." } @PHDTHESIS{Arvo95, author = "James R. Arvo", title = "Analytic Methods for Simulated Light Transport", school = "Yale University", address = "New Haven, Connecticut", month = Dec, year = 1995, keywords = {light transport, direct illumination, global illumination, analytical methods, irradiance Jacobian, spherical triangles, adjoints, radiance, importance}, comments = "Talks about importance-driven global illumination. Shows that the reflection operator is self-adjoint and that the geometry operator is also self-adjoint. Derives the adjoint transport operator. Shows that two-point transport intensity is radiance times a geometric term, and that the rendering equation is equivalent to the transport equation for radiance." } @INPROCEEDINGS{Veach96, author = "Eric Veach", title = "Non-Symmetric Scattering in Light Transport Algorithms", booktitle = "Rendering Techniques '96 (Proceedings of the Seventh Eurographics Workshop on Rendering)", pages = "81--90", publisher = "Springer-Verlag", year = 1996, keywords = {global illumination, non-symmetry, adjoints, refraction, shading normal, normal interpolation, bump map}, comments = "Shows that if the bidirectional scattering distribution function (BSDF) is non-symmetric, importance is transported differently than light. Examples are refraction (because the indices of refraction differ) and the use of interpolated shading normals different from geometric normals." } % % "PURE" RAY TRACING AND DISTRIBUTION RAY TRACING % @MASTERSTHESIS{Fitzhorn82, author = "Patrick A. Fitzhorn", title = "Realistic Image Synthesis: A Time Complexity Analysis of Ray Tracing", school = "Colorado State University", address = "Fort Collins, Colorado", year = 1982, keywords = {ray tracing, ray tree pruning}, comments = "Uses importance to avoid tracing rays with insignificant contribution to the image. Referenced in [Speer85]." } @ARTICLE{Hall83, author = "Roy A. Hall and Donald P. Greenberg", title = "A Testbed for Realistic Image Synthesis", journal = "IEEE Computer Graphics and Applications", volume = 3, number = 8, pages = "10--20", month = Nov, year = 1983, keywords = {ray tracing, efficiency, ray tree pruning}, comments = "Describes the use of importance (although it wasn't called that) to avoid tracing rays with insignificant contribution to the image." } @INPROCEEDINGS{Cook84, author = "Robert L. Cook and Thomas Porter and Loren Carpenter", title = "Distributed Ray Tracing", booktitle = "Computer Graphics (SIGGRAPH 84 Conference Proceedings)", pages = "137--145", organization = "ACM", month = Jul, year = 1984, keywords = {distribution ray tracing, Monte Carlo, stochastic sampling, glossy reflection, glossy refraction (translucency), soft shadows (penumbras), depth of field, motion blur}, comments = "Introduces distribution ray tracing, a Monte Carlo method to compute glossy reflection and refraction, soft shadows, depth of field, and motion blur by distributing the ray origins, directions, and time. Points out that the number of new rays to be traced at glossy reflection and refraction should be proportional to the importance (contribution). (Does not mention that the number of rays to be used for soft shadow calculation should also depend on the importance.)" } @INPROCEEDINGS{Heckbert84, author = "Paul S. Heckbert and Pat Hanrahan", title = "Beam tracing polygonal objects", booktitle = "Computer Graphics (SIGGRAPH 84 Conference Proceedings)", pages = "119--127", organization = "ACM", month = Jul, year = 1984, keywords = {beam tracing, polygonal scenes}, comments = "Uses importance (called 'threshold of insignificance') to terminate beams of rays." } @INPROCEEDINGS{Speer85, author = "L. Richard Speer and Tony D. DeRose and Brian A. Barsky", title = "A theoretical and empirical analysis of coherent ray-tracing", booktitle = "Proceedings of Graphics Interface '85", pages = "1--8", year = 1985, keywords = {coherent ray tracing}, comments = "Uses importance (called 'attenuated intensity coefficient') to terminate beams of rays." } @ARTICLE{Cleary86, author = "J. G. Cleary and B. M. Wyvill and G. M. Birtwistle and R. Vatti", title = "Multiprocessor ray tracing", journal = "Computer Graphics Forum", volume = 5, number = 1, pages = "3--12", month = Mar, year = 1986, keywords = {ray tracing, parallel execution}, comments = "Stores importance with each ray? Referenced in [Pharr97].", note = "(*)" } @INPROCEEDINGS{Ward88, author = "Gregory J. Ward and Francis M. Rubinstein and Robert D. Clear", title = "A Ray Tracing Solution for Diffuse Interreflection", booktitle = "Computer Graphics (SIGGRAPH 88 Conference Proceedings)", pages = "85--92", organization = "ACM", month = Aug, year = 1988, keywords = {distribution ray tracing, Monte Carlo, diffuse reflection}, comments = "Uses importance to reduce the number of rays in distribution ray tracing. Sets the number of rays proportional to 1/importance^2." } @INPROCEEDINGS{Arvo90, author = "James R. Arvo and David B. Kirk", title = "Particle Transport and Image Synthesis", booktitle = "Computer Graphics (SIGGRAPH 90 Conference Proceedings)", pages = "63--66", organization = "ACM", month = Aug, year = 1990, keywords = {distribution ray tracing, Monte Carlo, particle transport, rendering equation, splitting, Russian roulette}, comments = "Points out that instead of simply not tracing unimportant rays (truncating the ray tree), Russian roulette should be used in order to avoid bias." } @INPROCEEDINGS{Ward91, author = "Gregory J. Ward", title = "Adaptive Shadow Testing for Ray Tracing", booktitle = "Proceedings of the Second Eurographics Workshop on Rendering", pages = "11--20", organization = "Eurographics", year = 1991, month = May, keywords = {ray tracing, efficiency, direct illumination, visibility, many lights}, comments = "Sorts the light sources according to potential illumination at each point. Only checks visibility for the potentially brightest light sources at each point, and uses statistical estimates for the visibility of other light sources. Mentions that the tolerance can be increased for secondary rays with low contribution (importance)." } @INPROCEEDINGS{Heirich96, author = "Alan Heirich and James Arvo", title = "Scalable