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24
Incoming FirstShot for NonDiffuse Global Illumination
 In Spring Conference on Computer Graphics, Budmerice
, 2000
"... This paper presents a method that can replace the small and medium size lightsources by their effect in nondiffuse global illumination algorithms. Incoming firstshot is a generalization of a preprocessing technique called the firstshot that was developed for speeding up global diffuse radiosity a ..."
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Cited by 11 (8 self)
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This paper presents a method that can replace the small and medium size lightsources by their effect in nondiffuse global illumination algorithms. Incoming firstshot is a generalization of a preprocessing technique called the firstshot that was developed for speeding up global diffuse radiosity algorithms. Alternatively, it can also be approached as a generalization of the directlightsource computation involved in gathering type methods. In order to reduce the prohibitive memory requirements of the original firstshot when it is applied to nondiffuse scenes in a direct manner, the proposed new method computes and stores only the incoming radiance generated by the lightsources and the reflected radiance is obtained from the incoming radiance on the fly taking into account the local BRDF. Since the radiance function of the reflection is smoother and flatter than the original lightsource function, this replacement makes the integrand of the rendering equation have significantly smaller variation, which can speed up global illumination algorithms. The paper also discusses how the firstshot technique can be built into a stochastic iteration algorithm using raybundles, and provides runtime statistics.
MonteCarlo Methods In Global Illumination
, 2000
"... lightsources, such as point or directional lightsources are preferred here, since their radiance is a Diracdelta like function, which simplifies the integral of equation (2.50) to a sum. These methods take into account only a single reflection of the light coming from the abstract lightsources. Ide ..."
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Cited by 11 (7 self)
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lightsources, such as point or directional lightsources are preferred here, since their radiance is a Diracdelta like function, which simplifies the integral of equation (2.50) to a sum. These methods take into account only a single reflection of the light coming from the abstract lightsources. Ideal mirrors and refracting objects cannot be rendered with these methods. 2. Recursive raytracing Another alternative is to eliminate from the rendering equation those energy contributions which cause the difficulties, and thus give ourselves a simpler problem to solve. For example, if limited level, say n, coupling caused by ideal reflection and refraction were allowed, and we were to ignore the other nonideal components coming from nonabstract lightsources, then the number of surface points which would need to be evaluated to calculate a pixel color can be kept under control. Since the illumination formula contains two terms regarding the coherent components (reflective and refracting l...
Global Raybundle Tracing
, 1998
"... The paper presents a singlepass, viewdependent method to solve the general rendering equation, using a combined finite element and random walk approach. Applying finite element techniques, the surfaces are decomposed into planar patches on which the radiance is assumed to be combined from finite ..."
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Cited by 9 (7 self)
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The paper presents a singlepass, viewdependent method to solve the general rendering equation, using a combined finite element and random walk approach. Applying finite element techniques, the surfaces are decomposed into planar patches on which the radiance is assumed to be combined from finite number of unknown directional radiance functions by predefined positional basis functions. The directional radiance functions are then computed by random walk or by stochastic iteration using bundles of parallel rays. To compute the radiance transfer in a single direction, several global visibility methods are considered, including the global versions of the painter's, zbuffer, WeilerAtherton's and planar graph based algorithms. The method requires no preprocessing except for handling point lightsources, for which a firstshot technique is proposed. The proposed method is particularly efficient for scenes including not very specular materials illuminated by large area lightsources o...
A virtual light field approach to global illumination
 In Proceedings of Computer Graphics International (CGI 2004
, 2004
"... This paper describes an algorithm that provides realtime walkthrough for globally illuminated scenes that contain mixtures of ideal diffuse and specular surfaces. A type of light field data structure is used for propagating radiance outward from light emitters through the scene, accounting for any ..."
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Cited by 7 (5 self)
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This paper describes an algorithm that provides realtime walkthrough for globally illuminated scenes that contain mixtures of ideal diffuse and specular surfaces. A type of light field data structure is used for propagating radiance outward from light emitters through the scene, accounting for any kind of L(SD)* light path. The light field employed is constructed by choosing a regular point subdivision over a hemisphere, to give a set of directions, and then corresponding to each direction there is a rectangular grid of parallel rays. Each rectangular grid of rays is further subdivided into rectangular tiles, such that each tile references a sequence of 2D images containing colour values corresponding to the outgoing radiances of surfaces intersected by the rays in that tile. This structure is then used for final image rendering. Propagation times can be very long and the memory requirements very high. This algorithm, however, offers a global illumination solution for realtime walkthrough even on a single processor. 1.
Multiple Strategy Stochastic Iteration for Architectural Walkthroughs
"... Architectural walkthroughs require fast global illumination algorithms and also accurate results from certain viewpoints. This paper introduces a global illumination method that combines several strategies to meet the contradicting criteria of architectural walkthroughs. The methods include parall ..."
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Cited by 4 (0 self)
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Architectural walkthroughs require fast global illumination algorithms and also accurate results from certain viewpoints. This paper introduces a global illumination method that combines several strategies to meet the contradicting criteria of architectural walkthroughs. The methods include parallel and perspective raybundle shooting and ray shooting. Each method is designed to randomly approximate the effect of the light transport operator. Parallel raybundle tracing transfers the radiance of all points parallel to a randomly selected global direction, with perspective raybundles we can shoot the radiance of a single patch in all directions, and ray shooting transfers the radiance of a randomly selected point at a randomly selected direction. These strategies are of complementary character since each of them is effective in different illumination conditions. The proposed algorithm is iterative and the steps realized by different methods that randomly follow each other. In each step, the applied strategy is selected randomly according to the properties of the current radiance distribution, thus we can exploit that the used strategies are good in different conditions. The formal framework of their combination is the stochastic iteration. Although the final result is the image, i.e. the algorithm is view dependent, a rough approximation of the radiance function is stored in object space, that can allow fast movements at reasonable storage requirements and also speed up MonteCarlo simulations which result in the final image. The method is also suited for interactive walkthrough animation in glossy scenes since when the viewpoint changes, the object space radiance values remain valid and the image quickly adapts to the new situation.
