| 1 |
#ifndef lint |
| 2 |
static const char RCSid[] = "$Id$"; |
| 3 |
#endif |
| 4 |
/* |
| 5 |
================================================================== |
| 6 |
Photon map support routines for scattering by materials. |
| 7 |
|
| 8 |
Roland Schregle (roland.schregle@{hslu.ch, gmail.com}) |
| 9 |
(c) Fraunhofer Institute for Solar Energy Systems, |
| 10 |
(c) Lucerne University of Applied Sciences and Arts, |
| 11 |
supported by the Swiss National Science Foundation (SNSF, #147053) |
| 12 |
================================================================== |
| 13 |
|
| 14 |
$Id: pmapmat.c,v 2.7 2015/05/27 17:54:19 rschregle Exp $ |
| 15 |
*/ |
| 16 |
|
| 17 |
|
| 18 |
|
| 19 |
#include "pmapmat.h" |
| 20 |
#include "pmapdata.h" |
| 21 |
#include "pmaprand.h" |
| 22 |
#include "otypes.h" |
| 23 |
#include "data.h" |
| 24 |
#include "func.h" |
| 25 |
#include "bsdf.h" |
| 26 |
#include <math.h> |
| 27 |
|
| 28 |
|
| 29 |
|
| 30 |
/* Stuff ripped off from material modules */ |
| 31 |
#define MAXITER 10 |
| 32 |
#define SP_REFL 01 |
| 33 |
#define SP_TRAN 02 |
| 34 |
#define SP_PURE 04 |
| 35 |
#define SP_FLAT 010 |
| 36 |
#define SP_BADU 040 |
| 37 |
#define MLAMBDA 500 |
| 38 |
#define RINDEX 1.52 |
| 39 |
#define FRESNE(ci) (exp(-5.85*(ci)) - 0.00287989916) |
| 40 |
|
| 41 |
|
| 42 |
|
| 43 |
typedef struct { |
| 44 |
OBJREC *mp; |
| 45 |
RAY *rp; |
| 46 |
short specfl; |
| 47 |
COLOR mcolor, scolor; |
| 48 |
FVECT vrefl, prdir, pnorm; |
| 49 |
double alpha2, rdiff, rspec, trans, tdiff, tspec, pdot; |
| 50 |
} NORMDAT; |
| 51 |
|
| 52 |
typedef struct { |
| 53 |
OBJREC *mp; |
| 54 |
RAY *rp; |
| 55 |
short specfl; |
| 56 |
COLOR mcolor, scolor; |
| 57 |
FVECT vrefl, prdir, u, v, pnorm; |
| 58 |
double u_alpha, v_alpha, rdiff, rspec, trans, tdiff, tspec, pdot; |
| 59 |
} ANISODAT; |
| 60 |
|
| 61 |
typedef struct { |
| 62 |
OBJREC *mp; |
| 63 |
RAY *pr; |
| 64 |
FVECT pnorm; |
| 65 |
FVECT vray; |
| 66 |
double sr_vpsa [2]; |
| 67 |
RREAL toloc [3][3]; |
| 68 |
RREAL fromloc [3][3]; |
| 69 |
double thick; |
| 70 |
SDData *sd; |
| 71 |
COLOR runsamp; |
| 72 |
COLOR rdiff; |
| 73 |
COLOR tunsamp; |
| 74 |
COLOR tdiff; |
| 75 |
} BSDFDAT; |
| 76 |
|
| 77 |
|
| 78 |
|
| 79 |
extern const SDCDst SDemptyCD; |
| 80 |
|
| 81 |
/* Per-material scattering function dispatch table; return value is usually |
| 82 |
* zero, indicating photon termination */ |
| 83 |
int (*photonScatter [NUMOTYPE]) (OBJREC*, RAY*); |
| 84 |
|
| 85 |
/* List of antimatter sensor modifier names and associated object set */ |
| 86 |
char *photonSensorList [MAXSET + 1] = {NULL}; |
| 87 |
static OBJECT photonSensorSet [MAXSET + 1] = {0}; |
| 88 |
|
| 89 |
|
| 90 |
|
| 91 |
/* ================ General support routines ================ */ |
| 92 |
|
| 93 |
|
| 94 |
void photonRay (const RAY *rayIn, RAY *rayOut, |
| 95 |
int rayOutType, COLOR fluxAtten) |
| 96 |
/* Spawn a new photon ray from a previous one; this is effectively a |
| 97 |
* customised rayorigin(). |
| 98 |
* A SPECULAR rayOutType flags this photon as _caustic_ for subsequent hits. |
| 99 |
* It is preserved for transferred rays (of type PMAP_XFER). |
| 100 |
* fluxAtten specifies the RGB attenuation of the photon flux effected by |
| 101 |
* the scattering material. The outgoing flux is then normalised to maintain |
| 102 |
* a uniform average of 1 over RGB. If fluxAtten == NULL, the flux remains |
| 103 |
* unchanged for the outgoing photon. fluxAtten is ignored for transferred |
| 104 |
* rays. |
| 105 |
* The ray direction is preserved for transferred rays, and undefined for |
| 106 |
* scattered rays and must be subsequently set by the caller. */ |
| 107 |
{ |
| 108 |
rayorigin(rayOut, rayOutType, rayIn, NULL); |
| 109 |
|
| 110 |
/* Transfer flux */ |
| 111 |
copycolor(rayOut -> rcol, rayIn -> rcol); |
| 112 |
|
| 113 |
/* Copy caustic flag & direction for transferred rays */ |
| 114 |
if (rayOutType == PMAP_XFER) { |
| 115 |
/* rayOut -> rtype |= rayIn -> rtype & SPECULAR; */ |
| 116 |
rayOut -> rtype |= rayIn -> rtype; |
| 117 |
VCOPY(rayOut -> rdir, rayIn -> rdir); |
| 118 |
} |
| 119 |
else if (fluxAtten) { |
| 120 |
/* Attenuate and normalise flux for scattered rays */ |
| 121 |
multcolor(rayOut -> rcol, fluxAtten); |
| 122 |
colorNorm(rayOut -> rcol); |
| 123 |
} |
| 124 |
|
| 125 |
/* Propagate index of emitting light source */ |
| 126 |
rayOut -> rsrc = rayIn -> rsrc; |
| 127 |
} |
| 128 |
|
| 129 |
|
| 130 |
|
| 131 |
static void addPhotons (const RAY *r) |
| 132 |
/* Insert photon hits, where applicable */ |
| 133 |
{ |
| 134 |
if (!r -> rlvl) |
| 135 |
/* Add direct photon map at primary hitpoint */ |
| 136 |
addPhoton(directPmap, r); |
| 137 |
else { |
| 138 |
/* Add global or precomputed photon map at indirect hitpoint */ |
| 139 |
addPhoton(preCompPmap ? preCompPmap : globalPmap, r); |
| 140 |
|
| 141 |
/* Store caustic photon if specular flag set */ |
| 142 |
if (PMAP_CAUSTICRAY(r)) |
| 143 |
addPhoton(causticPmap, r); |
| 144 |
|
| 145 |
/* Store in contribution photon map */ |
| 146 |
addPhoton(contribPmap, r); |
| 147 |
} |
| 148 |
} |
| 149 |
|
| 150 |
|
| 151 |
|
| 152 |
void getPhotonSensors (char **sensorList) |
| 153 |
/* Find antimatter geometry declared as photon sensors */ |
| 154 |
{ |
| 155 |
OBJECT i; |
| 156 |
OBJREC *obj; |
| 157 |
char **lp; |
| 158 |
|
| 159 |
/* Init sensor set */ |
| 160 |
photonSensorSet [0] = 0; |
| 161 |
|
| 162 |
if (!sensorList [0]) |
| 163 |
return; |
| 164 |
|
| 165 |
for (i = 0; i < nobjects; i++) { |
| 166 |
obj = objptr(i); |
| 167 |
|
| 168 |
/* Insert object in sensor set if it's in the specified sensor list |
| 169 |
* and of type antimatter */ |
| 170 |
for (lp = sensorList; *lp; lp++) { |
| 171 |
if (!strcmp(obj -> oname, *lp)) { |
| 172 |
if (obj -> otype != MAT_CLIP) { |
| 173 |
sprintf(errmsg, "photon sensor modifier %s is not antimatter", |
| 174 |
obj -> oname); |
| 175 |
error(USER, errmsg); |
| 176 |
} |
| 177 |
|
| 178 |
if (photonSensorSet [0] >= AMBLLEN) |
| 179 |
error(USER, "too many photon sensor modifiers"); |
| 180 |
|
| 181 |
insertelem(photonSensorSet, i); |
| 182 |
} |
| 183 |
} |
| 184 |
} |
| 185 |
|
| 186 |
if (!photonSensorSet [0]) |
| 187 |
error(USER, "no photon sensors found"); |
| 188 |
} |
| 189 |
|
| 190 |
|
| 191 |
|
| 192 |
/* ================ Material specific scattering routines ================ */ |
| 193 |
|
| 194 |
|
| 195 |
static int isoSpecPhotonScatter (NORMDAT *nd, RAY *rayOut) |
| 196 |
/* Generate direction for isotropically specularly reflected |
| 197 |
or transmitted ray. Returns 1 if successful. */ |
| 198 |
{ |
| 199 |
FVECT u, v, h; |
| 200 |
RAY *rayIn = nd -> rp; |
| 201 |
double d, d2, sinp, cosp; |
| 202 |
int niter, i = 0; |
| 203 |
|
| 204 |
/* Set up sample coordinates */ |
| 205 |
getperpendicular(u, nd -> pnorm, 1); |
| 206 |
fcross(v, nd -> pnorm, u); |
| 207 |
|
| 208 |
if (nd -> specfl & SP_REFL) { |
| 209 |
/* Specular reflection; make MAXITER attempts at getting a ray */ |
