GPU-BASED TECHNIQUES FOR GLOBAL ILLUMINATION EFFECTS

Laszlo Szirmay-Kalos9781598295597, 1598295594, 1598295608

This book presents techniques to render photo-realistic images by programming the Graphics Processing Unit (GPU). We discuss effects such as mirror reflections, refractions, caustics, diffuse or glossy indirect illumination, radiosity, single or multiple scattering in participating media, tone reproduction, glow, and depth of field. The book targets game developers, graphics programmers, and also students with some basic understanding of computer graphics algorithms, rendering APIs like Direct3D or OpenGL, and shader programming. In order to make the book self-contained, the most important concepts of local illumination and global illumination rendering, graphics hardware, and Direct3D/HLSL programming are reviewed in the first chapters. After these introductory chapters we warm up with simple methods including shadow and environment mapping, then we move on toward advanced concepts aiming at global illumination rendering. Since it would have been impossible to give a rigorous review of all approaches proposed in this field, we go into the details of just a few methods solving each particular global illumination effect. However, a short discussion of the state of the art and links to the bibliography are also provided to refer the interested reader to techniques that are not detailed in this book. The implementation of the selected methods is also presented in HLSL, and we discuss their observed performance, merits, and disadvantages. In the last chapter, we also review how these techniques can be integrated in an advanced game engine and present case studies of their exploitation in games. Having gone through this book, the reader will have an overview of the state of the art, will be able to apply and improve these techniques, and most importantly, will be capable of developing brand new GPU algorithms.

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Table of contents :
C00.pdf……Page 1
GLOBAL ILLUMINATION RENDERING……Page 27
Materials……Page 32
Rendering equation……Page 34
Local illumination……Page 36
Global illumination……Page 39
Random walk solution of the renderingequation……Page 40
Monte Carlo Integration……Page 43
Importance Sampling……Page 45
Iteration solution of the rendering equation……Page 46
Application of former GI research results in GPUGI……Page 48
C02.pdf……Page 49
Evolution of the fixed-function rendering pipeline……Page 52
Rasterization With Linear Interpolation……Page 53
Texturing……Page 55
Transformation……Page 57
Programmable GPUs……Page 60
The Geometry Shader……Page 62
Pipeline Stages and Their Control by Render States……Page 64
PROGRAMMING AND CONTROLLING GPUS……Page 68
Introduction to HLSL programming……Page 70
Vertex Shader Programming……Page 72
Fragment Shader Programming……Page 75
Controlling the GPU from the CPU……Page 76
Controlling the Direct3D 9 Pipeline……Page 77
Controlling the Pipeline Using Effect Files……Page 82
Shaders beyond the standard pipelineoperation……Page 86
Are GPUs Good for Global Illumination?……Page 87
Basic Techniques for GPU Global Illumination……Page 88
SIMPLE IMPROVEMENTS OF THE LOCALILLUMINATION MODEL……Page 92
SHADOW MAPPING……Page 94
Shadow Map Generation……Page 96
Rendering With the Shadow Map……Page 97
Shadow Map Anti-aliasing……Page 100
IMAGE-BASED LIGHTING……Page 103
Mirrored Reflections and Refractions……Page 106
Diffuse and Glossy Reflections Without Self-shadowing……Page 108
Diffuse and Glossy Reflections With Shadowing……Page 111
RAY CASTING ON THE GPU……Page 116
RAY–TRIANGLE INTERSECTION IN A SHADER……Page 117
THE RAY ENGINE……Page 121
ACCELERATION HIERARCHY BUILT ON RAYS……Page 123
Implementation of Recursive Ray-tracing Using the Ray Engine……Page 124
Ray Casting……Page 126
FULL RAY-TRACERS ON THE GPU USING SPACEPARTITIONING……Page 128
Uniform Grid……Page 129
Hierarchical Bounding Boxes……Page 130
Kd-Tree……Page 131
LOOSE kd-TREE TRAVERSAL IN A SINGLE SHADER……Page 133
GPU Representation of the Loose kd-tree……Page 135
GPU Traversal of the Loose kd-tree……Page 137
Performance……Page 141
SPECULAR EFFECTS WITH RASTERIZATION……Page 142
RAY-TRACING OF DISTANCE MAPS……Page 146
Parallax Correction……Page 147
Linear Search……Page 148
Refinement by Secant Search……Page 150
SINGLE LOCALIZED REFLECTIONS AND REFRACTIONS……Page 152
SPECULAR REFLECTIONS WITH SEARCHING ONTHE REFLECTOR……Page 156
SPECULAR REFLECTIONS WITH GEOMETRY OR IMAGE TRANSFORMATION……Page 157
SELF REFLECTIONS AND REFRACTIONS……Page 158
CAUSTICS……Page 162
Light Pass……Page 163
Photon Hit Filtering and Light Projection……Page 165
COMBINING DIFFERENT SPECULAR EFFECTS……Page 170
DIFFUSE AND GLOSSY INDIRECT ILLUMINATION……Page 172
RADIOSITY ON THE GPU……Page 174
Random Texel Selection……Page 177
Update of the Radiance Texture……Page 179
PRE-COMPUTED RADIOSITY……Page 183
DIFFUSE AND GLOSSY FINAL GATHERING WITHDISTANCE MAPS……Page 185
PRE-COMPUTATION AIDED GLOBAL ILLUMINATION……Page 194
FINITE-ELEMENT METHOD……Page 197
Compression of Transfer Coefficients……Page 199
PRE-COMPUTED RADIANCE TRANSFER……Page 201
Direct3D Support of the Diffuse Pre-computed Radiance Transfer……Page 205
LIGHT PATH MAP……Page 208
Implementation……Page 210
C09.pdf……Page 221
PARTICLE SYSTEM MODEL……Page 223
BILLBOARD RENDERING……Page 224
Spherical Billboards……Page 225
ILLUMINATING PARTICIPATING MEDIA……Page 230
Dust and Smoke……Page 231
Fire……Page 232
Layer Composition……Page 235
PARTICIPATING MEDIA ILLUMINATION NETWORKS……Page 236
Iteration Solution of the Volumetric Rendering Equation……Page 237
Building the Illumination Network……Page 238
Iterating the Illumination Network……Page 239
FAKE GLOBAL ILLUMINATION……Page 244
THE SCALAR OBSCURANCES METHOD……Page 246
THE SPECTRAL OBSCURANCES METHOD……Page 247
CONSTRUCTION OF THE OBSCURANCES MAP……Page 249
DEPTH PEELING……Page 251
IMAGE FILTERING……Page 255
Separation of Dimensions……Page 257
Exploitation of the Bi-linear Filtering Hardware……Page 258
Importance Sampling……Page 260
TONE MAPPING……Page 262
Local Tone Mapping……Page 264
Temporal Luminance Adaptation……Page 265
Scotopic Vision……Page 266
Implementation……Page 267
DEPTH OF FIELD……Page 268
Camera Models and Depth of Field……Page 269
Depth of Field With the Simulation of Circle of Confusion……Page 270
INTEGRATING GI EFFECTS IN GAMES AND VIRTUAL REALITY SYSTEMS……Page 274
GAME ENGINES AND SCENE GRAPH MANAGERS……Page 275
COMBINING DIFFERENT RENDERING ALGORITHMS……Page 279
CASE STUDIES……Page 282
Moria……Page 283
RT Car……Page 285
Space Station……Page 289
C03.pdf……Page 69
C06.pdf……Page 143
C07.pdf……Page 173
C08.pdf……Page 195
C11.pdf……Page 245