Photorealistic Rendering of Complex Scenes", booktitle = "Proceedings of the First Eurographics Workshop on Parallel Graphics and Visualization", year = 1996, keywords = {global illumination, Monte Carlo, general reflection, distribution ray tracing, complex scenes, parallel execution}, comments = "Parallel implementation of distribution ray tracing. Uses importance to keep track of the contribution of each ray. Defines a ray as (origin, direction, RGB importance)." } @INPROCEEDINGS{Pharr97, author = "Matt Pharr and Craig Kolb and Reid Gershbein and Pat Hanrahan", title = "Rendering Complex Scenes with Memory-Coherent Ray Tracing", booktitle = "Computer Graphics (SIGGRAPH 97 Conference Proceedings)", pages = "101--108", organization = "ACM", month = Aug, year = 1997, keywords = {path tracing, Monte Carlo, ray reordering, Russian roulette}, comments = "Stores the importance and destination pixel for with each unshot ray. This makes it possible to pool the rays and shoot them out of order (to improve geometry cache coherency). Uses Russian roulette to terminate rays." } @BOOK{Larson98, author = "Greg {Ward Larson} and Rob Shakespeare", title = "Rendering with Radiance: The Art and Science of Lighting Visualization", publisher = "Morgan Kaufmann Publishers", year = 1998, keywords = {global illumination, Monte Carlo, general reflection, distribution ray tracing}, comments = "Excellent book on global illumination and Ward's Radiance programs. Page 551: the number of rays in a distribution ray tracing is set to 1/importance (different than [Ward88]). Also on page 551: a distribution ray tracing result can only be used for interpolation if it was originally calculated with an importance (and accuracy) at least as high as the result we're looking for." } @ARTICLE{Christensen99, author = "Per H. Christensen", title = "Importance for Ray Tracing", journal = "Ray Tracing News", volume = 12, number = 2, organization = "ACM", month = Dec, year = 1999, note = "(www.acm.org/tog/resources/RTNews/html/rtnv12n2.html)", keywords = {ray tracing, efficiency, direct illumination, visibility, area lights, many lights, glossy reflection, procedural textures, bump maps, shading normals, level-of-detail, participating media, ray marching}, comments = "Describes some of the many potential uses of importance to speed up ray tracing. Asks the question why importance is not more widely used in commercial and non-commercial ray tracers." } @INPROCEEDINGS{Morley06, author = "R. Keith Morley and Solomon Boulos and Jared Johnson and David Edwards and Peter Shirley and Michael Ashikhmin and Simon Premoze", title = "Image Synthesis using Adjoint Photons", booktitle = "Proceedings of Graphics Interface 2006", pages = "179-186", year = 2006, keywords = {ray tracing, backwards ray tracing, adjoints, participating media}, comments = "Traces adjoint photons. Brute-force approach. Describes the difference between adjoint photons and importance particles (importons)." } % % FINITE ELEMENT METHODS FOR GLOBAL ILLUMINATION % @INPROCEEDINGS{Smits92, author = "Brian E. Smits and James R. Arvo and David H. Salesin", title = "An Importance-Driven Radiosity Algorithm", booktitle = "Computer Graphics (SIGGRAPH 92 Conference Proceedings)", pages = "273--282", organization = "ACM", month = Jul, year = 1992, keywords = {global illumination, finite elements, diffuse reflection, hierarchical radiosity, power importance, adjoints}, comments = "Seminal paper introducing importance to computer graphics. Uses importance for efficient simulation of view-dependent hierarchical radiosity." } @PHDTHESIS{Aupperle93a, author = "Larry Aupperle", title = "Hierarchical Algorithms for Illumination", school = "Department of Computer Science, Princeton University", address = "Princeton, New Jersey", month = Nov, year = 1993, keywords = {global illumination, finite elements, diffuse reflection, glossy reflection, hierarchical radiosity, radiance, importance, three-point transport, hierarchical representation, adaptive refinement}, comments = "Describes hierarchical algorithms for finite element diffuse global illumination (radiosity) and glossy global illumination. Uses importance for the finite element glossy global illumination method. Radiance and and its adjoint, importance, are represented in finite element bases. Refinement is based on estimated transport error, radiance, and importance." } @INPROCEEDINGS{Aupperle93b, author = "Larry Aupperle and Pat Hanrahan", title = "Importance and Discrete Three Point Transport", booktitle = "Proceedings of the Fourth Eurographics Workshop on Rendering", pages = "85--94", organization = "Eurographics", month = Jun, year = 1993, keywords = {global illumination, finite elements, glossy reflection, radiance, two-point importance, three-point transport, hierarchical representation, adaptive refinement}, comments = "Uses importance for a finite element glossy global illumination method where the elements represent radiance and its adjoint, importance. Since all treatment is discrete, the adjoint of the form factor matrix is simply the transposed matrix. Refinement is based on estimated transport error, radiance, and importance." } @INPROCEEDINGS{Christensen93, author = "Per H. Christensen and David H. Salesin and Tony D. DeRose", title = "A Continuous Adjoint Formulation for Radiance Transport", booktitle = "Proceedings of the Fourth Eurographics Workshop on Rendering", pages = "95--104", organization = "Eurographics", month = Jun, year = 1993, keywords = {global illumination, finite elements, glossy reflection, radiance, two-point intensity, directional importance, two-point importance, adjoints, continuity, spherical harmonics}, comments = "Showed that adjoints of radiance (under a certain inner product) are transported like two-point intensity and that two-point importance is such an adjoint. Introduced exitant importance, a quantity closely related to two-point importance and transported exactly like exitant radiance. For non-specular reflection, two-point importance has discontinuities while directional importance is continuous. (The term ``directional importance'' was used here also for two-point importance to distinguish from