| 210 |
|
| 211 |
for (niter = 0; niter < MAXITER; niter++) { |
| 212 |
d = 2 * PI * pmapRandom(scatterState); |
| 213 |
cosp = cos(d); |
| 214 |
sinp = sin(d); |
| 215 |
d2 = pmapRandom(scatterState); |
| 216 |
d = d2 <= FTINY ? 1 : sqrt(nd -> alpha2 * -log(d2)); |
| 217 |
|
| 218 |
for (i = 0; i < 3; i++) |
| 219 |
h [i] = nd -> pnorm [i] + d * (cosp * u [i] + sinp * v [i]); |
| 220 |
|
| 221 |
d = -2 * DOT(h, rayIn -> rdir) / (1 + d * d); |
| 222 |
VSUM(rayOut -> rdir, rayIn -> rdir, h, d); |
| 223 |
|
| 224 |
if (DOT(rayOut -> rdir, rayIn -> ron) > FTINY) |
| 225 |
return 1; |
| 226 |
} |
| 227 |
|
| 228 |
return 0; |
| 229 |
} |
| 230 |
|
| 231 |
else { |
| 232 |
/* Specular transmission; make MAXITER attempts at getting a ray */ |
| 233 |
|
| 234 |
for (niter = 0; niter < MAXITER; niter++) { |
| 235 |
d = 2 * PI * pmapRandom(scatterState); |
| 236 |
cosp = cos(d); |
| 237 |
sinp = sin(d); |
| 238 |
d2 = pmapRandom(scatterState); |
| 239 |
d = d2 <= FTINY ? 1 : sqrt(-log(d2) * nd -> alpha2); |
| 240 |
|
| 241 |
for (i = 0; i < 3; i++) |
| 242 |
rayOut -> rdir [i] = nd -> prdir [i] + |
| 243 |
d * (cosp * u [i] + sinp * v [i]); |
| 244 |
|
| 245 |
if (DOT(rayOut -> rdir, rayIn -> ron) < -FTINY) { |
| 246 |
normalize(rayOut -> rdir); |
| 247 |
return 1; |
| 248 |
} |
| 249 |
} |
| 250 |
|
| 251 |
return 0; |
| 252 |
} |
| 253 |
} |
| 254 |
|
| 255 |
|
| 256 |
|
| 257 |
static void diffPhotonScatter (FVECT normal, RAY* rayOut) |
| 258 |
/* Generate cosine-weighted direction for diffuse ray */ |
| 259 |
{ |
| 260 |
const RREAL cosThetaSqr = pmapRandom(scatterState), |
| 261 |
cosTheta = sqrt(cosThetaSqr), |
| 262 |
sinTheta = sqrt(1 - cosThetaSqr), |
| 263 |
phi = 2 * PI * pmapRandom(scatterState), |
| 264 |
du = cos(phi) * sinTheta, dv = sin(phi) * sinTheta; |
| 265 |
FVECT u, v; |
| 266 |
int i = 0; |
| 267 |
|
| 268 |
/* Set up sample coordinates */ |
| 269 |
getperpendicular(u, normal, 1); |
| 270 |
fcross(v, normal, u); |
| 271 |
|
| 272 |
/* Convert theta & phi to cartesian */ |
| 273 |
for (i = 0; i < 3; i++) |
| 274 |
rayOut -> rdir [i] = du * u [i] + dv * v [i] + cosTheta * normal [i]; |
| 275 |
|
| 276 |
normalize(rayOut -> rdir); |
| 277 |
} |
| 278 |
|
| 279 |
|
| 280 |
|
| 281 |
static int normalPhotonScatter (OBJREC *mat, RAY *rayIn) |
| 282 |
/* Generate new photon ray for isotropic material and recurse */ |
| 283 |
{ |
| 284 |
NORMDAT nd; |
| 285 |
int i, hastexture; |
| 286 |
float xi, albedo, prdiff, ptdiff, prspec, ptspec; |
| 287 |
double d, fresnel; |
| 288 |
RAY rayOut; |
| 289 |
|
| 290 |
if (mat -> oargs.nfargs != (mat -> otype == MAT_TRANS ? 7 : 5)) |
| 291 |
objerror(mat, USER, "bad number of arguments"); |
| 292 |
|
| 293 |
/* Check for back side; reorient if back is visible */ |
| 294 |
if (rayIn -> rod < 0) |
| 295 |
if (!backvis && mat -> otype != MAT_TRANS) |
| 296 |
return 0; |
| 297 |
else { |
| 298 |
/* Get modifiers */ |
| 299 |
raytexture(rayIn, mat -> omod); |
| 300 |
flipsurface(rayIn); |
| 301 |
} |
| 302 |
else raytexture(rayIn, mat -> omod); |
| 303 |
|
| 304 |
nd.rp = rayIn; |
| 305 |
|
| 306 |
/* Get material color */ |
| 307 |
copycolor(nd.mcolor, mat -> oargs.farg); |
| 308 |
|
| 309 |
/* Get roughness */ |
| 310 |
nd.specfl = 0; |
| 311 |
nd.alpha2 = mat -> oargs.farg [4]; |
| 312 |
|
| 313 |
if ((nd.alpha2 *= nd.alpha2) <= FTINY) |
| 314 |
nd.specfl |= SP_PURE; |
| 315 |
|
| 316 |
if (rayIn -> ro != NULL && isflat(rayIn -> ro -> otype)) |
| 317 |
nd.specfl |= SP_FLAT; |
| 318 |
|
| 319 |
/* Perturb normal */ |
| 320 |
if ((hastexture = (DOT(rayIn -> pert, rayIn -> pert) > sqr(FTINY)) )) |
| 321 |
nd.pdot = raynormal(nd.pnorm, rayIn); |
| 322 |
else { |
| 323 |
VCOPY(nd.pnorm, rayIn -> ron); |
| 324 |
nd.pdot = rayIn -> rod; |
| 325 |
} |
| 326 |
|
| 327 |
nd.pdot = max(nd.pdot, .001); |
| 328 |
|
| 329 |
/* Modify material color */ |
| 330 |
multcolor(nd.mcolor, rayIn -> pcol); |
| 331 |
nd.rspec = mat -> oargs.farg [3]; |
| 332 |
|
| 333 |
/* Approximate Fresnel term */ |
| 334 |
if (nd.specfl & SP_PURE && nd.rspec > FTINY) { |
| 335 |
fresnel = FRESNE(rayIn -> rod); |
| 336 |
nd.rspec += fresnel * (1 - nd.rspec); |
| 337 |
} |
| 338 |
else fresnel = 0; |
| 339 |
|
| 340 |
/* Transmission params */ |
| 341 |
if (mat -> otype == MAT_TRANS) { |
| 342 |
nd.trans = mat -> oargs.farg [5] * (1 - nd.rspec); |
| 343 |
nd.tspec = nd.trans * mat -> oargs.farg [6]; |
| 344 |
nd.tdiff = nd.trans - nd.tspec; |
| 345 |
} |
| 346 |
else nd.tdiff = nd.tspec = nd.trans = 0; |
| 347 |
|
| 348 |
/* Specular reflection params */ |
| 349 |
if (nd.rspec > FTINY) { |
| 350 |
/* Specular color */ |
| 351 |
if (mat -> otype != MAT_METAL) |
| 352 |
setcolor(nd.scolor, nd.rspec, nd.rspec, nd.rspec); |
| 353 |
else if (fresnel > FTINY) { |
| 354 |
d = nd.rspec * (1 - fresnel); |
| 355 |
for (i = 0; i < 3; i++) |
| 356 |
nd.scolor [i] = fresnel + nd.mcolor [i] * d; |
| 357 |
} |
| 358 |
else { |
| 359 |
copycolor(nd.scolor, nd.mcolor); |
| 360 |
scalecolor(nd.scolor, nd.rspec); |
| 361 |
} |
| 362 |
} |
| 363 |
else setcolor(nd.scolor, 0, 0, 0); |
| 364 |
|
| 365 |
/* Diffuse reflection params */ |
| 366 |
nd.rdiff = 1 - nd.trans - nd.rspec; |
| 367 |
|
| 368 |
/* Set up probabilities */ |
| 369 |
prdiff = ptdiff = ptspec = colorAvg(nd.mcolor); |
| 370 |
prdiff *= nd.rdiff; |
| 371 |
ptdiff *= nd.tdiff; |
| 372 |
prspec = colorAvg(nd.scolor); |
| 373 |
ptspec *= nd.tspec; |
| 374 |
albedo = prdiff + ptdiff + prspec + ptspec; |
| 375 |
|
| 376 |
/* Insert direct and indirect photon hits if diffuse component */ |
| 377 |
if (prdiff > FTINY || ptdiff > FTINY) |
| 378 |
addPhotons(rayIn); |
| 379 |
|
| 380 |
xi = pmapRandom(rouletteState); |
| 381 |
|
| 382 |
if (xi > albedo) |
| 383 |
/* Absorbed */ |
| 384 |
return 0; |
| 385 |
|
| 386 |
if (xi > (albedo -= prspec)) { |
| 387 |
/* Specular reflection */ |
| 388 |
nd.specfl |= SP_REFL; |
| 389 |
|
| 390 |
if (nd.specfl & SP_PURE) { |
| 391 |
/* Perfect specular reflection */ |
| 392 |
for (i = 0; i < 3; i++) { |
| 393 |
/* Reflected ray */ |
| 394 |
nd.vrefl [i] = rayIn -> rdir [i] + 2 * nd.pdot * nd.pnorm [i]; |
| 395 |
} |
| 396 |
|
| 397 |
/* Penetration? */ |
| 398 |
if (hastexture && DOT(nd.vrefl, rayIn -> ron) <= FTINY) |
| 399 |
for (i = 0; i < 3; i++) { |
| 400 |
/* Safety measure */ |
| 401 |
nd.vrefl [i] = rayIn -> rdir [i] + |
| 402 |
2 * rayIn -> rod * rayIn -> ron [i]; |
| 403 |
} |
| 404 |
|
| 405 |
VCOPY(rayOut.rdir, nd.vrefl); |
| 406 |
} |
| 407 |
|
| 408 |
else if (!isoSpecPhotonScatter(&nd, &rayOut)) |
| 409 |
return 0; |
| 410 |
|
| 411 |
photonRay(rayIn, &rayOut, PMAP_SPECREFL, nd.scolor); |
| 412 |
} |
| 413 |
|
| 414 |
else if (xi > (albedo -= ptspec)) { |
| 415 |
/* Specular transmission */ |
| 416 |
nd.specfl |= SP_TRAN; |
| 417 |
|
| 418 |
if (hastexture) { |
| 419 |
/* Perturb */ |
| 420 |
for (i = 0; i < 3; i++) |
| 421 |
nd.prdir [i] = rayIn -> rdir [i] - rayIn -> pert [i]; |
| 422 |
|
| 423 |
