An Integral geometry based method for fast form-factor computation

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.Postprint (published version

An Integral Geometry Based Method for Fast Form-Factor Computation

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 form-factor 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..

An Integral geometry based method for fast form-factor computation

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

A graphics processing unit based method for dynamic real-time global illumination

Real-time realistic image synthesis for virtual environments has been one of the most actively researched areas in computer graphics for over a decade. Images that display physically correct illumination of an environment can be simulated by evaluating a multi-dimensional integral equation, called the rendering equation, over the surfaces of the environment. Many global illumination algorithms such as pathtracing, photon mapping and distributed ray-tracing can produce realistic images but are generally unable to cope with dynamic lighting and objects at interactive rates. It still remains one of most challenging problems to simulate physically correctly illuminated dynamic environments without a substantial preprocessing step. In this thesis we present a rendering system for dynamic environments by implementing a customized rasterizer for global illumination entirely on the graphics hardware, the Graphical Processing Unit. Our research focuses on a parameterization of discrete visibility field for efficient indirect illumination computation. In order to generate the visibility field, we propose a CUDA-based (Compute Unified Device Architecture) rasterizer which builds Layered Hit Buffers (LHB) by rasterizing polygons into multi-layered structural buffers in parallel. The LHB provides a fast visibility function for any direction at any point. We propose a cone approximation solution to resolve an aliasing problem due to limited directional discretization. We also demonstrate how to remove structure noises by adapting an interleaved sampling scheme and discontinuity buffer. We show that a gathering method amortized with a multi-level Quasi Mont Carlo method can evaluate the rendering equation in real-time. The method can realize real-time walk-through of a complex virtual environment that has a mixture of diffuse and glossy reflection, computing multiple indirect bounces on the fly. We show that our method is capable of simulating fully dynamic environments including changes of view, materials, lighting and objects at interactive rates on commodity level graphics hardware