| 1 |
/* |
| 2 |
================================================================== |
| 3 |
Photon map main module |
| 4 |
|
| 5 |
Roland Schregle (roland.schregle@{hslu.ch, gmail.com}) |
| 6 |
(c) Fraunhofer Institute for Solar Energy Systems, |
| 7 |
Lucerne University of Applied Sciences & Arts |
| 8 |
================================================================== |
| 9 |
|
| 10 |
$Id: pmap.c,v 2.1 2015/02/24 19:39:26 greg Exp $ |
| 11 |
*/ |
| 12 |
|
| 13 |
|
| 14 |
|
| 15 |
#include "pmap.h" |
| 16 |
#include "pmapmat.h" |
| 17 |
#include "pmapsrc.h" |
| 18 |
#include "pmaprand.h" |
| 19 |
#include "pmapio.h" |
| 20 |
#include "pmapbias.h" |
| 21 |
#include "pmapdiag.h" |
| 22 |
#include "otypes.h" |
| 23 |
#include <time.h> |
| 24 |
#include <sys/stat.h> |
| 25 |
|
| 26 |
|
| 27 |
|
| 28 |
extern char *octname; |
| 29 |
|
| 30 |
static char PmapRevision [] = "$Revision: 2.1 $"; |
| 31 |
|
| 32 |
|
| 33 |
|
| 34 |
/* Photon map lookup functions per type */ |
| 35 |
void (*pmapLookup [NUM_PMAP_TYPES])(PhotonMap*, RAY*, COLOR) = { |
| 36 |
photonDensity, photonPreCompDensity, photonDensity, volumePhotonDensity, |
| 37 |
photonDensity, NULL |
| 38 |
}; |
| 39 |
|
| 40 |
|
| 41 |
|
| 42 |
void colorNorm (COLOR c) |
| 43 |
/* Normalise colour channels to average of 1 */ |
| 44 |
{ |
| 45 |
const float avg = colorAvg(c); |
| 46 |
|
| 47 |
if (!avg) |
| 48 |
return; |
| 49 |
|
| 50 |
c [0] /= avg; |
| 51 |
c [1] /= avg; |
| 52 |
c [2] /= avg; |
| 53 |
} |
| 54 |
|
| 55 |
|
| 56 |
|
| 57 |
void loadPmaps (PhotonMap **pmaps, const PhotonMapParams *parm) |
| 58 |
{ |
| 59 |
unsigned t; |
| 60 |
struct stat octstat, pmstat; |
| 61 |
PhotonMap *pm; |
| 62 |
PhotonMapType type; |
| 63 |
|
| 64 |
for (t = 0; t < NUM_PMAP_TYPES; t++) |
| 65 |
if (setPmapParam(&pm, parm + t)) { |
| 66 |
/* Check if photon map newer than octree */ |
| 67 |
if (!stat(pm -> fileName, &pmstat) && !stat(octname, &octstat) && |
| 68 |
octstat.st_mtime > pmstat.st_mtime) { |
| 69 |
sprintf(errmsg, "photon map in file %s may be stale", |
| 70 |
pm -> fileName); |
| 71 |
error(USER, errmsg); |
| 72 |
} |
| 73 |
|
| 74 |
/* Load photon map from file and get its type */ |
| 75 |
if ((type = loadPhotonMap(pm, pm -> fileName)) == PMAP_TYPE_NONE) |
| 76 |
error(USER, "failed loading photon map"); |
| 77 |
|
| 78 |
/* Assign to appropriate photon map type (deleting previously |
| 79 |
* loaded photon map of same type if necessary) */ |
| 80 |
if (pmaps [type]) { |
| 81 |
deletePhotons(pmaps [type]); |
| 82 |
free(pmaps [type]); |
| 83 |
} |
| 84 |
pmaps [type] = pm; |
| 85 |
|
| 86 |
