3D graphics eBook - Course Materials Repository

More documents

Recommendations

Info

Particle system 95 During the simulation stage, the number of new particles that must be created is calculated based on spawning rates and the interval between updates, and each of them is spawned in a specific position in 3D space based on the emitter's position and the spawning area specified. Each of the particle's parameters (i.e. velocity, color, etc.) is initialized according to the emitter's parameters. At each update, all existing particles are checked to see if they have exceeded their lifetime, in which case they are removed from the simulation. Otherwise, the particles' position and other characteristics are advanced based on some sort of physical simulation, which can be as simple as translating their current position, or as complicated as performing physically accurate trajectory calculations which take into account external forces (gravity, friction, wind, etc.). It is common to perform some sort of collision detection between particles and specified 3D objects in the scene to make the particles bounce off of or otherwise interact with obstacles in the environment. Collisions between particles are rarely used, as they are computationally expensive and not really useful for most simulations. Rendering stage After the update is complete, each particle is rendered, usually in the form of a textured billboarded quad (i.e. a quadrilateral that is always facing the viewer). However, this is not necessary; a particle may be rendered as a single pixel in small resolution/limited processing power environments. Particles can be rendered as Metaballs in off-line rendering; isosurfaces computed from particle-metaballs make quite convincing liquids. Finally, 3D mesh objects can "stand in" for the particles — a snowstorm might consist of a single 3D snowflake mesh being duplicated and rotated to match the positions of thousands or millions of particles. Snowflakes versus hair Particle systems can be either animated or static; that is, the lifetime of each particle can either be distributed over time or rendered all at once. The consequence of this distinction is the difference between the appearance of "snow" and the appearance of "hair." The term "particle system" itself often brings to mind only the animated aspect, which is commonly used to create moving particulate simulations — sparks, rain, fire, etc. In these implementations, each frame of the animation contains each particle at a specific position in its life cycle, and each particle occupies a single point position in space. However, if the entire life cycle of the each particle is rendered simultaneously, the result is static particles — strands of material that show the particles' overall trajectory, rather than point particles. These strands can be used to simulate hair, fur, grass, and similar materials. The strands can be controlled with the same velocity vectors, force fields, spawning rates, and deflection parameters that animated particles obey. In addition, the rendered thickness of the strands can be controlled and in some implementations may be varied along the length of the strand. Different combinations of parameters can impart stiffness, limpness, heaviness, bristliness, or any number of other properties. The strands may also use texture mapping to vary the strands' color, length, or other properties across the emitter surface.
Particle system 96 A cube emitting 5000 animated particles, obeying a "gravitational" force in the negative Y direction. Artist-friendly particle system tools The same cube emitter rendered using static particles, or strands. Particle systems can be created and modified natively in many 3D modeling and rendering packages including Cinema 4D, Lightwave, Houdini, Maya, XSI, 3D Studio Max and Blender. These editing programs allow artists to have instant feedback on how a particle system will look with properties and constraints that they specify. There is also plug-in software available that provides enhanced particle effects; examples include AfterBurn and RealFlow (for liquids). Compositing software such as Combustion or specialized, particle-only