diffuse importance as in [Smits92].)" } @INPROCEEDINGS{Bekaert94, author = "Philippe Bekaert and Yves D. Willems", title = "A Progressive Importance-Driven Rendering Algorithm", booktitle = "Proceedings of the 10th Spring School on Computer Graphics", pages = "58--67", publisher = "Comenius University, Bratislava, Slovakia", month = Jun, year = 1994, keywords = {global illumination, finite elements, glossy reflection, radiance, two-point importance, three-point transport, shooting, progressive refinement}, comments = "Extends progressive radiosity to patch-to-patch basis functions representing radiance. This is similar to [Aupperle93]s extension of hierarchical radiosity to patch-to-patch radiance. This paper uses shooting for both light and importance to get a progressive algorithm, and uses a combination of radiance and importance to decide which basis to function to `shoot' from next. (Does not use importance to control refinement since there is no refinement in progressive radiosity and progressive radiance.)" } @INPROCEEDINGS{Christensen94, author = "Per H. Christensen and Eric J. Stollnitz and David H. Salesin and Tony D. DeRose", title = "Wavelet Radiance", booktitle = "Proceedings of the Fifth Eurographics Workshop on Rendering", pages = "287--302", organization = "Eurographics", month = Jun, year = 1994, keywords = {global illumination, finite elements, glossy reflection, radiance, directional importance, wavelets, adaptive refinement}, comments = "A finite element glossy global illumination method that uses wavelets to represent the four-dimensional radiance and directional importance functions. Uses estimated transport error, radiance, and importance for adaptive refinement." } @PHDTHESIS{Lischinski94a, author = "Dani Lischinski", title = "Accurate and Reliable Algorithms for Global Illumination", school = "Department of Computer Science, Cornell University", address = "Ithaca, New York", month = Aug, year = 1994, keywords = {global illumination, finite elements, glossy reflection, radiance, directional importance, three-point transport, wavelet representation, adaptive refinement, discontinuity meshing}, comments = "Elaborates on [Lischinski94b] and also talks about discontinuity meshing." } @INPROCEEDINGS{Lischinski94b, author = "Dani Lischinski and Brian Smits and Donald P. Greenberg", title = "Bounds and Error Estimates for Radiosity", booktitle = "Computer Graphics (SIGGRAPH 94 Conference Proceedings)", pages = "67--74", organization = "ACM", month = Jul, year = 1994, keywords = {global illumination, finite elements, diffuse reflection, hierarchical radiosity, power importance, error bounds, error estimates, adaptive refinement}, comments = "Presents error bounds for hierarchical radiosity solutions, and uses them for error-driven adaptive refinement. Also uses importance for the refinement criterion." } @INPROCEEDINGS{Schroder94, author = "Peter Schr{\"o}der and Pat Hanrahan", title = "Wavelet Methods for Radiance Computations", booktitle = "Proceedings of the Fifth Eurographics Workshop on Rendering", pages = "303--311", organization = "Eurographics", month = Jun, year = 1994, keywords = {global illumination, finite elements, glossy reflection, radiance, directional importance, three-point transport, wavelet representation, adaptive refinement}, comments = "A finite element method for glossy global illumination. Uses wavelets to represent radiance and importance, and compares different wavelet bases. Uses estimated transport error, radiance, and importance for adaptive refinement of wavelet radiance." } @INPROCEEDINGS{Smits94a, author = "Brian Smits and James Arvo and Donald Greenberg", title = "A Clustering Algorithm for Radiosity in Complex Environments", booktitle = "Computer Graphics (SIGGRAPH 94 Conference Proceedings)", pages = "435--442", organization = "ACM", month = Jul, year = 1994, keywords = {global illumination, finite elements, diffuse reflection, hierarchical radiosity, power importance, clustering, error bounds, adaptive refinement}, comments = "Extends hierarchical radiosity to clusters. Uses importance for refinement in one example." } @PHDTHESIS{Smits94b, author = "Brian E. Smits", title = "Efficient Hierarchical Radiosity in Complex Environments", school = "Program of Computer Graphics, Cornell University", address = "Ithaca, New York", month = Aug, year = 1994, keywords = {global illumination, finite elements, diffuse reflection, hierarchical radiosity, incident power importance, adjoints, clustering}, comments = "Extended version of [Smits92] and [Smits94a]." } @INPROCEEDINGS{Bekaert95, author = "Philippe Bekaert and Yves D. Willems", title = "Importance-Driven Progressive Refinement Radiosity", booktitle = "Rendering Techniques '95 (Proceedings of the Sixth Eurographics Workshop on Rendering)", pages = "316--325", publisher = "Springer-Verlag", year = 1995, keywords = {global illumination, finite elements, diffuse reflection, progressive radiosity, diffuse importance, shooting, progressive refinement}, comments = "Extends progressive refinement radiosity to use importance. Radiosity and importance are propagated in alternating steps. In traditional progressive radiosity, the patch with the highest unshot power is selected first, but here the patch with the highest importance times unshot radiosity is selected. The method also allows incrementally changing view points." } @PHDTHESIS{Christensen95, author = "Per H. Christensen", title = "Hierarchical Techniques for Glossy Global Illumination", school = "Department of Computer Science and Engineering, University of Washington", address = "Seattle, Washington", month = Jul, year = 1995, keywords = {global illumination, finite elements, glossy reflection, radiance, directional importance, light transport, importance transport, wavelets, clustering}, comments = "A finite element glossy global illumination method. Shows that the reflection operator is self-adjoint and that the geometry operator is also self-adjoint. Derives the adjoint transport operator. Elaborates on the relationship between light and importance: Kajiya's two-point (transport) intensity and two-point importance are adjoint functions of radiance. Radiance