Index_P

P

painterly rendering style, 81

parallelepiped, defined by vectors, 20, 21

parallelogram, formed by two vectors, 19

partial precision, specifying (_pp) modifier, 296

partial precision declaration modifier, 369

partial precision log₂, computing, 231-234

partial precision modifier (_pp), applying to the declaration statement, 211

partial precision power of two, computing, 221

pen and ink style, 81-82

per-polygon normals, 42

per vertex fog values, setting, 168

per-vertex normals, 42

perfect isotropic reflection, 39

perfect reflectors, all surfaces becoming, 69

perpendicular phase, of the electric and magnetic fields in a wave of energy, 64, 65

perspective divide

performing in the pixel shader, 362

performing on fetched texture coordinates, 333

perspective projection, performing on texture coordinates before texture sampling, 341

perturbation data, transformed by a 2 × 2 bump environment-mapping matrix, 328, 329-330

phase instruction, 274, 275, 319-320

phase one instructions, 319

phase two instructions, 319

Phong's lighting equation, implementing Blinn's simplification to, 162

Phong's specular equation, compared to Blinn's, 49

Phong's specular light equation, 45-48

physically based illumination, 58-74

physically based surface models, 74-76

piecewise addition, notation for, 11

piecewise multiplication

of color values, 25

notation for, 11

pigment-saturated translucent coatings, subsurface scattering of, 36, 37

pipeline, from vertex data to rendering, 129

Pixar's RenderMan, 3

pixel-blending section of the multitexture section, of the FFP, 93

pixel registers, range clamped to, 110

pixel shader code, defining the version being used, 321-322

pixel shader constants, setting, 136

pixel shader reference, 273-371

pixel shaders, 90, 107-111, 273

adding diffuse and specular colors, 109

assembling, 130-132

breaking up into two sections, 319-320

checking for supported versions of, 116

creating and using, 130

def statements in, 133

determining how textures get blended, 177

higher precision registers in DirectX 9, 279

instructions for, 273

loading, 133

output of, 94

replacing sections of the fixed function

pipeline (FFP), 91-92

revision history of, 279-281

technical overview, 93-94

texture addressing in version 2.0, 276

unique behavior between shader versions, 109

version 1.0 through 1.3, 274

version 1.4, 275

version 2.0, 276

versions 2.0 or better, 109

versions of, 273

vertex fog value inaccessible to, 204

pixels

calculating the color of particular, 24

calculating the z and w depth values of, 343

hardware accelerated method of manipulating, 111

terminating processing if texture coordinates or registers are less than 0, 337

tracing through scenes, 5

plane, defining in 3-space, 17

point primitives, adding "detail" to a scene, 172

point size, varying, 173

point size register (oPts), 172, 204

point size shader, 172-174

point size vector component, FVF vertex shader register mapping order, 199

point sprites, 173

points, 10, 12, 13

Poisson, Simeon Denis, 67

Poisson's bright spot, 67

polarization angele, 68-69

polarized lenses, 68

polarized light, fraction transmitted and reflected, 66

position 2 vector component, FVF vertex shader register mapping order, 199

position vector component, FVF vertex shader register mapping order, 199

positional light. See also local light

Lambertian diffuse lighting with, 158-161

Poulin-Fourier model, replacing randomly oriented v-shaped grooves with aligned cylindrical shapes, 78-79

pow macro, 255-256, 320-321

power function, computing for a scalar value, 255, 320-321

_pp (partial precision hint) modifier, 296, 368, 369

precision, indicating a lower for a register, 211

primitive calls, 137

printed images, manipulating to look like screen image, 23

printers, gamuts of, 24

prism, passing white light triangle, 62, 63

projection matrix, calculating, 99

PS 1.0 through 1.3, 274, 281

PS 1.1 through 1.3, 285

PS 1.4, 275, 280-281, 285

PS 2.0, 276, 280

texture addressing, 276

texture registers in, 285

ps instruction, 321-322

"pure" device, specifying, 115