software such as Particle Studio and particleIllusion can be used for the creation of particle systems for film and video. Developer-friendly particle system tools Particle systems code that can be included in game engines, digital content creation systems, and effects applications can be written from scratch or downloaded. One free implementation is The Particle Systems API [1] (Development ended in 2008). Another for the XNA framework is the Dynamic Particle System Framework [2] . Havok provides multiple particle system APIs. Their Havok FX API focuses especially on particle system effects. Ageia provides a particle system and other game physics API that is used in many games, including Unreal Engine 3 games. In February 2008, Ageia was bought by Nvidia. External links • Particle Systems: A Technique for Modeling a Class of Fuzzy Objects [3] — William T. Reeves (ACM Transactions on Graphics, April 1983) • The Particle Systems API [1] - David K. McAllister • The ocean spray in your face. [4] — Jeff Lander (Game Developer, July 1998) • Building an Advanced Particle System [5] — John van der Burg (Gamasutra, June 2000) • Particle Engine Using Triangle Strips [6] — Jeff Molofee (NeHe) • Designing an Extensible Particle System using C++ and Templates [7] — Kent Lai (GameDev) • repository of public 3D particle scripts in LSL Second Life format [8] - Ferd Frederix
Page 1 and 2:
3D Rendering PDF generated using th
Page 3 and 4:
Image-based lighting 64 Image plane
Page 5 and 6:
References Article Sources and Cont
Page 7 and 8:
3D rendering 2 Non real-time Animat
Page 9 and 10:
3D rendering 4 The shaded three-dim
Page 11 and 12:
Ambient occlusion 6 ambient occlusi
Page 13 and 14:
Ambient occlusion 8 • ShadeVis (h
Page 15 and 16:
Anisotropic filtering 10 will only
Page 17 and 18:
Beam tracing 12 Beam tracing Beam t
Page 19 and 20:
Bilinear filtering 14 Are all true.
Page 21 and 22:
Binary space partitioning 16 togeth
Page 23 and 24:
Binary space partitioning 18 Other
Page 25 and 26:
Binary space partitioning 20 [1] Bi
Page 27 and 28:
Bounding interval hierarchy 22 Prop
Page 29 and 30:
Bounding volume 24 bounding boxes b
Page 31 and 32:
Bump mapping 26 Bump mapping Bump m
Page 33 and 34:
CatmullClark subdivision surface 28
Page 35 and 36:
CatmullClark subdivision surface 30
Page 37 and 38:
Conversion between quaternions and
Page 39 and 40:
Cube mapping 34 Advantages Cube map
Page 41 and 42:
Cube mapping 36 Related A large set
Page 43 and 44:
Diffuse reflection 38 2), or, of co
Page 45 and 46:
Displacement mapping 40 Meaning of
Page 47 and 48:
DooSabin subdivision surface 42 Ext
Page 49 and 50: False radiosity 44 False radiosity
Page 51 and 52: Geometry pipelines 46 Geometry pipe
Page 53 and 54: Global illumination 48 Rendering wi
Page 55 and 56: Gouraud shading 50 Gouraud shading
Page 57 and 58: Graphics pipeline 52 Graphics pipel
Page 59 and 60: Graphics pipeline 54 References 1.
Page 61 and 62: Hidden surface determination 56 imp
Page 63 and 64: High dynamic range rendering 58 Hig
Page 65 and 66: High dynamic range rendering 60 Ton
Page 67 and 68: High dynamic range rendering 62 Fro
Page 69 and 70: High dynamic range rendering 64 •
Page 71 and 72: Irregular Z-buffer 66 Applications
Page 73 and 74: Lambert's cosine law 68 than would
Page 75 and 76: Lambertian reflectance 70 Lambertia
Page 77 and 78: Level of detail 72 Well known appro
Page 79 and 80: Level of detail 74 Hierarchical LOD
Page 81 and 82: Newell's algorithm 76 Newell's algo
Page 83 and 84: Non-uniform rational B-spline 78 Us
Page 85 and 86: Non-uniform rational B-spline 80 of
Page 87 and 88: Non-uniform rational B-spline 82 ar
Page 89 and 90: Non-uniform rational B-spline 84 Ex
Page 91 and 92: Normal mapping 86 How it works To c
Page 93 and 94: OrenNayar reflectance model 88 Oren
Page 95 and 96: OrenNayar reflectance model 90 , ,
Page 97 and 98: Painter's algorithm 92 The algorith
Page 99: Parallax mapping 94 • Parallax Ma
Page 103 and 104: Path tracing 98 History Further inf
Page 105 and 106: Path tracing 100 Scattering distrib
Page 107 and 108: Phong reflection model 102 Visual i
Page 109 and 110: Phong reflection model 104 Because
Page 111 and 112: Phong shading 106 Visual illustrati