if (DOT(nd.prdir, rayIn -> ron) < -FTINY) |
| 424 |
normalize(nd.prdir); |
| 425 |
else VCOPY(nd.prdir, rayIn -> rdir); |
| 426 |
} |
| 427 |
else VCOPY(nd.prdir, rayIn -> rdir); |
| 428 |
|
| 429 |
if ((nd.specfl & (SP_TRAN | SP_PURE)) == (SP_TRAN | SP_PURE)) |
| 430 |
/* Perfect specular transmission */ |
| 431 |
VCOPY(rayOut.rdir, nd.prdir); |
| 432 |
else if (!isoSpecPhotonScatter(&nd, &rayOut)) |
| 433 |
return 0; |
| 434 |
|
| 435 |
photonRay(rayIn, &rayOut, PMAP_SPECTRANS, nd.mcolor); |
| 436 |
} |
| 437 |
|
| 438 |
else if (xi > (albedo -= prdiff)) { |
| 439 |
/* Diffuse reflection */ |
| 440 |
photonRay(rayIn, &rayOut, PMAP_DIFFREFL, nd.mcolor); |
| 441 |
diffPhotonScatter(hastexture ? nd.pnorm : rayIn -> ron, &rayOut); |
| 442 |
} |
| 443 |
|
| 444 |
else { |
| 445 |
/* Diffuse transmission */ |
| 446 |
flipsurface(rayIn); |
| 447 |
photonRay(rayIn, &rayOut, PMAP_DIFFTRANS, nd.mcolor); |
| 448 |
|
| 449 |
if (hastexture) { |
| 450 |
FVECT bnorm; |
| 451 |
bnorm [0] = -nd.pnorm [0]; |
| 452 |
bnorm [1] = -nd.pnorm [1]; |
| 453 |
bnorm [2] = -nd.pnorm [2]; |
| 454 |
diffPhotonScatter(bnorm, &rayOut); |
| 455 |
} |
| 456 |
else diffPhotonScatter(rayIn -> ron, &rayOut); |
| 457 |
} |
| 458 |
|
| 459 |
tracePhoton(&rayOut); |
| 460 |
return 0; |
| 461 |
} |
| 462 |
|
| 463 |
|
| 464 |
|
| 465 |
static void getacoords (ANISODAT *np) |
| 466 |
/* Set up coordinate system for anisotropic sampling; cloned from aniso.c */ |
| 467 |
{ |
| 468 |
MFUNC *mf; |
| 469 |
int i; |
| 470 |
|
| 471 |
mf = getfunc(np->mp, 3, 0x7, 1); |
| 472 |
setfunc(np->mp, np->rp); |
| 473 |
errno = 0; |
| 474 |
|
| 475 |
for (i = 0; i < 3; i++) |
| 476 |
np->u[i] = evalue(mf->ep[i]); |
| 477 |
|
| 478 |
if ((errno == EDOM) | (errno == ERANGE)) { |
| 479 |
objerror(np->mp, WARNING, "compute error"); |
| 480 |
np->specfl |= SP_BADU; |
| 481 |
return; |
| 482 |
} |
| 483 |
|
| 484 |
if (mf->fxp != &unitxf) |
| 485 |
multv3(np->u, np->u, mf->fxp->xfm); |
| 486 |
|
| 487 |
fcross(np->v, np->pnorm, np->u); |
| 488 |
|
| 489 |
if (normalize(np->v) == 0.0) { |
| 490 |
objerror(np->mp, WARNING, "illegal orientation vector"); |
| 491 |
np->specfl |= SP_BADU; |
| 492 |
return; |
| 493 |
} |
| 494 |
|
| 495 |
fcross(np->u, np->v, np->pnorm); |
| 496 |
} |
| 497 |
|
| 498 |
|
| 499 |
|
| 500 |
static int anisoSpecPhotonScatter (ANISODAT *nd, RAY *rayOut) |
| 501 |
/* Generate direction for anisotropically specularly reflected |
| 502 |
or transmitted ray. Returns 1 if successful. */ |
| 503 |
{ |
| 504 |
FVECT h; |
| 505 |
double d, d2, sinp, cosp; |
| 506 |
int niter, i; |
| 507 |
RAY *rayIn = nd -> rp; |
| 508 |
|
| 509 |
if (rayIn -> ro != NULL && isflat(rayIn -> ro -> otype)) |
| 510 |
nd -> specfl |= SP_FLAT; |
| 511 |
|
| 512 |
/* set up coordinates */ |
| 513 |
getacoords(nd); |
| 514 |
|
| 515 |
if (rayOut -> rtype & TRANS) { |
| 516 |
/* Specular transmission */ |
| 517 |
|
| 518 |
if (DOT(rayIn -> pert, rayIn -> pert) <= FTINY * FTINY) |
| 519 |
VCOPY(nd -> prdir, rayIn -> rdir); |
| 520 |
else { |
| 521 |
/* perturb */ |
| 522 |
for (i = 0; i < 3; i++) |
| 523 |
nd -> prdir [i] = rayIn -> rdir [i] - rayIn -> pert [i]; |
| 524 |
|
| 525 |
if (DOT(nd -> prdir, rayIn -> ron) < -FTINY) |
| 526 |
normalize(nd -> prdir); |
| 527 |
else VCOPY(nd -> prdir, rayIn -> rdir); |
| 528 |
} |
| 529 |
|
| 530 |
/* Make MAXITER attempts at getting a ray */ |
| 531 |
for (niter = 0; niter < MAXITER; niter++) { |
| 532 |
d = 2 * PI * pmapRandom(scatterState); |
| 533 |
cosp = cos(d) * nd -> u_alpha; |
| 534 |
sinp = sin(d) * nd -> v_alpha; |
| 535 |
d = sqrt(sqr(cosp) + sqr(sinp)); |
| 536 |
cosp /= d; |
| 537 |
sinp /= d; |
| 538 |
d2 = pmapRandom(scatterState); |
| 539 |
d = d2 <= FTINY ? 1 |
| 540 |
: sqrt(-log(d2) / |
| 541 |
(sqr(cosp) / sqr(nd -> u_alpha) + |
| 542 |
sqr(sinp) / (nd -> v_alpha * nd -> u_alpha))); |
| 543 |
|
| 544 |
for (i = 0; i < 3; i++) |
| 545 |
rayOut -> rdir [i] = nd -> prdir [i] + d * |
| 546 |
(cosp * nd -> u [i] + sinp * nd -> v [i]); |
| 547 |
|
| 548 |
if (DOT(rayOut -> rdir, rayIn -> ron) < -FTINY) { |
| 549 |
normalize(rayOut -> rdir); |
| 550 |
return 1; |
| 551 |
} |
| 552 |
} |
| 553 |
|
| 554 |
return 0; |
| 555 |
} |
| 556 |
|
| 557 |
else { |
| 558 |
/* Specular reflection */ |
| 559 |
|
| 560 |
/* Make MAXITER attempts at getting a ray */ |
| 561 |
for (niter = 0; niter < MAXITER; niter++) { |
| 562 |
d = 2 * PI * pmapRandom(scatterState); |
| 563 |
cosp = cos(d) * nd -> u_alpha; |
| 564 |
sinp = sin(d) * nd -> v_alpha; |
| 565 |
d = sqrt(sqr(cosp) + sqr(sinp)); |
| 566 |
cosp /= d; |
| 567 |
sinp /= d; |
| 568 |
d2 = pmapRandom(scatterState); |
| 569 |
d = d2 <= FTINY ? 1 |
| 570 |
: sqrt(-log(d2) / |
| 571 |
(sqr(cosp) / sqr(nd -> u_alpha) + |
| 572 |
sqr(sinp) / (nd -> v_alpha * nd -> v_alpha))); |
| 573 |
|
| 574 |
for (i = 0; i < 3; i++) |
| 575 |
h [i] = nd -> pnorm [i] + |
| 576 |
d * (cosp * nd -> u [i] + sinp * nd -> v [i]); |
| 577 |
|
| 578 |
d = -2 * DOT(h, rayIn -> rdir) / (1 + d * d); |
| 579 |
VSUM(rayOut -> rdir, rayIn -> rdir, h, d); |
| 580 |
|
| 581 |
if (DOT(rayOut -> rdir, rayIn -> ron) > FTINY) |
| 582 |
return 1; |
| 583 |
} |
| 584 |
|
| 585 |
return 0; |
| 586 |
} |
| 587 |
} |
| 588 |
|
| 589 |
|
| 590 |
|
| 591 |
static int anisoPhotonScatter (OBJREC *mat, RAY *rayIn) |
| 592 |
/* Generate new photon ray for anisotropic material and recurse */ |
| 593 |
{ |
| 594 |
ANISODAT nd; |
| 595 |
float xi, albedo, prdiff, ptdiff, prspec, ptspec; |
| 596 |
RAY rayOut; |
| 597 |
|
| 598 |
if (mat -> oargs.nfargs != (mat -> otype == MAT_TRANS2 ? 8 : 6)) |
| 599 |
objerror(mat, USER, "bad number of real arguments"); |
| 600 |
|
| 601 |
nd.rp = rayIn; |
| 602 |
nd.mp = objptr(rayIn -> ro -> omod); |
| 603 |
|
| 604 |
/* get material color */ |
| 605 |
copycolor(nd.mcolor, mat -> oargs.farg); |
| 606 |
|
| 607 |
/* get roughness */ |
| 608 |
nd.specfl = 0; |
| 609 |
nd.u_alpha = mat -> oargs.farg [4]; |
| 610 |
nd.v_alpha = mat -> oargs.farg [5]; |
| 611 |
if (nd.u_alpha < FTINY || nd.v_alpha <= FTINY) |
| 612 |
objerror(mat, USER, "roughness too small"); |
| 613 |
|
| 614 |
/* check for back side; reorient if back is visible */ |
| 615 |
if (rayIn -> rod < 0) |
| 616 |
if (!backvis && mat -> otype != MAT_TRANS2) |
| 617 |
return 0; |
| 618 |
else { |
| 619 |
/* get modifiers */ |
| 620 |
raytexture(rayIn, mat -> omod); |
| 621 |
flipsurface(rayIn); |
| 622 |
} |
| 623 |
else raytexture(rayIn, mat -> omod); |
| 624 |
|
| 625 |
/* perturb normal */ |
| 626 |
nd.pdot = max(raynormal(nd.pnorm, rayIn), .001); |
| 627 |
|
| 628 |
/* modify material color */ |
| 629 |
multcolor(nd.mcolor, rayIn -> pcol); |
| 630 |
nd.rspec = mat -> oargs.farg [3]; |
| 631 |
|
| 632 |
/* transmission params */ |
| 633 |
if (mat -> otype == MAT_TRANS2) { |
| 634 |
nd.trans = mat -> oargs.farg [6] * (1 - nd.rspec); |
| 635 |
nd.tspec = nd.trans * mat -> oargs.farg [7]; |
| 636 |
nd.tdiff = nd.trans - nd.tspec; |
| 637 |
if (nd.tspec > FTINY) |
| 638 |