and directional importance are adjoint functions of two-point intensity." } @ARTICLE{Christensen96, author = "Per H. Christensen and Eric J. Stollnitz and David H. Salesin and Tony D. DeRose", title = "Global Illumination of Glossy Environments Using Wavelets and Importance", journal = "ACM Transactions on Graphics", volume = 15, number = 1, pages = "37--71", month = Jan, year = 1996, keywords = {global illumination, finite elements, glossy reflection, radiance, directional importance, wavelets, adaptive refinement}, comments = "Extended version of [Christensen94]. Also contains a more intuitive derivation of the adjoint of radiance." } @INPROCEEDINGS{Neumann96, author = "Attila Neumann and L\'aszl\'o Neumann and Philippe Bekaert and Yves D. Willems and Werner Purgathofer", title = "Importance-Driven Stochastic Ray Radiosity", booktitle = "Rendering Techniques '96 (Proceedings of the Seventh Eurographics Workshop on Rendering)", pages = "111--122", publisher = "Springer-Verlag", year = 1996, keywords = {global illumination, finite elements, diffuse reflection, stochastic (ray) radiosity, diffuse importance, incoming directional importance}, comments = "Uses importance to modulate patch sampling probabilities, thereby reducing variance in the important parts of the scene. Their basic algorithm shoots power and power importance in alternating steps. Their improved algorithm uses the same rays to propagate power and power importance. As a further improvement, they also use directional importance: the hemisphere above each patch is divided into 8 solid angles and the incident importance is stored for each solid angle. Directional importance is used to send more rays in the important directions. They also note that importance directly from the image plane should not be used for refinement." } @BOOK{Stollnitz96, author = "Eric J. Stollnitz and Tony D. DeRose and David H. Salesin", title = "Wavelets for Computer Graphics", publisher = "Morgan Kaufmann Publishers", year = 1996, keywords = {wavelets, image synthesis, global illumination, radiosity, radiance, importance}, comments = "Textbook on wavelets in computer graphics. Subsection 13.4.1 describes importance-driven refinement in hierarchical radiosity methods." } @ARTICLE{Christensen97, author = "Per H. Christensen and Dani Lischinski and Eric J. Stollnitz and David H. Salesin", title = "Clustering for Glossy Global Illumination", journal = "ACM Transactions on Graphics", volume = 16, number = 1, pages = "3--33", month = Jan, year = 1997, keywords = {global illumination, finite elements, glossy reflection, radiance, radiant intensity, directional importance, importance intensity, wavelets, clustering, error bounds, adaptive refinement}, comments = "Extends [Christensen96] to clustering of objects. Introduces ``importance intensity'' from a point similar to radiant intensity." } @INPROCEEDINGS{Dutre97, author = "Philip Dutr\'e and Philippe Bekaert and Frank Suykens and Yves D. Willems", title = "Bidirectional Radiosity", booktitle = "Rendering Techniques '97 (Proceedings of the Eighth Eurographics Workshop on Rendering)", pages = "205--216", publisher = "Springer-Verlag", year = 1997, keywords = {global illumination, finite elements, diffuse reflection, radiosity, diffuse importance, bidirectional transport}, comments = "Radiosity method using importance. All directly visible patches are used one at a time as importance source The method avoids computing any radiosity for unimportant patches. The order of the visible patches is selected depending on their projected screen area. Even though the solutions are computed independently one at a time, much information can be reused since the form factors between patches can be reused and also the approximate radiosity on non-visible patches can be reused. Only the importance has to be reset for each new importance source." } @ARTICLE{Pueyo97, author = "Xavier Pueyo and Dani Tost and Ignacio Martin and Blanca Garcia", title = "Radiosity for Dynamic Environments", journal = "The Journal of Visualization and Computer Animation", volume = 8, number = 4, pages = "221--231", month = Oct, year = 1997, keywords = {global illumination, finite elements, radiosity, importance, dynamic scenes, temporal coherence}, comments = "Presents a radiosity algorithm for dynamic environments but static viewpoint. The computation of the images is based on an importance-driven heuristic approach (the importance is not an adjoint). Radiosity is neither shot to or from unimportant patches; the unimportant patches are only used for occlusion testing. The important patches or objects can be manually tagged in the scene database. Patches that contribute significant radiosity to the visible patches are considered important." } % % MONTE CARLO METHODS FOR GLOBAL ILLUMINATION % @INPROCEEDINGS{Lafortune93, author = "Eric Lafortune and Yves Willems", title = "Bi-directional Path Tracing", booktitle = "Proceedings of CompuGraphics '93", address = {Alvor, Portugal}, pages = "145--153", month = Dec, year = 1993, comments = "Importance is the basis for bidirectional Monte Carlo simulation of global illumination."} @PHDTHESIS{Pattanaik93c, author = "Sumanta N. Pattanaik", title = "Computational Methods for Global Illumination and Visualisation of Complex {3D} Environments", school = "Computer Science Department, Birla Institute of Technology \& Science", address = "Pilani, India", month = Feb, year = 1993, keywords = {global illumination, Monte Carlo, general reflection, participating media, volume scattering, radiance, importance, random walk, particle/photon tracing, adjoints, importance sampling, variance reduction}, comments = "Notes that importance is transported just like light. Shows that the transport equations for radiance and importance are adjoint. Discusses their relationship to shooting and gathering methods. Uses importance to bias random walks towards regions of high importance and insufficient number of particles." } @ARTICLE{Pattanaik93d, author = "Sumanta N. Pattanaik and S. P. Mudur", title = "Efficient Potential Equation Solutions for Global Illumination Computation", journal = "Computers \& Graphics", volume = 17, number = 