Page 113 and 114: Photon mapping 108 Rendering (2nd p
Page 115 and 116: Photon tracing 110 Advantages and d
Page 117 and 118: Potentially visible set 112 • Can
Page 119 and 120: Potentially visible set 114 Externa
Page 121 and 122: Procedural generation 116 increases
Page 123 and 124: Procedural generation 118 • Softi
Page 125 and 126: Procedural generation 120 Reference
Page 127 and 128: Procedural texture 122 Self-organiz
Page 129 and 130: Procedural texture 124 References [
Page 131 and 132: 3D projection 126 The distance of t
Page 133 and 134: Quaternions and spatial rotation 12
Page 145 and 146: Radiosity 140 Overview of the radio
Page 147 and 148: Radiosity 142 This is sometimes kno
Page 149 and 150: Radiosity 144 References [1] " Mode
Page 151 and 152:
Ray casting 146 the light will reac
Page 153 and 154:
Ray tracing 148 Typically, each ray
Page 155 and 156:
Ray tracing 150 independence of eac
Page 157 and 158:
Ray tracing 152 On June 12, 2008 In
Page 159 and 160:
Reflection 154 Reflection Reflectio
Page 161 and 162:
Reflection 156 Glossy Reflection Fu
Page 163 and 164:
Reflection mapping 158 Cube mapping
Page 165 and 166:
Render Output unit 160 Render Outpu
Page 167 and 168:
Rendering 162 • indirect illumina
Page 169 and 170:
Rendering 164 Ray tracing Ray traci
Page 171 and 172:
Rendering 166 Academic core The imp
Page 173 and 174:
Rendering 168 • 1984 Distributed
Page 175 and 176:
Retained mode 170 Retained mode In
Page 177 and 178:
Scanline rendering 172 Comparison w
Page 179 and 180:
Screen Space Ambient Occlusion 174
Page 181 and 182:
Screen Space Ambient Occlusion 176
Page 183 and 184:
Shadow mapping 178 Algorithm overvi
Page 185 and 186:
Shadow mapping 180 Drawing the scen
Page 187 and 188:
Shadow mapping 182 Further reading
Page 189 and 190:
Shadow volume 184 There is also a p
Page 191 and 192:
Shadow volume 186 The depth fail me
Page 193 and 194:
Silhouette edge 188 Silhouette edge
Page 195 and 196:
Specular highlight 190 Specular hig
Page 197 and 198:
Specular highlight 192 normalized o
Page 199 and 200:
Sphere mapping 194 Sphere mapping I
Page 201 and 202:
Stencil codes 196 Stencil codes Ste
Page 203 and 204:
Stencil codes 198 Stencils The shap
Page 205 and 206:
Stencil codes 200 [7] Wellein, G et
Page 207 and 208:
Subdivision surface 202 used a four
Page 209 and 210:
Subsurface scattering 204 Subsurfac
Page 211 and 212:
Subsurface scattering 206 External
Page 213 and 214:
Surface normal 208 If a (possibly n
Page 215 and 216:
Surface normal 210 Normal in geomet
Page 217 and 218:
Texture filtering 212 Texture filte
Page 219 and 220:
Texture mapping 214 Texture mapping
Page 221 and 222:
Texture mapping 216 constant distan
Page 223 and 224:
Texture synthesis 218 • Structure
Page 225 and 226:
Texture synthesis 220 Pattern-based
Page 227 and 228:
Texture synthesis 222 • Micro-tex
Page 229 and 230:
UV mapping 224 A UV map can either
Page 231 and 232:
Vertex 226 Polytope vertices are re
Page 233 and 234:
Vertex Buffer Object 228 //Make the
Page 235 and 236:
Vertex Buffer Object 230 GLuint sha
Page 237 and 238:
Vertex Buffer Object 232 vertexes *
Page 239 and 240:
Virtual actor 234 Virtual actor A v
Page 241 and 242:
Virtual actor 236 exercises, and ev
Page 243 and 244:
Volume rendering 238 Volume ray cas
Page 245 and 246:
Volume rendering 240 Maximum intens
Page 247 and 248:
Volume rendering 242 Image-based me
Page 249 and 250:
Volumetric lighting 244 References
Page 251 and 252:
Voxel 246 • Outcast, a game made
Page 253 and 254:
Z-buffering 248 Z-buffering In comp
Page 255 and 256:
Z-buffering 250 } } display COLOR a
Page 257 and 258:
Z-fighting 252 Z-fighting Z-fightin
Page 259 and 260:
Appendix 3D computer graphics softw
Page 261 and 262:
3D computer graphics software 256
Page 263 and 264:
3D computer graphics software 258
Page 265 and 266:
3D computer graphics software 260 2
Page 267 and 268:
Article Sources and Contributors 26
Page 269 and 270:
Article Sources and Contributors 26
Page 271 and 272:
Image Sources, Licenses and Contrib
Page 273 and 274:
Image Sources, Licenses and Contrib
show all

3D graphics eBook - Course Materials Repository

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?