nd.specfl |= SP_TRAN; |
| 639 |
} |
| 640 |
else nd.tdiff = nd.tspec = nd.trans = 0; |
| 641 |
|
| 642 |
/* specular reflection params */ |
| 643 |
if (nd.rspec > FTINY) { |
| 644 |
nd.specfl |= SP_REFL; |
| 645 |
|
| 646 |
/* comput e specular color */ |
| 647 |
if (mat -> otype == MAT_METAL2) |
| 648 |
copycolor(nd.scolor, nd.mcolor); |
| 649 |
else setcolor(nd.scolor, 1, 1, 1); |
| 650 |
|
| 651 |
scalecolor(nd.scolor, nd.rspec); |
| 652 |
} |
| 653 |
else setcolor(nd.scolor, 0, 0, 0); |
| 654 |
|
| 655 |
/* diffuse reflection params */ |
| 656 |
nd.rdiff = 1 - nd.trans - nd.rspec; |
| 657 |
|
| 658 |
/* Set up probabilities */ |
| 659 |
prdiff = ptdiff = ptspec = colorAvg(nd.mcolor); |
| 660 |
prdiff *= nd.rdiff; |
| 661 |
ptdiff *= nd.tdiff; |
| 662 |
prspec = colorAvg(nd.scolor); |
| 663 |
ptspec *= nd.tspec; |
| 664 |
albedo = prdiff + ptdiff + prspec + ptspec; |
| 665 |
|
| 666 |
/* Insert direct and indirect photon hits if diffuse component */ |
| 667 |
if (prdiff > FTINY || ptdiff > FTINY) |
| 668 |
addPhotons(rayIn); |
| 669 |
|
| 670 |
xi = pmapRandom(rouletteState); |
| 671 |
|
| 672 |
if (xi > albedo) |
| 673 |
/* Absorbed */ |
| 674 |
return 0; |
| 675 |
|
| 676 |
if (xi > (albedo -= prspec)) |
| 677 |
/* Specular reflection */ |
| 678 |
if (!(nd.specfl & SP_BADU)) { |
| 679 |
photonRay(rayIn, &rayOut, PMAP_SPECREFL, nd.scolor); |
| 680 |
|
| 681 |
if (!anisoSpecPhotonScatter(&nd, &rayOut)) |
| 682 |
return 0; |
| 683 |
} |
| 684 |
else return 0; |
| 685 |
|
| 686 |
else if (xi > (albedo -= ptspec)) |
| 687 |
/* Specular transmission */ |
| 688 |
|
| 689 |
if (!(nd.specfl & SP_BADU)) { |
| 690 |
/* Specular transmission */ |
| 691 |
photonRay(rayIn, &rayOut, PMAP_SPECTRANS, nd.mcolor); |
| 692 |
|
| 693 |
if (!anisoSpecPhotonScatter(&nd, &rayOut)) |
| 694 |
return 0; |
| 695 |
} |
| 696 |
else return 0; |
| 697 |
|
| 698 |
else if (xi > (albedo -= prdiff)) { |
| 699 |
/* Diffuse reflection */ |
| 700 |
photonRay(rayIn, &rayOut, PMAP_DIFFREFL, nd.mcolor); |
| 701 |
diffPhotonScatter(nd.pnorm, &rayOut); |
| 702 |
} |
| 703 |
|
| 704 |
else { |
| 705 |
/* Diffuse transmission */ |
| 706 |
FVECT bnorm; |
| 707 |
flipsurface(rayIn); |
| 708 |
bnorm [0] = -nd.pnorm [0]; |
| 709 |
bnorm [1] = -nd.pnorm [1]; |
| 710 |
bnorm [2] = -nd.pnorm [2]; |
| 711 |
|
| 712 |
photonRay(rayIn, &rayOut, PMAP_DIFFTRANS, nd.mcolor); |
| 713 |
diffPhotonScatter(bnorm, &rayOut); |
| 714 |
} |
| 715 |
|
| 716 |
tracePhoton(&rayOut); |
| 717 |
return 0; |
| 718 |
} |
| 719 |
|
| 720 |
|
| 721 |
static double mylog (double x) |
| 722 |
/* special log for extinction coefficients; cloned from dielectric.c */ |
| 723 |
{ |
| 724 |
if (x < 1e-40) |
| 725 |
return(-100.); |
| 726 |
|
| 727 |
if (x >= 1.) |
| 728 |
return(0.); |
| 729 |
|
| 730 |
return(log(x)); |
| 731 |
} |
| 732 |
|
| 733 |
|
| 734 |
static int dielectricPhotonScatter (OBJREC *mat, RAY *rayIn) |
| 735 |
/* Generate new photon ray for dielectric material and recurse */ |
| 736 |
{ |
| 737 |
double cos1, cos2, nratio, d1, d2, refl; |
| 738 |
COLOR ctrans, talb; |
| 739 |
FVECT dnorm; |
| 740 |
int hastexture, i; |
| 741 |
RAY rayOut; |
| 742 |
|
| 743 |
if (mat -> oargs.nfargs != (mat -> otype == MAT_DIELECTRIC ? 5 : 8)) |
| 744 |
objerror(mat, USER, "bad arguments"); |
| 745 |
|
| 746 |
/* get modifiers */ |
| 747 |
raytexture(rayIn, mat -> omod); |
| 748 |
|
| 749 |
if ((hastexture = (DOT(rayIn -> pert, rayIn -> pert) > FTINY * FTINY))) |
| 750 |
/* Perturb normal */ |
| 751 |
cos1 = raynormal(dnorm, rayIn); |
| 752 |
else { |
| 753 |
VCOPY(dnorm, rayIn -> ron); |
| 754 |
cos1 = rayIn -> rod; |
| 755 |
} |
| 756 |
|
| 757 |
/* index of refraction */ |
| 758 |
nratio = mat -> otype == |
| 759 |
MAT_DIELECTRIC ? mat -> oargs.farg [3] + mat -> oargs.farg [4] / MLAMBDA |
| 760 |
: mat -> oargs.farg [3] / mat -> oargs.farg [7]; |
| 761 |
|
| 762 |
if (cos1 < 0) { |
| 763 |
/* inside */ |
| 764 |
hastexture = -hastexture; |
| 765 |
cos1 = -cos1; |
| 766 |
dnorm [0] = -dnorm [0]; |
| 767 |
dnorm [1] = -dnorm [1]; |
| 768 |
dnorm [2] = -dnorm [2]; |
| 769 |
setcolor(rayIn -> cext, |
| 770 |
-mylog(mat -> oargs.farg [0] * rayIn -> pcol [0]), |
| 771 |
-mylog(mat -> oargs.farg [1] * rayIn -> pcol [1]), |
| 772 |
-mylog(mat -> oargs.farg [2] * rayIn -> pcol [2])); |
| 773 |
setcolor(rayIn -> albedo, 0, 0, 0); |
| 774 |
rayIn -> gecc = 0; |
| 775 |
|
| 776 |
if (mat -> otype == MAT_INTERFACE) { |
| 777 |
setcolor(ctrans, |
| 778 |
-mylog(mat -> oargs.farg [4] * rayIn -> pcol [0]), |
| 779 |
-mylog(mat -> oargs.farg [5] * rayIn -> pcol [1]), |
| 780 |
-mylog(mat -> oargs.farg [6] * rayIn -> pcol [2])); |
| 781 |
setcolor(talb, 0, 0, 0); |
| 782 |
} |
| 783 |
else { |
| 784 |
copycolor(ctrans, cextinction); |
| 785 |
copycolor(talb, salbedo); |
| 786 |
} |
| 787 |
} |
| 788 |
|
| 789 |
else { |
| 790 |
/* outside */ |
| 791 |
nratio = 1.0 / nratio; |
| 792 |
setcolor(ctrans, |
| 793 |
-mylog(mat -> oargs.farg [0] * rayIn -> pcol [0]), |
| 794 |
-mylog(mat -> oargs.farg [1] * rayIn -> pcol [1]), |
| 795 |
-mylog(mat -> oargs.farg [2] * rayIn -> pcol [2])); |
| 796 |
setcolor(talb, 0, 0, 0); |
| 797 |
|
| 798 |
if (mat -> otype == MAT_INTERFACE) { |
| 799 |
setcolor(rayIn -> cext, |
| 800 |
-mylog(mat -> oargs.farg [4] * rayIn -> pcol [0]), |
| 801 |
-mylog(mat -> oargs.farg [5] * rayIn -> pcol [1]), |
| 802 |
-mylog(mat -> oargs.farg [6] * rayIn -> pcol [2])); |
| 803 |
setcolor(rayIn -> albedo, 0, 0, 0); |
| 804 |
rayIn -> gecc = 0; |
| 805 |
} |
| 806 |
} |
| 807 |
|
| 808 |
/* compute cos theta2 */ |
| 809 |
d2 = 1 - sqr(nratio) * (1 - sqr(cos1)); |
| 810 |
|
| 811 |
if (d2 < FTINY) { |
| 812 |
/* Total reflection */ |
| 813 |
refl = cos2 = 1.0; |
| 814 |
} |
| 815 |
else { |
| 816 |
/* Refraction, compute Fresnel's equations */ |
| 817 |
cos2 = sqrt(d2); |
| 818 |
d1 = cos1; |
| 819 |
d2 = nratio * cos2; |
| 820 |
d1 = (d1 - d2) / (d1 + d2); |
| 821 |
refl = sqr(d1); |
| 822 |
d1 = 1 / cos1; |
| 823 |
d2 = nratio / cos2; |
| 824 |
d1 = (d1 - d2) / (d1 + d2); |
| 825 |
refl += sqr(d1); |
| 826 |
refl *= 0.5; |
| 827 |
} |
| 828 |
|
| 829 |
if (pmapRandom(rouletteState) > refl) { |
| 830 |
/* Refraction */ |
| 831 |
photonRay(rayIn, &rayOut, PMAP_REFRACT, NULL); |
| 832 |
d1 = nratio * cos1 - cos2; |
| 833 |
|
| 834 |
for (i = 0; i < 3; i++) |
| 835 |
rayOut.rdir [i] = nratio * rayIn -> rdir [i] + d1 * dnorm [i]; |
| 836 |
|
| 837 |
if (hastexture && DOT(rayOut.rdir, rayIn -> ron) * hastexture >= -FTINY) { |
| 838 |
d1 *= hastexture; |
| 839 |
|
| 840 |
for (i = 0; i < 3; i++) |
| 841 |
rayOut.rdir [i] = nratio * rayIn -> rdir [i] + |
| 842 |
d1 * rayIn -> ron [i]; |
| 843 |
|
| 844 |
normalize(rayOut.rdir); |
| 845 |
} |
| 846 |
|
| 847 |
copycolor(rayOut.cext, ctrans); |
| 848 |
copycolor(rayOut.albedo, talb); |
| 849 |
} |
| 850 |
|
| 851 |
else { |
| 852 |
/* Reflection */ |
| 853 |
photonRay(rayIn, &rayOut, PMAP_SPECREFL, NULL); |
| 854 |
VSUM(rayOut.rdir, rayIn -> rdir, dnorm, 2 * cos1); |