/* Check for invalid density estimate bandwidth */ |
| 87 |
if (pm -> maxGather > pm -> heapSize) { |
| 88 |
error(WARNING, "adjusting density estimate bandwidth"); |
| 89 |
pm -> minGather = pm -> maxGather = pm -> heapSize; |
| 90 |
} |
| 91 |
} |
| 92 |
} |
| 93 |
|
| 94 |
|
| 95 |
|
| 96 |
void savePmaps (const PhotonMap **pmaps, int argc, char **argv) |
| 97 |
{ |
| 98 |
unsigned t; |
| 99 |
|
| 100 |
for (t = 0; t < NUM_PMAP_TYPES; t++) { |
| 101 |
if (pmaps [t]) |
| 102 |
savePhotonMap(pmaps [t], pmaps [t] -> fileName, t, argc, argv); |
| 103 |
} |
| 104 |
} |
| 105 |
|
| 106 |
|
| 107 |
|
| 108 |
void cleanUpPmaps (PhotonMap **pmaps) |
| 109 |
{ |
| 110 |
unsigned t; |
| 111 |
|
| 112 |
for (t = 0; t < NUM_PMAP_TYPES; t++) { |
| 113 |
if (pmaps [t]) { |
| 114 |
deletePhotons(pmaps [t]); |
| 115 |
free(pmaps [t]); |
| 116 |
} |
| 117 |
} |
| 118 |
} |
| 119 |
|
| 120 |
|
| 121 |
|
| 122 |
static int photonParticipate (RAY *ray) |
| 123 |
/* Trace photon through participating medium. Returns 1 if passed through, |
| 124 |
or 0 if absorbed and $*%&ed. Analogon to rayparticipate(). */ |
| 125 |
{ |
| 126 |
int i; |
| 127 |
RREAL cosTheta, cosPhi, du, dv; |
| 128 |
const float cext = colorAvg(ray -> cext), |
| 129 |
albedo = colorAvg(ray -> albedo); |
| 130 |
FVECT u, v; |
| 131 |
COLOR cvext; |
| 132 |
|
| 133 |
/* Mean free distance until interaction with medium */ |
| 134 |
ray -> rmax = -log(pmapRandom(mediumState)) / cext; |
| 135 |
|
| 136 |
while (!localhit(ray, &thescene)) { |
| 137 |
setcolor(cvext, exp(-ray -> rmax * ray -> cext [0]), |
| 138 |
exp(-ray -> rmax * ray -> cext [1]), |
| 139 |
exp(-ray -> rmax * ray -> cext [2])); |
| 140 |
|
| 141 |
/* Modify ray color and normalise */ |
| 142 |
multcolor(ray -> rcol, cvext); |
| 143 |
colorNorm(ray -> rcol); |
| 144 |
VCOPY(ray -> rorg, ray -> rop); |
| 145 |
|
| 146 |
if (albedo > FTINY) |
| 147 |
/* Add to volume photon map */ |
| 148 |
if (ray -> rlvl > 0) addPhoton(volumePmap, ray); |
| 149 |
|
| 150 |
/* Absorbed? */ |
| 151 |
if (pmapRandom(rouletteState) > albedo) return 0; |
| 152 |
|
| 153 |
/* Colour bleeding without attenuation (?) */ |
| 154 |
multcolor(ray -> rcol, ray -> albedo); |
| 155 |
scalecolor(ray -> rcol, 1 / albedo); |
| 156 |
|
| 157 |
/* Scatter photon */ |
| 158 |
cosTheta = ray -> gecc <= FTINY ? 2 * pmapRandom(scatterState) - 1 |
| 159 |
: 1 / (2 * ray -> gecc) * |
| 160 |
(1 + ray -> gecc * ray -> gecc - |
| 161 |
(1 - ray -> gecc * ray -> gecc) / |
| 162 |
(1 - ray -> gecc + 2 * ray -> gecc * |
| 163 |
pmapRandom(scatterState))); |
| 164 |
|
| 165 |
cosPhi = cos(2 * PI * pmapRandom(scatterState)); |