Stochastic methods in global illumination: State of the art report
, 1998
"... This paper presents a state of the art report of those global illumination algorithms which involve MonteCarlo or quasiMonte Carlo techniques. First it surveys the basic tasks of global illumination, which can be formulated as the solution of either the rendering or the potential equation, then re ..."
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Cited by 4 (1 self)
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This paper presents a state of the art report of those global illumination algorithms which involve MonteCarlo or quasiMonte Carlo techniques. First it surveys the basic tasks of global illumination, which can be formulated as the solution of either the rendering or the potential equation, then reviews the basic solution techniques, including inversion, expansion and iteration. The paper explains why stochastic approaches are good to solve these integral equations and highlights what kind of fundamental choices we have when designing such an algorithm. It compares, for example, finiteelement and continuous methods, pure MonteCarlo and quasiMonte Carlo techniques, different versions of importance sampling, Russian roulette, local and global visibility algorithms, etc. Then, a lot of methods are reviewed in a unified framework, that also allows to make comparisons. Keywords: Rendering equation, potential equation, MonteCarlo and quasiMonte Carlo quadratures, finiteelement
Global Illumination as a Combination of Continuous Random Walk and FiniteElement Based Iteration
 Computer Graphics Forum
"... The paper introduces a global illumination method that combines continuous and finiteelement approaches, preserving the speed of finiteelement based iteration and the accuracy of continuous random walks. The basic idea is to decompose the radiance function to a finiteelement component that is onl ..."
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Cited by 3 (0 self)
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The paper introduces a global illumination method that combines continuous and finiteelement approaches, preserving the speed of finiteelement based iteration and the accuracy of continuous random walks. The basic idea is to decompose the radiance function to a finiteelement component that is only a rough estimate and to a difference component that is obtained by MonteCarlo techniques. Iteration and random walk are handled uniformly in the framework of stochastic iteration. This uniform treatment allows the finiteelement component to be built up adaptively aiming at minimizing the MonteCarlo component. The method is also suited for interactive walkthrough animation in glossy scenes since when the viewpoint changes, only the small MonteCarlo component needs to be recomputed. 1.
A Virtual Light Field for Propagation and Walkthrough of Globally Illuminated Scenes
 Proceedings of Computer Graphics International
, 1984
"... www.cs.ucl.ac.uk/vlf p.khanna  m.slater  j.mortensen  i.yu @ cs.ucl.ac.uk This paper describes an algorithm that provides realtime walkthrough for globally illuminated scenes comprising of ideal diffuse and specular polygonal surfaces. A type of light field data structure is used for propagating ..."
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Cited by 2 (0 self)
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www.cs.ucl.ac.uk/vlf p.khanna  m.slater  j.mortensen  i.yu @ cs.ucl.ac.uk This paper describes an algorithm that provides realtime walkthrough for globally illuminated scenes comprising of ideal diffuse and specular polygonal surfaces. A type of light field data structure is used for propagating radiance outward from light emitters through the scene and accounts for all L(SD) * light paths. The light field employed is constructed by choosing a regular point subdivision over a hemisphere, to give a set of directions, and then corresponding to each direction creating a rectangular grid of parallel rays. Each rectangular grid of rays, called a ‘parallel subfield ’ is further subdivided into rectangular tiles, such that each tile references a sequence of 2D “images ” containing colour values corresponding to the outgoing radiances of surfaces intersected by the rays belonging to that tile. Following propagation, this structure is used for final image rendering. Propagation times are currently very long and the memory requirements high. This algorithm, however, offers a global illumination solution for realtime walkthrough even on a single processor. 1.
Stream processing in global illumination
 in Proceedings of 8th Central European Seminar on Computer Graphics
, 2004
"... This paper presents the implementation of the stochastic radiosity algorithm on the graphics hardware. We store the radiosity function in texels of the floating point pbuffer. The radiosity function is updated in each iteration. When converged, the radiosity function is mapped onto surfaces by tradi ..."
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This paper presents the implementation of the stochastic radiosity algorithm on the graphics hardware. We store the radiosity function in texels of the floating point pbuffer. The radiosity function is updated in each iteration. When converged, the radiosity function is mapped onto surfaces by traditional texture mapping. Our goal is to enable interactive radiosity style rendering of scenes with moving objects and/or light sources.
MonteCarlo Global Illumination Methods  State of the Art and New Developments
, 1999
"... This paper presents the state of the art and recent developments of MonteCarlo global illumination algorithms. First it surveys the basic tasks of global illumination, which can be formulated as the solution of either the rendering or the potential equation, then reviews the basic solution techniqu ..."
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Cited by 1 (0 self)
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This paper presents the state of the art and recent developments of MonteCarlo global illumination algorithms. First it surveys the basic tasks of global illumination, which can be formulated as the solution of either the rendering or the potential equation, then reviews the basic solution techniques, including inversion, expansion and iteration. The paper explains why stochastic approaches are good to solve these integral equations and highlights what kind of fundamental choices we have when designing such an algorithm. It compares, for example, finiteelement and continuous methods, pure MonteCarlo and quasiMonte Carlo techniques, different versions of importance sampling, Russian roulette, etc. Then, a lot of methods are reviewed in a unified framework, that also allows to make comparisons.