| 855 |
|
| 856 |
if (hastexture && DOT(rayOut.rdir, rayIn -> ron) * hastexture <= FTINY) |
| 857 |
for (i = 0; i < 3; i++) |
| 858 |
rayOut.rdir [i] = rayIn -> rdir [i] + |
| 859 |
2 * rayIn -> rod * rayIn -> ron [i]; |
| 860 |
} |
| 861 |
|
| 862 |
/* Ray is modified by medium defined by cext and albedo in |
| 863 |
* photonParticipate() */ |
| 864 |
tracePhoton(&rayOut); |
| 865 |
|
| 866 |
return 0; |
| 867 |
} |
| 868 |
|
| 869 |
|
| 870 |
|
| 871 |
static int glassPhotonScatter (OBJREC *mat, RAY *rayIn) |
| 872 |
/* Generate new photon ray for glass material and recurse */ |
| 873 |
{ |
| 874 |
float albedo, xi, ptrans; |
| 875 |
COLOR mcolor, refl, trans; |
| 876 |
double pdot, cos2, d, r1e, r1m, rindex = 0.0; |
| 877 |
FVECT pnorm, pdir; |
| 878 |
int hastexture, i; |
| 879 |
RAY rayOut; |
| 880 |
|
| 881 |
/* check arguments */ |
| 882 |
if (mat -> oargs.nfargs == 3) |
| 883 |
rindex = RINDEX; |
| 884 |
else if (mat -> oargs.nfargs == 4) |
| 885 |
rindex = mat -> oargs.farg [3]; |
| 886 |
else objerror(mat, USER, "bad arguments"); |
| 887 |
|
| 888 |
copycolor(mcolor, mat -> oargs.farg); |
| 889 |
|
| 890 |
/* get modifiers */ |
| 891 |
raytexture(rayIn, mat -> omod); |
| 892 |
|
| 893 |
/* reorient if necessary */ |
| 894 |
if (rayIn -> rod < 0) |
| 895 |
flipsurface(rayIn); |
| 896 |
if ((hastexture = (DOT(rayIn -> pert, rayIn -> pert) > FTINY * FTINY) )) |
| 897 |
pdot = raynormal(pnorm, rayIn); |
| 898 |
else { |
| 899 |
VCOPY(pnorm, rayIn -> ron); |
| 900 |
pdot = rayIn -> rod; |
| 901 |
} |
| 902 |
|
| 903 |
/* Modify material color */ |
| 904 |
multcolor(mcolor, rayIn -> pcol); |
| 905 |
|
| 906 |
/* angular transmission */ |
| 907 |
cos2 = sqrt((1 - 1 / sqr(rindex)) + sqr(pdot / rindex)); |
| 908 |
setcolor(mcolor, pow(mcolor [0], 1 / cos2), pow(mcolor [1], 1 / cos2), |
| 909 |
pow(mcolor [2], 1 / cos2)); |
| 910 |
|
| 911 |
/* compute reflection */ |
| 912 |
r1e = (pdot - rindex * cos2) / (pdot + rindex * cos2); |
| 913 |
r1e *= r1e; |
| 914 |
r1m = (1 / pdot - rindex / cos2) / (1 / pdot + rindex / cos2); |
| 915 |
r1m *= r1m; |
| 916 |
|
| 917 |
for (i = 0; i < 3; i++) { |
| 918 |
double r1ed2, r1md2, d2; |
| 919 |
|
| 920 |
d = mcolor [i]; |
| 921 |
d2 = sqr(d); |
| 922 |
r1ed2 = sqr(r1e) * d2; |
| 923 |
r1md2 = sqr(r1m) * d2; |
| 924 |
|
| 925 |
/* compute transmittance */ |
| 926 |
trans [i] = 0.5 * d * |
| 927 |
(sqr(1 - r1e) / (1 - r1ed2) + sqr(1 - r1m) / (1 - r1md2)); |
| 928 |
|
| 929 |
/* compute reflectance */ |
| 930 |
refl [i] = 0.5 * (r1e * (1 + (1 - 2 * r1e) * d2) / (1 - r1ed2) + |
| 931 |
r1m * (1 + (1 - 2 * r1m) * d2) / (1 - r1md2)); |
| 932 |
} |
| 933 |
|
| 934 |
/* Set up probabilities */ |
| 935 |
ptrans = colorAvg(trans); |
| 936 |
albedo = colorAvg(refl) + ptrans; |
| 937 |
xi = pmapRandom(rouletteState); |
| 938 |
|
| 939 |
|
| 940 |
if (xi > albedo) |
| 941 |
/* Absorbed */ |
| 942 |
return 0; |
| 943 |
|
| 944 |
if (xi > (albedo -= ptrans)) { |
| 945 |
/* Transmitted */ |
| 946 |
|
| 947 |
if (hastexture) { |
| 948 |
/* perturb direction */ |
| 949 |
VSUM(pdir, rayIn -> rdir, rayIn -> pert, 2 * (1 - rindex)); |
| 950 |
|
| 951 |
if (normalize(pdir) == 0) { |
| 952 |
objerror(mat, WARNING, "bad perturbation"); |
| 953 |
VCOPY(pdir, rayIn -> rdir); |
| 954 |
} |
| 955 |
} |
| 956 |
else VCOPY(pdir, rayIn -> rdir); |
| 957 |
|
| 958 |
VCOPY(rayOut.rdir, pdir); |
| 959 |
photonRay(rayIn, &rayOut, PMAP_SPECTRANS, mcolor); |
| 960 |
} |
| 961 |
|
| 962 |
else { |
| 963 |
/* reflected ray */ |
| 964 |
VSUM(rayOut.rdir, rayIn -> rdir, pnorm, 2 * pdot); |
| 965 |
photonRay(rayIn, &rayOut, PMAP_SPECREFL, mcolor); |
| 966 |
} |
| 967 |
|
| 968 |
tracePhoton(&rayOut); |
| 969 |
return 0; |
| 970 |
} |
| 971 |
|
| 972 |
|
| 973 |
|
| 974 |
static int aliasPhotonScatter (OBJREC *mat, RAY *rayIn) |
| 975 |
/* Transfer photon scattering to alias target */ |
| 976 |
{ |
| 977 |
OBJECT aliasObj; |
| 978 |
OBJREC aliasRec; |
| 979 |
|
| 980 |
/* Straight replacement? */ |
| 981 |
if (!mat -> oargs.nsargs) { |
| 982 |
mat = objptr(mat -> omod); |
| 983 |
photonScatter [mat -> otype] (mat, rayIn); |
| 984 |
|
| 985 |
return 0; |
| 986 |
} |
| 987 |
|
| 988 |
/* Else replace alias */ |
| 989 |
if (mat -> oargs.nsargs != 1) |
| 990 |
objerror(mat, INTERNAL, "bad # string arguments"); |
| 991 |
|
| 992 |
aliasObj = lastmod(objndx(mat), mat -> oargs.sarg [0]); |
| 993 |
|
| 994 |
if (aliasObj < 0) |
| 995 |
objerror(mat, USER, "bad reference"); |
| 996 |
|
| 997 |
memcpy(&aliasRec, objptr(aliasObj), sizeof(OBJREC)); |
| 998 |
|
| 999 |
/* Substitute modifier */ |
| 1000 |
aliasRec.omod = mat -> omod; |
| 1001 |
|
| 1002 |
/* Replacement scattering routine */ |
| 1003 |
photonScatter [aliasRec.otype] (&aliasRec, rayIn); |
| 1004 |
return 0; |
| 1005 |
} |
| 1006 |
|
| 1007 |
|
| 1008 |
|
| 1009 |
static int clipPhotonScatter (OBJREC *mat, RAY *rayIn) |
| 1010 |
/* Generate new photon ray for antimatter material and recurse */ |
| 1011 |
{ |
| 1012 |
OBJECT obj = objndx(mat), mod, cset [MAXSET + 1], *modset; |
| 1013 |
int entering, inside = 0, i; |
| 1014 |
const RAY *rp; |
| 1015 |
RAY rayOut; |
| 1016 |
|
| 1017 |
if ((modset = (OBJECT*)mat -> os) == NULL) { |
| 1018 |
if (mat -> oargs.nsargs < 1 || mat -> oargs.nsargs > MAXSET) |
| 1019 |
objerror(mat, USER, "bad # arguments"); |
| 1020 |
|
| 1021 |
modset = (OBJECT*)malloc((mat -> oargs.nsargs + 1) * sizeof(OBJECT)); |
| 1022 |
|
| 1023 |
if (modset == NULL) |
| 1024 |
error(SYSTEM, "out of memory in clipPhotonScatter"); |
| 1025 |
modset [0] = 0; |
| 1026 |
|
| 1027 |
for (i = 0; i < mat -> oargs.nsargs; i++) { |
| 1028 |
if (!strcmp(mat -> oargs.sarg [i], VOIDID)) |
| 1029 |
continue; |
| 1030 |
|
| 1031 |
if ((mod = lastmod(obj, mat -> oargs.sarg [i])) == OVOID) { |
| 1032 |
sprintf(errmsg, "unknown modifier \"%s\"", mat -> oargs.sarg [i]); |
| 1033 |
objerror(mat, WARNING, errmsg); |
| 1034 |
continue; |
| 1035 |
} |
| 1036 |
|
| 1037 |
if (inset(modset, mod)) { |
| 1038 |
objerror(mat, WARNING, "duplicate modifier"); |
| 1039 |
continue; |
| 1040 |
} |
| 1041 |
|
| 1042 |
insertelem(modset, mod); |
| 1043 |
} |
| 1044 |
|
| 1045 |
mat -> os = (char*)modset; |
| 1046 |
} |
| 1047 |
|
| 1048 |
if (rayIn -> clipset != NULL) |
| 1049 |
setcopy(cset, rayIn -> clipset); |
| 1050 |
else cset [0] = 0; |
| 1051 |
|
| 1052 |
entering = rayIn -> rod > 0; |
| 1053 |
|
| 1054 |
/* Store photon incident from front if material defined as sensor */ |
| 1055 |
if (entering && inset(photonSensorSet, obj)) |
| 1056 |
addPhotons(rayIn); |
| 1057 |
|
| 1058 |
for (i = modset [0]; i > 0; i--) { |
| 1059 |
if (entering) { |
| 1060 |
if (!inset(cset, modset [i])) { |
| 1061 |
if (cset [0] >= MAXSET) |
| 1062 |
error(INTERNAL, "set overflow in clipPhotonScatter"); |
| 1063 |
insertelem(cset, modset [i]); |
| 1064 |
} |
| 1065 |
} |
| 1066 |
else if (inset(cset, modset [i])) |
| 1067 |
deletelem(cset, modset [i]); |
| 1068 |
} |
| 1069 |
|
| 1070 |