4, pages = "387--396", publisher = "Pergamon Press", year = 1993, keywords = {global illumination, Monte Carlo, diffuse reflection, random walk, particle/photon tracing, adjoints, radiosity, power, diffuse importance}, comments = "A random walk simulation of diffuse global illumination, also known as `Monte Carlo radiosity'. Uses importance to guide the majority of the random walks to the most important regions: emission and reflection is biased towards important regions (importance sampling). First an initial number of particles/photons are emitted and reflected in an unbiased manner, and statistics are gathered of how large a fraction of the particles/photons emitted/reflected from each patch in the direction of an other patch eventually makes it to the important region. (This fraction is kept in an array of size PxP, where P is the number of patches in scene). Then, in the main simulation, emitting patches are selected with probability proportional to their fraction, which is an approximation of (diffuse incident) importance, and directions for emission or reflection are chosen based on the statistics in the PxP array. Adaptively reduces the region of importance by excluding patches that have already received enough photon particles." } @INPROCEEDINGS{Dutre94b, author = "Philip Dutr\'e and Yves D. Willems", title = "Importance-Driven {Monte Carlo} Light Tracing", booktitle = "Proceedings of the Fifth Eurographics Workshop on Rendering", pages = "185--194", organization = "Eurographics", month = Jun, year = 1994, keywords = {global illumination, Monte Carlo, general reflection, random walk, particle/photon tracing, adjoints, importance sampling}, comments = "A random walk algorithm. Does not divide the scene into patches, but sends particles to pixels in the image plane. Uses importance for particle/photon tracing: particles/photons are emitted from the light sources in directions with high importance, ie. importance is used for importance sampling at the light sources." } @ARTICLE{Lafortune94, author = "Eric P. Lafortune and Yves D. Willems", title = "A Theoretical Framework for Physically Based Rendering", journal = "Computer Graphics Forum", volume = 13, number = 2, pages = "97--107", month = Jun, year = 1994, keywords = {global illumination, Monte Carlo, general reflection, bidirectional path tracing, radiance, importance, adjoints, global reflectance distribution function}, comments = "Explains their previously published bidirectional path tracing algorithm using the framework of the radiance and importance equations. Also introduces the `global reflectance distribution function' (GRDF) which is simply the kernel of the solution operator S = (I-T)^-1." } @INPROCEEDINGS{Veach94, author = "Eric Veach and Leonidas Guibas", title = "Bidirectional Estimators for Light Transport", booktitle = "Proceedings of the Fifth Eurographics Workshop on Rendering", pages = "147--162", organization = "Eurographics", month = Jun, year = 1994, keywords = {global illumination, Monte Carlo, general reflection, bidirectional path tracing, variance reduction, adjoints, radiance, importance}, comments = "Uses importance for bidirectional Monte Carlo simulation of global illumination." } @INPROCEEDINGS{Dutre95, author = "Philip Dutr\'e and Yves D. Willems", title = "Potential-Driven {Monte Carlo} Particle Tracing for Diffuse Environments with Adaptive Probability Density Functions", booktitle = "Rendering Techniques '95 (Proceedings of the Sixth Eurographics Workshop on Rendering)", pages = "306--315", publisher = "Springer-Verlag", year = 1995, keywords = {global illumination, Monte Carlo, diffuse reflection, random walk, particle/photon tracing, adjoints, importance sampling}, comments = "Extends [Dutre94b] to also use importance sampling at surfaces. The surfaces are divided into a mesh to store discretized importance functions (discretized over the hemisphere -- the discretization is refined during solution). These importance functions are used to guide emission and reflection of particles/photons. The mesh is not used directly for the light calculation, but only to store the approximate importance functions. The method assumes diffuse surfaces." } @INPROCEEDINGS{Jensen95, author = "Henrik W. Jensen", title = "Importance Driven Path Tracing using the Photon Map", booktitle = "Rendering Techniques '95 (Proc.\ 6th Eurographics Workshop on Rendering)", pages = "326--335", publisher = "Springer-Verlag", year = 1995, keywords = {global illumination, Monte Carlo, diffuse reflection, random walk, particle/photon tracing, importance sampling}, comments = "Uses photon directions to guide path tracing to the brightest parts of the scene. This is importance sampling and does not use adjoints." } @INPROCEEDINGS{Lafortune95, author = "Eric Lafortune and Yves Willems", title = "A {5D} Tree to Reduce the Variance of Monte Carlo Ray Tracing", booktitle = "Rendering Techniques '95 (Proceedings of the Sixth Eurographics Workshop on Rendering)", pages = "11--20", publisher = "Springer-Verlag", year = 1995, comments = "Uses information about the illumination directions to guide path tracing from the eye. Uses a 5D tree structure of ray origins and directions." } @ARTICLE{Pattanaik95a, author = "Sumanta N. Pattanaik and S. P. Mudur", title = "Adjoint Equations and Random Walks for Illumination Computation", journal = "ACM Transactions on Graphics", volume = 14, number = 1, pages = "77--102", month = Jan, year = 1995, keywords = {global illumination, Monte Carlo, diffuse reflection, random walk, particle/photon tracing, adjoints, radiosity, diffuse importance}, comments = "Extended version of [Pattanaik93c]: a random walk simulation of diffuse global illumination. Uses importance to guide the majority of the random walks to the most important regions (importance sampling). Adaptively reduces the region of importance by excluding patches that have already received enough particles/photons." } % pages = "??", @INPROCEEDINGS{Pattanaik95b, author = "Sumanta N. Pattanaik and Kadi Bouatouch", title = "Interactive Walk-Through using Particle Tracing", booktitle = "Computer Graphics Developments in Virtual Environments (Proceedings of Computer