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12
An Integral Geometry Based Method for Fast FormFactor Computation
 Computer Graphics Forum (Eurographics
, 1993
"... Monte Carlo techniques have been widely used in rendering algorithms for local integration. For example, to compute the contribution of a patch to the luminance of another. In the present paper we propose an algorithm based on Integral geometry where Monte Carlo is applied globally. We give some res ..."
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Cited by 31 (16 self)
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Monte Carlo techniques have been widely used in rendering algorithms for local integration. For example, to compute the contribution of a patch to the luminance of another. In the present paper we propose an algorithm based on Integral geometry where Monte Carlo is applied globally. We give some results of the implementation to validate the proposition and we study the error of the technique, as well as its complexity. 1. INTRODUCTION Monte Carlo methods in radiative heat transfer, and thereafter in radiosity, can be classified in two: those that ignore the formfactor matrix and only need a final solution, and those which explicitly give the form factor matrix and solve a posteriori the equations system. [Shamsundar73], [Pattanaik92] and [Shirley90] fall into the first category, while [Weiner65] belongs to the second. The first category is more suitable for a quick solution, while the second allows the possibility of changing the problem's initial conditions of illumination. As [Sie...
Anisotropic Diffusion for Monte Carlo Noise Reduction
"... Monte Carlo sampling can be used to estimate solutions to global light transport and other rendering problems. However, a large number of observations may be needed to reduce the variance to acceptable levels. Rather than computing more observations within each pixel, if spatial coherence exists in ..."
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Cited by 24 (0 self)
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Monte Carlo sampling can be used to estimate solutions to global light transport and other rendering problems. However, a large number of observations may be needed to reduce the variance to acceptable levels. Rather than computing more observations within each pixel, if spatial coherence exists in image space it can be used to reduce visual error by averaging estimators in adjacent pixels. Anisotropic diffusion is a spacevariant noise reduction technique that can selectively preserve texture, edges, and other details using a map of image coherence. The coherence map can be estimated from depth and normal information as well as interpixel colour distances. Incremental estimation of the reduction in variance, in conjunction with statistical normalization of interpixel colour distances, yields an energypreserving algorithm that converges to a spatially nonconstant steady state.
Concrete Computation of Global Illumination Using Structured Sampling
 3rd Eurographics Workshop on Rendering
, 1992
"... A new methodology is presented for the computation of global illumination using structured sampling. Analytical/numerical solutions for illumination are developed for simple lighting configurations. These solutions are subsequently used to generate accurate reference images. The structured sampling ..."
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Cited by 9 (4 self)
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A new methodology is presented for the computation of global illumination using structured sampling. Analytical/numerical solutions for illumination are developed for simple lighting configurations. These solutions are subsequently used to generate accurate reference images. The structured sampling solution for global illumination is then discussed, comprising sample placement for illumination calculation, reconstruction for light transfer and finally resampling and filtering of illumination samples for display. A first approximation to this technique is presented using a priori placement of samples, irregular polygon reflectors, grid resampling and a conical filter for display. The new algorithm is evaluated for image quality, and compared to the traditional radiositybased approach. These first results show that the structured sampling solution yields significant computational savings while maintaining high image quality. 1. Goals of the Approach The calculation of global illumination is inherently complex, even for environments that are simple
Analytic Signal Processing for Computer Graphics using Multivariate Polyhedral Splines
, 1995
"... Multivariate polyhedral splines can be used to solve a common image synthesis problem: multivariate integrals defined over multiple geometrically defined domains. The theory is extended from applications in geometric design; this involves both the loosening of some overly restrictive assumptions as ..."
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Cited by 6 (1 self)
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Multivariate polyhedral splines can be used to solve a common image synthesis problem: multivariate integrals defined over multiple geometrically defined domains. The theory is extended from applications in geometric design; this involves both the loosening of some overly restrictive assumptions as well as the introduction of hybridization, slicing, and weighted splines. Two applications are explored: analytic convolutional filtering for antialiasing and evaluation of projected reconstruction kernels for volume rendering. Filtering can be performed in the continuous domain for high quality antialiasing via Bspline filters. We extensively study a linearly interpolated, filtered triangle. Volume rendering via a linear splatting algorithm can be improved by using a box spline interpolation kernel. This approach avoids aliasing and reconstruction problems, allows progressive rendering directly from hierarchically compressed data, and allows precise evaluation of derivatives, which are necessary for shading. Both antialiasing and volume rendering can benefit from the close connection between continuous and discrete signal processing provided by the Bspline basis. An infinite extent analytic cardinal spline filter is equivalent to an analytic Bspline filter followed by a twopass
Computational Requirements for Accelerating Radiosity Algorithms
, 1993
"... A major problem in realistic image synthesis is the solution of the rendering equation. ..."
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Cited by 1 (0 self)
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A major problem in realistic image synthesis is the solution of the rendering equation.
RealTime Realistic Rendering . . .
, 2005
"... This dissertation focuses on the many issues that arise from the visual rendering problem. Of primary consideration is light transport simulation, which is known to be computationally expensive. Monte Carlo methods represent a simple and general class of algorithms often used for light transport com ..."
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This dissertation focuses on the many issues that arise from the visual rendering problem. Of primary consideration is light transport simulation, which is known to be computationally expensive. Monte Carlo methods represent a simple and general class of algorithms often used for light transport computation. Unfortunately, the images resulting from Monte Carlo approaches generally suffer from visually unacceptable noise artifacts. The result of any light transport simulation is, by its very nature, an image of high dynamic range (HDR). This leads to the issues of the display of such images on conventional low dynamic range devices and the development of data compression algorithms to store and recover the corresponding large amounts of detail found in HDR images. This dissertation presents our contributions relevant to these issues. Our contributions to high dynamic range image processing include tone mapping and data compression algorithms. This research proposes and shows the efficacy of a novel level set based tone mapping method that preserves visual details in the display of high dynamic range images on low dynamic range display devices. The level set method is used to extract the high
A Multimode Immersive Conceptual Design System for Architectural Modeling and Lighting
"... We present a new immersive system which allows initial conceptual design of simple architectural models, including lighting. Our system allows the manipulation of simple elements such as windows, doors and rooms while the overall model is automatically adjusted to the manipulation. The system runs o ..."
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We present a new immersive system which allows initial conceptual design of simple architectural models, including lighting. Our system allows the manipulation of simple elements such as windows, doors and rooms while the overall model is automatically adjusted to the manipulation. The system runs on a foursided stereoscopic, headtracked immersive display. We also provide simple lighting design capabilities, with an abstract representation of sunlight and its effects when shining through a window. Our system provides three different modes of interaction, a miniaturemodel table mode, a fullscale immersive mode and a combination of table and immersive which we call mixed mode. We performed an initial pilot user test to evaluate the relative merits of each mode for a set of basic tasks such as resizing and moving windows or walls, and a basic lightmatching task. The study indicates that users appreciated the immersive nature of the system, and found interaction to be natural and pleasant. In addition, the results indicate that the mean performance times seem quite similar in the different modes, opening up the possibility for their combined usage for effective immersive modeling systems for novice users. 1
A Compiled Source Access System Using CDROM and Personal Computers, by
"... 65 CMOS Device Measurement Results ..."
1.)n Sharing Access to Display Resources in the Starbase/Xl 1 Merge System, by Jeff
, 1989
"... (J XWinOowSystem, byKennethH.Bronstein,DavidJ. Sweetser, andWilliamR.Yoder ..."
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(J XWinOowSystem, byKennethH.Bronstein,DavidJ. Sweetser, andWilliamR.Yoder