rayIn -> newcset = cset; |
| 1071 |
|
| 1072 |
if (strcmp(mat -> oargs.sarg [0], VOIDID)) { |
| 1073 |
for (rp = rayIn; rp -> parent != NULL; rp = rp -> parent) { |
| 1074 |
if ( !(rp -> rtype & RAYREFL) && rp->parent->ro != NULL && |
| 1075 |
inset(modset, rp -> parent -> ro -> omod)) { |
| 1076 |
|
| 1077 |
if (rp -> parent -> rod > 0) |
| 1078 |
inside++; |
| 1079 |
else inside--; |
| 1080 |
} |
| 1081 |
} |
| 1082 |
|
| 1083 |
if (inside > 0) { |
| 1084 |
flipsurface(rayIn); |
| 1085 |
mat = objptr(lastmod(obj, mat -> oargs.sarg [0])); |
| 1086 |
photonScatter [mat -> otype] (mat, rayIn); |
| 1087 |
return 0; |
| 1088 |
} |
| 1089 |
} |
| 1090 |
|
| 1091 |
/* Else transfer ray */ |
| 1092 |
photonRay(rayIn, &rayOut, PMAP_XFER, NULL); |
| 1093 |
tracePhoton(&rayOut); |
| 1094 |
|
| 1095 |
return 0; |
| 1096 |
} |
| 1097 |
|
| 1098 |
|
| 1099 |
|
| 1100 |
static int mirrorPhotonScatter (OBJREC *mat, RAY *rayIn) |
| 1101 |
/* Generate new photon ray for mirror material and recurse */ |
| 1102 |
{ |
| 1103 |
RAY rayOut; |
| 1104 |
int rpure = 1, i; |
| 1105 |
FVECT pnorm; |
| 1106 |
double pdot; |
| 1107 |
float albedo; |
| 1108 |
COLOR mcolor; |
| 1109 |
|
| 1110 |
/* check arguments */ |
| 1111 |
if (mat -> oargs.nfargs != 3 || mat -> oargs.nsargs > 1) |
| 1112 |
objerror(mat, USER, "bad number of arguments"); |
| 1113 |
|
| 1114 |
/* back is black */ |
| 1115 |
if (rayIn -> rod < 0) |
| 1116 |
return 0; |
| 1117 |
|
| 1118 |
/* get modifiers */ |
| 1119 |
raytexture(rayIn, mat -> omod); |
| 1120 |
|
| 1121 |
/* assign material color */ |
| 1122 |
copycolor(mcolor, mat -> oargs.farg); |
| 1123 |
multcolor(mcolor, rayIn -> pcol); |
| 1124 |
|
| 1125 |
/* Set up probabilities */ |
| 1126 |
albedo = colorAvg(mcolor); |
| 1127 |
|
| 1128 |
if (pmapRandom(rouletteState) > albedo) |
| 1129 |
/* Absorbed */ |
| 1130 |
return 0; |
| 1131 |
|
| 1132 |
/* compute reflected ray */ |
| 1133 |
photonRay(rayIn, &rayOut, PMAP_SPECREFL, mcolor); |
| 1134 |
|
| 1135 |
if (DOT(rayIn -> pert, rayIn -> pert) > sqr(FTINY)) { |
| 1136 |
/* use textures */ |
| 1137 |
pdot = raynormal(pnorm, rayIn); |
| 1138 |
|
| 1139 |
for (i = 0; i < 3; i++) |
| 1140 |
rayOut.rdir [i] = rayIn -> rdir [i] + 2 * pdot * pnorm [i]; |
| 1141 |
|
| 1142 |
rpure = 0; |
| 1143 |
} |
| 1144 |
|
| 1145 |
/* Check for penetration */ |
| 1146 |
if (rpure || DOT(rayOut.rdir, rayIn -> ron) <= FTINY) |
| 1147 |
for (i = 0; i < 3; i++) |
| 1148 |
rayOut.rdir [i] = rayIn -> rdir [i] + |
| 1149 |
2 * rayIn -> rod * rayIn -> ron [i]; |
| 1150 |
|
| 1151 |
tracePhoton(&rayOut); |
| 1152 |
return 0; |
| 1153 |
} |
| 1154 |
|
| 1155 |
|
| 1156 |
|
| 1157 |
static int mistPhotonScatter (OBJREC *mat, RAY *rayIn) |
| 1158 |
/* Generate new photon ray within mist and recurse */ |
| 1159 |
{ |
| 1160 |
COLOR mext; |
| 1161 |
RREAL re, ge, be; |
| 1162 |
RAY rayOut; |
| 1163 |
|
| 1164 |
/* check arguments */ |
| 1165 |
if (mat -> oargs.nfargs > 7) |
| 1166 |
objerror(mat, USER, "bad arguments"); |
| 1167 |
|
| 1168 |
if (mat -> oargs.nfargs > 2) { |
| 1169 |
/* compute extinction */ |
| 1170 |
copycolor(mext, mat -> oargs.farg); |
| 1171 |
/* get modifiers */ |
| 1172 |
raytexture(rayIn, mat -> omod); |
| 1173 |
multcolor(mext, rayIn -> pcol); |
| 1174 |
} |
| 1175 |
else setcolor(mext, 0, 0, 0); |
| 1176 |
|
| 1177 |
photonRay(rayIn, &rayOut, PMAP_XFER, NULL); |
| 1178 |
|
| 1179 |
if (rayIn -> rod > 0) { |
| 1180 |
/* entering ray */ |
| 1181 |
addcolor(rayOut.cext, mext); |
| 1182 |
|
| 1183 |
if (mat -> oargs.nfargs > 5) |
| 1184 |
copycolor(rayOut.albedo, mat -> oargs.farg + 3); |
| 1185 |
if (mat -> oargs.nfargs > 6) |
| 1186 |
rayOut.gecc = mat -> oargs.farg [6]; |
| 1187 |
} |
| 1188 |
|
| 1189 |
else { |
| 1190 |
/* leaving ray */ |
| 1191 |
re = max(rayIn -> cext [0] - mext [0], cextinction [0]); |
| 1192 |
ge = max(rayIn -> cext [1] - mext [1], cextinction [1]); |
| 1193 |
be = max(rayIn -> cext [2] - mext [2], cextinction [2]); |
| 1194 |
setcolor(rayOut.cext, re, ge, be); |
| 1195 |
|
| 1196 |
if (mat -> oargs.nfargs > 5) |
| 1197 |
copycolor(rayOut.albedo, salbedo); |
| 1198 |
if (mat -> oargs.nfargs > 6) |
| 1199 |
rayOut.gecc = seccg; |
| 1200 |
} |
| 1201 |
|
| 1202 |
tracePhoton(&rayOut); |
| 1203 |
|
| 1204 |
return 0; |
| 1205 |
} |
| 1206 |
|
| 1207 |
|
| 1208 |
|
| 1209 |
static int mx_dataPhotonScatter (OBJREC *mat, RAY *rayIn) |
| 1210 |
/* Pass photon on to materials selected by mixture data */ |
| 1211 |
{ |
| 1212 |
OBJECT obj; |
| 1213 |
double coef, pt [MAXDIM]; |
| 1214 |
DATARRAY *dp; |
| 1215 |
OBJECT mod [2]; |
| 1216 |
MFUNC *mf; |
| 1217 |
int i; |
| 1218 |
|
| 1219 |
if (mat -> oargs.nsargs < 6) |
| 1220 |
objerror(mat, USER, "bad # arguments"); |
| 1221 |
|
| 1222 |
obj = objndx(mat); |
| 1223 |
|
| 1224 |
for (i = 0; i < 2; i++) |
| 1225 |
if (!strcmp(mat -> oargs.sarg [i], VOIDID)) |
| 1226 |
mod [i] = OVOID; |
| 1227 |
else if ((mod [i] = lastmod(obj, mat -> oargs.sarg [i])) == OVOID) { |
| 1228 |
sprintf(errmsg, "undefined modifier \"%s\"", mat -> oargs.sarg [i]); |
| 1229 |
objerror(mat, USER, errmsg); |
| 1230 |
} |
| 1231 |
|
| 1232 |
dp = getdata(mat -> oargs.sarg [3]); |
| 1233 |
i = (1 << dp -> nd) - 1; |
| 1234 |
mf = getfunc(mat, 4, i << 5, 0); |
| 1235 |
setfunc(mat, rayIn); |
| 1236 |
errno = 0; |
| 1237 |
|
| 1238 |
for (i = 0; i < dp -> nd; i++) { |
| 1239 |
pt [i] = evalue(mf -> ep [i]); |
| 1240 |
|
| 1241 |
if (errno) { |
| 1242 |
objerror(mat, WARNING, "compute error"); |
| 1243 |
return 0; |
| 1244 |
} |
| 1245 |
} |
| 1246 |
|
| 1247 |
coef = datavalue(dp, pt); |
| 1248 |
errno = 0; |
| 1249 |
coef = funvalue(mat -> oargs.sarg [2], 1, &coef); |
| 1250 |
|
| 1251 |
if (errno) |
| 1252 |
objerror(mat, WARNING, "compute error"); |
| 1253 |
else { |
| 1254 |
mat = objptr(mod [pmapRandom(rouletteState) < coef ? 0 : 1]); |
| 1255 |
photonScatter [mat -> otype] (mat, rayIn); |
| 1256 |
} |
| 1257 |
|
| 1258 |
return 0; |
| 1259 |
} |
| 1260 |
|
| 1261 |
|
| 1262 |
|
| 1263 |
static int mx_pdataPhotonScatter (OBJREC *mat, RAY *rayIn) |
| 1264 |
/* Pass photon on to materials selected by mixture picture */ |
| 1265 |
{ |
| 1266 |
OBJECT obj; |
| 1267 |
double col [3], coef, pt [MAXDIM]; |
| 1268 |
DATARRAY *dp; |
| 1269 |
OBJECT mod [2]; |
| 1270 |
MFUNC *mf; |
| 1271 |
int i; |
| 1272 |
|
| 1273 |
if (mat -> oargs.nsargs < 7) |
| 1274 |
objerror(mat, USER, "bad # arguments"); |
| 1275 |
|
| 1276 |
obj = objndx(mat); |
| 1277 |
|
| 1278 |
for (i = 0; i < 2; i++) |
| 1279 |
if (!strcmp(mat -> oargs.sarg [i], VOIDID)) |
| 1280 |
mod [i] = OVOID; |
| 1281 |
else if ((mod [i] = lastmod(obj, mat -> oargs.sarg [i])) == OVOID) { |
| 1282 |
sprintf(errmsg, "undefined modifier \"%s\"", mat -> oargs.sarg [i]); |
| 1283 |
objerror(mat, USER, errmsg); |
| 1284 |
} |
| 1285 |
|
| 1286 |
dp = getpict(mat -> oargs.sarg [3]); |
| 1287 |
mf = getfunc(mat, 4, 0x3 << 5, 0); |
| 1288 |
setfunc(mat, rayIn); |
| 1289 |
errno = 0; |
| 1290 |
pt [1] = evalue(mf -> ep [0]); |