Graphics International '95)", publisher = "Academic Press", year = 1995, keywords = {global illumination, Monte Carlo, random walk, particle/photon tracing, adjoints, importance, illuminating capacity, walk-through}, comments = "Keeps a tally of how many particles/photons emitted from each light source that get reflected (through multiple bounces) into different regions of the scene. During an interactive walk-through of the scene, the emission of particles/photons is biased towards emission from those light sources that contribute most to the illumination of the visible region. This is a cheap estimate of importance (without explicit adjoints) and has the advantage that importance does not have to be explicitly transported." } @INPROCEEDINGS{Bouatouch96, author = "Kadi Bouatouch and Sumanta N. Pattanaik and Eric Zeghers", title = "Computation of Higher Order Illumination with a Non-Deterministic Approach", booktitle = "Computer Graphics Forum (Proceedings of Eurographics '96)", pages = "327--338", publisher = "Blackwell Publishers", month = Aug, year = 1996, keywords = {global illumination, Monte Carlo, diffuse reflection, random walk, photon particle tracing, adjoints, importance, wavelet representation}, comments = "Extends the basic random walk radiosity method by using wavelets for the basis functions to represent radiosity. Talks about adjoints and importance, but does not use importance to speed up the implementation." } @INPROCEEDINGS{Jensen96, author = "Henrik W. Jensen", title = "Global Illumination using Photon Maps", booktitle = "Rendering Techniques '96 (Proceedings of the Seventh Eurographics Workshop on Rendering)", pages = "21--30", publisher = "Springer-Verlag", year = 1996, keywords = {global illumination, Monte Carlo, random walk, particle/photon tracing, ray tracing, photon maps}, comments = "Uses the importance of a ray to decide which method to use to compute indirect illumination: lookup in the global photon map (fast, approximate) or distribution ray tracing (slow, accurate). Also suggests the use of an initial importance tracing pass before particle/photon tracing as later implemented in [Peter98]." } @PHDTHESIS{Lafortune96a, author = "Eric P. Lafortune", title = "Mathematical Models and Monte Carlo Algorithms for Physically Based Rendering", school = "Department of Computer Science, Katholieke Universiteit", address = "Leuven, Belgium", month = Feb, year = 1996, keywords = {global illumination, Monte Carlo, bidirectional path tracing, general reflection, radiance, importance}, comments = "Describes transport equations for both light (radiance) and directional importance. Uses these to describe a bidirectional path tracing algorithm." } @PHDTHESIS{Dutre96, author = "Philip Dutr\'e", title = "Mathematical Frameworks and Monte Carlo Algorithms for Global Illumination in Computer Graphics", school = "Department of Computer Science, Katholieke Universiteit", address = "Leuven, Belgium", month = Sep, year = 1996, keywords = {global illumination, Monte Carlo, photon particle tracing, bidirectional path tracing?, general reflection, incident and exitant radiance, incident and exitant importance, adjoints}, comments = "Starts with a thorough and intuitive explanation of incident and exitant radiance and importance. Then describes general Monte Carlo methods for solving integral equations, and describes a photon particle tracing algorithm. Also describes the use of adaptive importance sampling." } @INPROCEEDINGS{Sbert97, author = "Mateu Sbert", title = "Optimal Source Selection in Shooting Random Walk {Monte Carlo} Radiosity", booktitle = "Computer Graphics Forum (Proceedings of Eurographics '97)", pages = "301--308", publisher = "Blackwell Publishers", month = Aug, year = 1997, keywords = {global illumination, Monte Carlo, random walk, radiosity, importance}, comments = "Points out that in order to minimize the variance of the radiosity solution, the number of photon particles to be emitted from each light source should be proportional to the square root of its importance (and not directly proportional to its importance as done by [Pattanaik93a,c,d] and others). The reason is that the variance in the radiosity solution should be inversely proportional to the importance, and the variance is reduced by one over the square root of the number of particles." } @PHDTHESIS{Veach97, author = "Eric Veach", title = "Robust Monte Carlo Methods for Light Transport Simulation", school = "Stanford University", address = "Stanford, California", month = Dec, year = 1997, keywords = {global illumination, Monte Carlo, general reflection, bidirectional path tracing, Metropolis light transport, multiple importance sampling, general reflection, radiance, importance, adjoints}, comments = "Gives detailed descriptions of bidirectional path tracing and the Metropolis light transport algorithm. Also describes how to combine importance sampling with multiple importance functions. Gives a good theoretical overview of radiance and importance transport and adjoints." } @PHDTHESIS{Keller98, author = "Alexander Keller", title = "Quasi-Monte Carlo Methods for Photorealistic Image Synthesis", school = "University of Kaiserslautern", address = "Kaiserslautern, Germany", year = 1998, keywords = {global illumination, general reflection, Monte Carlo, quasi-Monte Carlo, quasi-random walk, photon particle tracing, radiance, radiosity, form factors, wavelets, photon maps, adjoints, importance}, comments = "Describes the theory behind quasi-Monte Carlo sampling and applies it to pixel sampling, radiosity form factor calculation, and solution of the radiance equation (radiosity and particle/photon tracing methods). Describes radiance and importance transport and their adjointness. Does not actually use importance, but suggests the use of an initial importance tracing pass before particle/photon tracing as later implemented in [Peter98]." } @INPROCEEDINGS{Peter98, author = "Ingmar Peter and Georg Pietrek", title = "Importance Driven Construction of Photon Maps", booktitle = "Rendering Techniques '98 (Proceedings of the Ninth Eurographics Workshop on Rendering)", pages = "269--280", publisher = "Springer-Verlag", year = 1998, keywords = {global illumination, Monte Carlo, random walk, importance particle tracing, photon particle tracing, photon map method, importons}, comments = "Traces importance particles (``importons'') from the eye and stores them in an importance map similar to a photon map. The stored importons are used in the photon tracing phase to decide which directions to emit and reflect photons in, thereby focusing the photons in the important parts of the scene." } @INPROCEEDINGS{Szirmay-Kalos98a, author = "L\'aszl\'o Szirmay-Kalos and Bal\'azs Cs\'ebfalvi and Werner Purgathofer", editor = "Vaclav Skala", title = "Importance Driven Quasi-Random Walk Solution of the Rendering Equation", booktitle = "WSCG '98 (Sixth European Conference in Central Europe on Computer Graphics and Visualization)", pages = "379--385", year = 1998, publisher = "University of West Bohemia", address = "Plzen, Czech Republic", comments = "Similar to [Jensen95] (uses photon directions to guide path tracing), but stores the photons on patches instead of in a photon map.", note = "(Also published in Computers and Graphics 23(2):203-212, 1999)" } @INPROCEEDINGS{Szirmay-Kalos98b, author = "L\'aszl\'o Szirmay-Kalos and Werner Purgathofer", editor = "G. Drettakis and N. Max", title = "Global Ray-Bundle Tracing with Hardware Acceleration", booktitle = "Rendering Techniques '98 (Proceedings of the Ninth Eurographics Rendering Workshop '98)", pages = "247--258", publisher = "Springer Verlag", year = 1998, } @PHDTHESIS{Bekaert99, author = "Philippe Bekaert", title = "Hierarchical and Stochastic Algorithms for Radiosity", school = "Katholieke Universiteit", address = "Leuven, Belgium", month = Dec, year = 1999, keywords = {global illumination, diffuse reflections, Monte Carlo, random walk, hierarchical radiosity, power, importance, adjoints}, comments = "Talks about propagation of radiosity and power, and their adjoints. B and J are adjoint functions and P and I are adjoint functions." } @INPROCEEDINGS{Keller00, author = "Alexander Keller and Ingo Wald", title = "Efficient Importance Sampling Techniques for the Photon Map", booktitle = "Proceedings of the Fifth Fall Workshop on Vision, Modeling, and Visualization", pages = "271--279", organization = "IEEE", month = Nov, year = 2000, keywords = {global illumination, Monte Carlo, random walk, importance particle tracing, photon particle tracing, photon map method, importons}, comments = "Improves the importance-driven photon map method [Peter98] by not mixing photons with high and low power. The store probability is determined by importance, and Russian roulette is used for storage: if a photon is stored in a low-importance area, its power is increased. Compared to the non importance-driven photon map method, the same number of photons is traced, but far fewer photons are stored." } %pages = ?? @INPROCEEDINGS{Prikryl00, author = "Jan P\v{r}ikryl and Philippe Bekaert and Werner Purgathofer", title = "Importance-Driven Hierarchical Stochastic Ray Radiosity", booktitle = "Proceedings of the Winter School of Computer Graphics 2000", address = "University of West Bohemia, Plzen, Czech Republic", month = Jan, year = 2000, keywords = {global illumination, Monte Carlo, random walk, Stochastic ray radiosity, hierarchical radiosity, importance}, comments = "Extension of [Neumann96] to use hierarchical radiosity." } @ARTICLE{Sbert00, author = "Mateu Sbert and Alex Brusi and Robert Tobler and Werner Purgathofer", title = "Random Walk Radiosity with Generalized Transition Probabilities", journal = "Graphical Models", volume = 6, number = 2, pages = "56--70", year = "2000", keywords = {global illumination, Monte Carlo, random walk, diffuse reflection, radiosity, diffuse importance, power importance}, comments = "Describes a variation on random walk radiosity with general scattering and absorption probabilities. Elaborates on the relationship between diffuse importance and power importance." } @INPROCEEDINGS{Suykens00, author = "Frank Suykens and Yves D. Willems", title = "Density Control for Photon Maps", booktitle = "Rendering Techniques 2000 (Proceedings of the Eleventh Eurographics Workshop on Rendering)", pages = "11--22", publisher = "Springer-Verlag", year = 2000, keywords = {global illumination, Monte Carlo, random walk, importance particle tracing, photon particle tracing, photon map method, importons}, comments = "Improves the importance-driven photon map method [Peter98] by not mixing photons with high and low power. The store probability is determined by e.g. importance, and if a photon is not stored, its power is distributed among the nearest photons. Compared to the non importance-driven photon map method, the same number of photons is traced, but far fewer photons are stored." } % month = ??", @PHDTHESIS{Szirmay-Kalos00, author = "L\'aszl\'o Szirmay-Kalos", title = "Photorealistic Image Synthesis using Ray-Bundles", type = "Doctoral dissertation", school = "Department of Control Engineering and Information Technology, Technical University of Budapest", address = "Budapest, Hungary", year = 2000, keywords = {global illumination, Monte Carlo, quasi-Monte Carlo, ray bundles, radiosity/radiance?, importance}, } @BOOK{Jensen01a, author = "Henrik W. Jensen", title = "Realistic Image Synthesis Using Photon Mapping", publisher = "A. K. Peters", year = 2001, keywords = {global illumination, Monte Carlo, photon maps, importance}, notes = "Section 11.3, 'Visual Importance'." } @INPROCEEDINGS{Jensen01b, author = "Henrik W. Jensen and Frank Suykens and Per H. Christensen", title = "A Practical Guide to Global Illumination Using Photon Mapping", booktitle = "{SIGGRAPH} 2001 Course Notes \# 38", publisher = "ACM", month = Aug, year = 2001, keywords = {global illumination, Monte Carlo, photon maps, importance} } @INPROCEEDINGS{Benthin03, author = "Carsten Benthin and Ingo Wald and Philipp Slusallek", title = "A Scalable Approach to Interactive Global Illumination", booktitle = "Computer Graphics Forum (Proceedings of Eurographics 2003)", publisher = "Blackwell Publishers", month = Sep, year = 2003, keywords = {Real-time global illumination, Monte Carlo, instant radiance, importance?