| 1291 |
pt [0] = evalue(mf -> ep [1]); |
| 1292 |
|
| 1293 |
if (errno) { |
| 1294 |
objerror(mat, WARNING, "compute error"); |
| 1295 |
return 0; |
| 1296 |
} |
| 1297 |
|
| 1298 |
for (i = 0; i < 3; i++) |
| 1299 |
col [i] = datavalue(dp + i, pt); |
| 1300 |
|
| 1301 |
errno = 0; |
| 1302 |
coef = funvalue(mat -> oargs.sarg [2], 3, col); |
| 1303 |
|
| 1304 |
if (errno) |
| 1305 |
objerror(mat, WARNING, "compute error"); |
| 1306 |
else { |
| 1307 |
mat = objptr(mod [pmapRandom(rouletteState) < coef ? 0 : 1]); |
| 1308 |
photonScatter [mat -> otype] (mat, rayIn); |
| 1309 |
} |
| 1310 |
|
| 1311 |
return 0; |
| 1312 |
} |
| 1313 |
|
| 1314 |
|
| 1315 |
|
| 1316 |
static int mx_funcPhotonScatter (OBJREC *mat, RAY *rayIn) |
| 1317 |
/* Pass photon on to materials selected by mixture function */ |
| 1318 |
{ |
| 1319 |
OBJECT obj, mod [2]; |
| 1320 |
int i; |
| 1321 |
double coef; |
| 1322 |
MFUNC *mf; |
| 1323 |
|
| 1324 |
if (mat -> oargs.nsargs < 4) |
| 1325 |
objerror(mat, USER, "bad # arguments"); |
| 1326 |
|
| 1327 |
obj = objndx(mat); |
| 1328 |
|
| 1329 |
for (i = 0; i < 2; i++) |
| 1330 |
if (!strcmp(mat -> oargs.sarg [i], VOIDID)) |
| 1331 |
mod [i] = OVOID; |
| 1332 |
else if ((mod [i] = lastmod(obj, mat -> oargs.sarg [i])) == OVOID) { |
| 1333 |
sprintf(errmsg, "undefined modifier \"%s\"", mat -> oargs.sarg [i]); |
| 1334 |
objerror(mat, USER, errmsg); |
| 1335 |
} |
| 1336 |
|
| 1337 |
mf = getfunc(mat, 3, 0x4, 0); |
| 1338 |
setfunc(mat, rayIn); |
| 1339 |
errno = 0; |
| 1340 |
|
| 1341 |
/* bound coefficient */ |
| 1342 |
coef = min(1, max(0, evalue(mf -> ep [0]))); |
| 1343 |
|
| 1344 |
if (errno) |
| 1345 |
objerror(mat, WARNING, "compute error"); |
| 1346 |
else { |
| 1347 |
mat = objptr(mod [pmapRandom(rouletteState) < coef ? 0 : 1]); |
| 1348 |
photonScatter [mat -> otype] (mat, rayIn); |
| 1349 |
} |
| 1350 |
|
| 1351 |
return 0; |
| 1352 |
} |
| 1353 |
|
| 1354 |
|
| 1355 |
|
| 1356 |
static int pattexPhotonScatter (OBJREC *mat, RAY *rayIn) |
| 1357 |
/* Generate new photon ray for pattern or texture modifier and recurse. |
| 1358 |
This code is brought to you by Henkel! :^) */ |
| 1359 |
{ |
| 1360 |
RAY rayOut; |
| 1361 |
|
| 1362 |
/* Get pattern */ |
| 1363 |
ofun [mat -> otype].funp(mat, rayIn); |
| 1364 |
if (mat -> omod != OVOID) { |
| 1365 |
/* Scatter using modifier (if any) */ |
| 1366 |
mat = objptr(mat -> omod); |
| 1367 |
photonScatter [mat -> otype] (mat, rayIn); |
| 1368 |
} |
| 1369 |
else { |
| 1370 |
/* Transfer ray if no modifier */ |
| 1371 |
photonRay(rayIn, &rayOut, PMAP_XFER, NULL); |
| 1372 |
tracePhoton(&rayOut); |
| 1373 |
} |
| 1374 |
|
| 1375 |
return 0; |
| 1376 |
} |
| 1377 |
|
| 1378 |
|
| 1379 |
|
| 1380 |
/* |
| 1381 |
================================================================== |
| 1382 |
The following code is |
| 1383 |
(c) Lucerne University of Applied Sciences and Arts, |
| 1384 |
supported by the Swiss National Science Foundation (SNSF, #147053) |
| 1385 |
================================================================== |
| 1386 |
*/ |
| 1387 |
|
| 1388 |
static int bsdfPhotonScatter (OBJREC *mat, RAY *rayIn) |
| 1389 |
/* Generate new photon ray for BSDF modifier and recurse. */ |
| 1390 |
{ |
| 1391 |
int hitFront; |
| 1392 |
SDError err; |
| 1393 |
SDValue bsdfVal; |
| 1394 |
FVECT upvec; |
| 1395 |
MFUNC *mf; |
| 1396 |
BSDFDAT nd; |
| 1397 |
RAY rayOut; |
| 1398 |
COLOR bsdfRGB; |
| 1399 |
int transmitted; |
| 1400 |
double prDiff, ptDiff, prDiffSD, ptDiffSD, prSpecSD, ptSpecSD, |
| 1401 |
albedo, xi; |
| 1402 |
const double patAlb = bright(rayIn -> pcol); |
| 1403 |
|
| 1404 |
/* Following code adapted from m_bsdf() */ |
| 1405 |
/* Check arguments */ |
| 1406 |
if (mat -> oargs.nsargs < 6 || mat -> oargs.nfargs > 9 || |
| 1407 |
mat -> oargs.nfargs % 3) |
| 1408 |
objerror(mat, USER, "bad # arguments"); |
| 1409 |
|
| 1410 |
hitFront = (rayIn -> rod > 0); |
| 1411 |
|
| 1412 |
/* Load cal file */ |
| 1413 |
mf = getfunc(mat, 5, 0x1d, 1); |
| 1414 |
|
| 1415 |
/* Get thickness */ |
| 1416 |
nd.thick = evalue(mf -> ep [0]); |
| 1417 |
if ((-FTINY <= nd.thick) & (nd.thick <= FTINY)) |
| 1418 |
nd.thick = .0; |
| 1419 |
|
| 1420 |
/* Get BSDF data */ |
| 1421 |
nd.sd = loadBSDF(mat -> oargs.sarg [1]); |
| 1422 |
|
| 1423 |
/* Extra diffuse reflectance from material def */ |
| 1424 |
if (hitFront) { |
| 1425 |
if (mat -> oargs.nfargs < 3) |
| 1426 |
setcolor(nd.rdiff, .0, .0, .0); |
| 1427 |
else setcolor(nd.rdiff, mat -> oargs.farg [0], mat -> oargs.farg [1], |
| 1428 |
mat -> oargs.farg [2]); |
| 1429 |
} |
| 1430 |
else if (mat -> oargs.nfargs < 6) { |
| 1431 |
/* Check for absorbing backside */ |
| 1432 |
if (!backvis && !nd.sd -> rb && !nd.sd -> tf) { |
| 1433 |
SDfreeCache(nd.sd); |
| 1434 |
return 0; |
| 1435 |
} |
| 1436 |
|
| 1437 |
setcolor(nd.rdiff, .0, .0, .0); |
| 1438 |
} |
| 1439 |
else setcolor(nd.rdiff, mat -> oargs.farg [3], mat -> oargs.farg [4], |
| 1440 |
mat -> oargs.farg [5]); |
| 1441 |
|
| 1442 |
/* Extra diffuse transmittance from material def */ |
| 1443 |
if (mat -> oargs.nfargs < 9) |
| 1444 |
setcolor(nd.tdiff, .0, .0, .0); |
| 1445 |
else setcolor(nd.tdiff, mat -> oargs.farg [6], mat -> oargs.farg [7], |
| 1446 |
mat -> oargs.farg [8]); |
| 1447 |
|
| 1448 |
nd.mp = mat; |
| 1449 |
nd.pr = rayIn; |
| 1450 |
|
| 1451 |
/* Get modifiers */ |
| 1452 |
raytexture(rayIn, mat -> omod); |
| 1453 |
|
| 1454 |
/* Modify diffuse values */ |
| 1455 |
multcolor(nd.rdiff, rayIn -> pcol); |
| 1456 |
multcolor(nd.tdiff, rayIn -> pcol); |
| 1457 |
|
| 1458 |
/* Get up vector & xform to world coords */ |
| 1459 |
upvec [0] = evalue(mf -> ep [1]); |
| 1460 |
upvec [1] = evalue(mf -> ep [2]); |
| 1461 |
upvec [2] = evalue(mf -> ep [3]); |
| 1462 |
|
| 1463 |
if (mf -> fxp != &unitxf) { |
| 1464 |
multv3(upvec, upvec, mf -> fxp -> xfm); |
| 1465 |
nd.thick *= mf -> fxp -> sca; |
| 1466 |
} |
| 1467 |
|
| 1468 |
if (rayIn -> rox) { |
| 1469 |
multv3(upvec, upvec, rayIn -> rox -> f.xfm); |
| 1470 |
nd.thick *= rayIn -> rox -> f.sca; |
| 1471 |
} |
| 1472 |
|
| 1473 |
/* Perturb normal */ |
| 1474 |
raynormal(nd.pnorm, rayIn); |
| 1475 |
|
| 1476 |
/* Xform incident dir to local BSDF coords */ |
| 1477 |
err = SDcompXform(nd.toloc, nd.pnorm, upvec); |
| 1478 |
|
| 1479 |
if (!err) { |
| 1480 |
nd.vray [0] = -rayIn -> rdir [0]; |
| 1481 |
nd.vray [1] = -rayIn -> rdir [1]; |
| 1482 |
nd.vray [2] = -rayIn -> rdir [2]; |
| 1483 |
err = SDmapDir(nd.vray, nd.toloc, nd.vray); |
| 1484 |
} |
| 1485 |
|
| 1486 |
if (!err) |
| 1487 |
err = SDinvXform(nd.fromloc, nd.toloc); |
| 1488 |
|
| 1489 |
if (err) { |
| 1490 |
objerror(mat, WARNING, "Illegal orientation vector"); |
| 1491 |
return 0; |
| 1492 |
} |
| 1493 |
|
| 1494 |
/* Determine BSDF resolution */ |
| 1495 |
err = SDsizeBSDF(nd.sr_vpsa, nd.vray, NULL, SDqueryMin + SDqueryMax, nd.sd); |
| 1496 |
|
| 1497 |
if (err) |
| 1498 |
objerror(mat, USER, transSDError(err)); |
| 1499 |
|
| 1500 |
nd.sr_vpsa [0] = sqrt(nd.sr_vpsa [0]); |
| 1501 |
nd.sr_vpsa [1] = sqrt(nd.sr_vpsa [1]); |
| 1502 |
|
| 1503 |
/* Orient perturbed normal towards incident side */ |
| 1504 |
if (!hitFront) { |
| 1505 |
nd.pnorm [0] = -nd.pnorm [0]; |
| 1506 |
nd.pnorm [1] = -nd.pnorm [1]; |
| 1507 |
nd.pnorm [2] = -nd.pnorm [2]; |
| 1508 |
} |
| 1509 |
|
| 1510 |
/* Get scatter probabilities (weighted by pattern except for spec refl) |
| 1511 |
* prDiff, ptDiff: extra diffuse component in material def |
| 1512 |
* prDiffSD, ptDiffSD: diffuse (constant) component in SDF |
| 1513 |
* prSpecSD, ptSpecSD: non-diffuse ("specular") component in SDF |
| 1514 |
* albedo: sum of above, inverse absorption probability */ |
| 1515 |
prDiff = colorAvg(nd.rdiff); |
| 1516 |
ptDiff = colorAvg(nd.tdiff); |
| 1517 |
prDiffSD = patAlb * SDdirectHemi(nd.vray, SDsampDf | SDsampR, nd.sd); |
| 1518 |
ptDiffSD = patAlb * SDdirectHemi(nd.vray, SDsampDf | SDsampT, nd.sd); |
| 1519 |
prSpecSD = SDdirectHemi(nd.vray, SDsampSp | SDsampR, nd.sd); |
| 1520 |
ptSpecSD = patAlb * SDdirectHemi(nd.vray, SDsampSp | SDsampT, nd.sd); |
| 1521 |
albedo = prDiff + ptDiff + prDiffSD + ptDiffSD + prSpecSD + ptSpecSD; |
| 1522 |
|
| 1523 |
/* |
| 1524 |
if (albedo > 1) |
| 1525 |
objerror(mat, WARNING, "Invalid albedo"); |
| 1526 |
*/ |
| 1527 |
|
| 1528 |
/* Insert direct and indirect photon hits if diffuse component */ |
| 1529 |
if (prDiff + ptDiff + prDiffSD + ptDiffSD > FTINY) |
| 1530 |
addPhotons(rayIn); |
| 1531 |
|
| 1532 |
xi = pmapRandom(rouletteState); |
| 1533 |
|
| 1534 |
if (xi > albedo) |
| 1535 |
/* Absorbtion */ |
| 1536 |
return 0; |
| 1537 |
|
| 1538 |
transmitted = 0; |
| 1539 |
|
| 1540 |
if ((xi -= prDiff) <= 0) { |
| 1541 |
/* Diffuse reflection (extra component in material def) */ |
| 1542 |
photonRay(rayIn, &rayOut, PMAP_DIFFREFL, nd.rdiff); |
| 1543 |
diffPhotonScatter(nd.pnorm, &rayOut); |
| 1544 |
} |
| 1545 |
|
| 1546 |
else if ((xi -= ptDiff) <= 0) { |
| 1547 |
/* Diffuse transmission (extra component in material def) */ |
| 1548 |
flipsurface(rayIn); |
| 1549 |
nd.thick = -nd.thick; |
| 1550 |
photonRay(rayIn, &rayOut, PMAP_DIFFTRANS, nd.tdiff); |
| 1551 |
diffPhotonScatter(nd.pnorm, &rayOut); |
| 1552 |
transmitted = 1; |
| 1553 |
} |
| 1554 |
|
| 1555 |
else { /* Sample SDF */ |
| 1556 |
if ((xi -= prDiffSD) <= 0) { |
| 1557 |
/* Diffuse SDF reflection (constant component) */ |
| 1558 |
if ((err = SDsampBSDF(&bsdfVal, nd.vray, pmapRandom(scatterState), |
| 1559 |
SDsampDf | SDsampR, nd.sd))) |
| 1560 |
objerror(mat, USER, transSDError(err)); |
| 1561 |
|
| 1562 |
/* Apply pattern to spectral component */ |
| 1563 |
ccy2rgb(&bsdfVal.spec, bsdfVal.cieY, bsdfRGB); |
| 1564 |
multcolor(bsdfRGB, rayIn -> pcol); |
| 1565 |
photonRay(rayIn, &rayOut, PMAP_DIFFREFL, bsdfRGB); |
| 1566 |
} |
| 1567 |
|
| 1568 |
else if ((xi -= ptDiffSD) <= 0) { |
| 1569 |
/* Diffuse SDF transmission (constant component) */ |
| 1570 |
if ((err = SDsampBSDF(&bsdfVal, nd.vray, pmapRandom(scatterState), |
| 1571 |
SDsampDf | SDsampT, nd.sd))) |
| 1572 |
objerror(mat, USER, transSDError(err)); |
| 1573 |
|
| 1574 |
/* Apply pattern to spectral component */ |
| 1575 |
ccy2rgb(&bsdfVal.spec, bsdfVal.cieY, bsdfRGB); |
| 1576 |
multcolor(bsdfRGB, rayIn -> pcol); |
| 1577 |
addcolor(bsdfRGB, nd.tdiff); |
| 1578 |
flipsurface(rayIn); /* Necessary? */ |
| 1579 |
nd.thick = -nd.thick; |
| 1580 |
photonRay(rayIn, &rayOut, PMAP_DIFFTRANS, bsdfRGB); |
| 1581 |
transmitted = 1; |
| 1582 |
} |
| 1583 |
|
| 1584 |
else if ((xi -= prSpecSD) <= 0) { |
| 1585 |
/* Non-diffuse ("specular") SDF reflection */ |
| 1586 |
if ((err = SDsampBSDF(&bsdfVal, nd.vray, pmapRandom(scatterState), |
| 1587 |
SDsampSp | SDsampR, nd.sd))) |
| 1588 |
objerror(mat, USER, transSDError(err)); |
| 1589 |
|
| 1590 |
ccy2rgb(&bsdfVal.spec, bsdfVal.cieY, bsdfRGB); |
| 1591 |
photonRay(rayIn, &rayOut, PMAP_SPECREFL, bsdfRGB); |
| 1592 |
} |
| 1593 |
|
| 1594 |
else { |
| 1595 |
/* Non-diffuse ("specular") SDF transmission */ |
| 1596 |
if ((err = SDsampBSDF(&bsdfVal, nd.vray, pmapRandom(scatterState), |
| 1597 |
SDsampSp | SDsampT, nd.sd))) |
| 1598 |
objerror(mat, USER, transSDError(err)); |
| 1599 |
|
| 1600 |
/* Apply pattern to spectral component */ |
| 1601 |
ccy2rgb(&bsdfVal.spec, bsdfVal.cieY, bsdfRGB); |
| 1602 |
multcolor(bsdfRGB, rayIn -> pcol); |
| 1603 |
flipsurface(rayIn); /* Necessary? */ |
| 1604 |
nd.thick = -nd.thick; |
| 1605 |
photonRay(rayIn, &rayOut, PMAP_SPECTRANS, bsdfRGB); |
| 1606 |
transmitted = 1; |
| 1607 |
} |
| 1608 |
|
| 1609 |
/* Xform outgoing dir to world coords */ |
| 1610 |
if ((err = SDmapDir(rayOut.rdir, nd.fromloc, nd.vray))) { |
| 1611 |
objerror(mat, USER, transSDError(err)); |
| 1612 |
return 0; |
| 1613 |
} |
| 1614 |
} |
| 1615 |
|
| 1616 |
/* Clean up */ |
| 1617 |
SDfreeCache(nd.sd); |
| 1618 |
|
| 1619 |
/* Need to offset ray origin to get past detail geometry? */ |
| 1620 |
if (transmitted && nd.thick != 0) |
| 1621 |
VSUM(rayOut.rorg, rayOut.rorg, rayIn -> ron, -nd.thick); |
| 1622 |
|
| 1623 |
tracePhoton(&rayOut); |
| 1624 |
return 0; |
| 1625 |
} |
| 1626 |
|
| 1627 |
|
| 1628 |
|
| 1629 |
static int lightPhotonScatter (OBJREC* mat, RAY* ray) |
| 1630 |
/* Light sources doan' reflect */ |
| 1631 |
{ |
| 1632 |
return 0; |
| 1633 |
} |
| 1634 |
|
| 1635 |
|
| 1636 |
|
| 1637 |
void initPhotonScatterFuncs () |
| 1638 |
/* Init photonScatter[] dispatch table */ |
| 1639 |
{ |
| 1640 |
int i; |
| 1641 |
|
| 1642 |
for (i = 0; i < NUMOTYPE; i++) |
| 1643 |
photonScatter [i] = o_default; |
| 1644 |
|
| 1645 |
photonScatter [MAT_LIGHT] = photonScatter [MAT_ILLUM] = |
| 1646 |
photonScatter [MAT_GLOW] = photonScatter [MAT_SPOT] = |
| 1647 |
lightPhotonScatter; |
| 1648 |
|
| 1649 |
photonScatter [MAT_PLASTIC] = photonScatter [MAT_METAL] = |
| 1650 |
photonScatter [MAT_TRANS] = normalPhotonScatter; |
| 1651 |
|
| 1652 |
photonScatter [MAT_PLASTIC2] = photonScatter [MAT_METAL2] = |
| 1653 |
photonScatter [MAT_TRANS2] = anisoPhotonScatter; |
| 1654 |
|
| 1655 |
photonScatter [MAT_DIELECTRIC] = photonScatter [MAT_INTERFACE] = |
| 1656 |
dielectricPhotonScatter; |
| 1657 |
|
| 1658 |
photonScatter [MAT_MIST] = mistPhotonScatter; |
| 1659 |
photonScatter [MAT_GLASS] = glassPhotonScatter; |
| 1660 |
photonScatter [MAT_CLIP] = clipPhotonScatter; |
| 1661 |
photonScatter [MAT_MIRROR] = mirrorPhotonScatter; |
| 1662 |
photonScatter [MIX_FUNC] = mx_funcPhotonScatter; |
| 1663 |
photonScatter [MIX_DATA] = mx_dataPhotonScatter; |
| 1664 |
photonScatter [MIX_PICT]= mx_pdataPhotonScatter; |
| 1665 |
|
| 1666 |
photonScatter [PAT_BDATA] = photonScatter [PAT_CDATA] = |
| 1667 |
photonScatter [PAT_BFUNC] = photonScatter [PAT_CFUNC] = |
| 1668 |
photonScatter [PAT_CPICT] = photonScatter [TEX_FUNC] = |
| 1669 |
photonScatter [TEX_DATA] = pattexPhotonScatter; |
| 1670 |
|
| 1671 |
photonScatter [MOD_ALIAS] = aliasPhotonScatter; |
| 1672 |
photonScatter [MAT_BSDF] = bsdfPhotonScatter; |
| 1673 |
} |