} } @ARTICLE{Hasan06, author = "Milo\v{s} Ha\v{s}an and Fabio Pellacini and Kavita Bala", title = "Direct-to-Indirect Transfer for Cinematic Relighting", journal = "ACM Transactions on Graphics (Proceedings of SIGGRAPH 2006)", volume = 25, number = 3, pages = "1089--1097", month = Jul, year = 2006, keywords = {Precomputed global illumination, wavelets, interactive relighting}, comments = "Shoots photons (importons) from view samples to estimate importance." } @ARTICLE{Lehtinen08, author = "Jaakko Lehtinen and Matthias Zwicker and Emmanuel Turquin and Janne Kontkanen and Fr{\'e}do Durand and Fran\c{c}ois X. Sillion and Timo Aila" title = "A meshless hierarchical representation for light transport" journal = "ACM Transactions on Graphics (Proceedings of SIGGRAPH 2008)", volume = 27, number = 3, month = Aug, year = 2008, pages = "??", keywords = {}, comments = "Shoots photons (importons) from view point to establish which objects are entirely inside other objects." } % % VOLUME RAY TRACING AND PARTICIPATING MEDIA % @ARTICLE{Levoy90, author = "Marc Levoy", title = "Efficient Ray Tracing of Volume Data", journal = "ACM Transactions on Graphics", volume = 9, number = 3, pages = "245--261", month = Jul, year = 1990, keywords = {volume ray tracing, opacity, ray termination}, comments = "Introduces termination of front-to-back volume rays when the the accumulated opacity is sufficiently high, and their remaining importance therefore is low. Similar to [Hall83]'s termination of rays when importance (weight) is low." } @INPROCEEDINGS{Danskin92, author = "John Danskin and Pat Hanrahan", title = "Fast Algorithms for Volume Ray Tracing", booktitle = "Computer Graphics (Proceedings of the 1992 Workshop on Volume Visualization)", pages = "91--98", organization = "ACM", year = 1992, keywords = {volume ray tracing, opacity, adaptive step length, Russian roulette ray termination}, comments = "Gradually takes fewer samples and reduce calculation precision as a ray accumulates opacity in front-to-back ray tracing. (Credits Larry Aupperle with the idea.) Uses Russian roulette for termination of rays (as [Arvo90] for regular ray tracing). importance for refinement in one example." } @INPROCEEDINGS{Lafortune96b, author = "Eric P. Lafortune and Yves D. Willems", title = "Rendering Participating Media with Bidirectional Path Tracing", booktitle = "Rendering Techniques '96 (Proceedings of the Seventh Eurographics Workshop on Rendering)", pages = "91--100", publisher = "Springer-Verlag", year = 1996, keywords = {global illumination, Monte Carlo, bidirectional path tracing, participating media}, comments = "Extends the bidirectional path tracing method to handle participating media. Does not mention importance directly, but the entire framework of bidirectional path tracing relies heavily on importance (as described in [Lafortune96a])." } @ARTICLE{Jarosz08, author = "Wojciech Jarosz and Matthias Zwicker and Henrik W. Jensen", title = "The Beam Radiance Estimate for Volumetric Photon Mapping", journal = "Computer Graphics Forum (Proceedings of Eurographics 2008)", volume = 27, number = 2, pages = "??", month = April, year = 2008, keywords = {Volume rendering, photon mapping, radiance estimate}, comments = "Uses the importance function to derive general radiance estimates and a beam radiance estimate for volume rendering." } % % OVERVIEWS % @BOOK{Cohen93, author = "Michael F. Cohen and John R. Wallace", title = "Radiosity and Realistic Image Synthesis", publisher = "Academic Press", year = 1993, keywords = {global illumination, radiosity, power importance}, comments = "Textbook about global illumination and radiosity. Sections 7.7 and 7.8 describe the use of power importance to speed up view-dependent radiosity computation." } @BOOK{Sillion94, author = "Fran\c{c}ois X. Sillion and Claude Puech", title = "Radiosity and Global Illumination", publisher = "Morgan Kaufmann Publishers", year = 1994, keywords = {global illumination, radiosity, power importance, adjoints}, comments = "Textbook on global illumination and radiosity. Section 4.5 describes the use of diffuse importance for importance-driven refinement of hierarchical radiosity." } @BOOK{Glassner95, author = "Andrew S. Glassner", title = "Principles of Digital Image Synthesis", publisher = "Morgan Kaufmann Publishers", year = 1995, keywords = {image synthesis, global illumination, adjoints, radiosity, radiance, importance}, comments = "Textbook on image synthesis including global illumination. Section 16.9 describes Monte Carlo estimation including the use of importance (in subsection 16.9.3). Section 18.6 describes hierarchical radiosity including importance-driven refinement (in subsection 18.6.3)." } @BOOK{Dutre03, author = "Philip Dutr\'e and Philippe Bekaert and Kavita Bala", title = "Advanced Global Illumination", publisher = "A.~K.~Peters", year = 2003, keywords = {overview, global illumination, finite elements, Monte Carlo, bidirectional path tracing, participating media}, comments = "Overview of most global illumination methods. Describes incident and exitant importance in section 4.2, adjoints in section 4.3, and uses them in many places throughout the book." } @ARTICLE{Christensen03, author = "Per H. Christensen", title = "Adjoints and Importance in Rendering: an Overview", journal = "IEEE Transactions on Visualization and Computer Graphics", volume = 9, number = 3, pages = "329--340", publisher = "IEEE", month = jul, year = 2003 } @BOOK{Pharr04, author = "Matt Pharr and Greg Humphreys", title = "Physically-Based Rendering: From Theory to Implementation", publisher = "Morgan Kaufmann Publishers", year = 2004, note = "(To appear)", keywords = {global illumination, Monte Carlo, path tracing, distribution ray tracing, photon maps, importance}, comments = "Section 16.2.7, 'The measurement equation and importance'." } % % MISC % % pages = ?? @INPROCEEDINGS{Xu01, author = "Q. Xu and J. Sun and Z. Wei and Y. Shu and S. Messelodi and J. Cai", title = "Zero Variance Importance Sampling Driven Potential Tracing for Global Illumination", booktitle = "Proceedings of the Winter School of Computer Graphics 2001", month = Feb, year = 2001, note = "(*) Available from wcsg.zcu.cz/wcsg2001 ?", keywords = {??}, }