| 166 |
du = dv = sqrt(1 - cosTheta * cosTheta); /* sin(theta) */ |
| 167 |
du *= cosPhi; |
| 168 |
dv *= sqrt(1 - cosPhi * cosPhi); /* sin(phi) */ |
| 169 |
|
| 170 |
/* Get axes u & v perpendicular to photon direction */ |
| 171 |
i = 0; |
| 172 |
do { |
| 173 |
v [0] = v [1] = v [2] = 0; |
| 174 |
v [i++] = 1; |
| 175 |
fcross(u, v, ray -> rdir); |
| 176 |
} while (normalize(u) < FTINY); |
| 177 |
fcross(v, ray -> rdir, u); |
| 178 |
|
| 179 |
for (i = 0; i < 3; i++) |
| 180 |
ray -> rdir [i] = du * u [i] + dv * v [i] + |
| 181 |
cosTheta * ray -> rdir [i]; |
| 182 |
ray -> rlvl++; |
| 183 |
ray -> rmax = -log(pmapRandom(mediumState)) / cext; |
| 184 |
} |
| 185 |
|
| 186 |
setcolor(cvext, exp(-ray -> rot * ray -> cext [0]), |
| 187 |
exp(-ray -> rot * ray -> cext [1]), |
| 188 |
exp(-ray -> rot * ray -> cext [2])); |
| 189 |
|
| 190 |
/* Modify ray color and normalise */ |
| 191 |
multcolor(ray -> rcol, cvext); |
| 192 |
colorNorm(ray -> rcol); |
| 193 |
|
| 194 |
/* Passed through medium */ |
| 195 |
return 1; |
| 196 |
} |
| 197 |
|
| 198 |
|
| 199 |
|
| 200 |
void tracePhoton (RAY *ray) |
| 201 |
/* Follow photon as it bounces around... */ |
| 202 |
{ |
| 203 |
long mod; |
| 204 |
OBJREC* mat; |
| 205 |
|
| 206 |
if (ray -> rlvl > photonMaxBounce) { |
| 207 |
error(WARNING, "runaway photon!"); |
| 208 |
return; |
| 209 |
} |
| 210 |
|
| 211 |
if (colorAvg(ray -> cext) > FTINY && !photonParticipate(ray)) |
| 212 |
return; |
| 213 |
|
| 214 |
if (localhit(ray, &thescene)) { |
| 215 |
mod = ray -> ro -> omod; |
| 216 |
|
| 217 |
if ((ray -> clipset && inset(ray -> clipset, mod)) || mod == OVOID) { |
| 218 |
/* Transfer ray if modifier is VOID or clipped within antimatta */ |
| 219 |
RAY tray; |
| 220 |
photonRay(ray, &tray, PMAP_XFER, NULL); |
| 221 |
tracePhoton(&tray); |
| 222 |
} |
| 223 |
else { |
| 224 |
/* Scatter for modifier material */ |
| 225 |
mat = objptr(mod); |
| 226 |
photonScatter [mat -> otype] (mat, ray); |
| 227 |
} |
| 228 |
} |
| 229 |
} |
| 230 |
|
| 231 |
|
| 232 |
|
| 233 |
static void preComputeGlobal (PhotonMap *pmap) |
| 234 |
/* Precompute irradiance from global photons for final gathering using |
| 235 |
the first finalGather * pmap -> heapSize photons in the heap. Returns |
| 236 |
new heap with precomputed photons. */ |
| 237 |
{ |
| 238 |
unsigned long i, nuHeapSize; |
| 239 |
unsigned j; |
| 240 |
Photon *nuHeap, *p; |
| 241 |
COLOR irrad; |
| 242 |
RAY ray; |
| 243 |
float nuMinPos [3], nuMaxPos [3]; |
| 244 |
|
| 245 |
repComplete = nuHeapSize = finalGather * pmap -> heapSize; |
| 246 |
|
| 247 |
if (photonRepTime) { |
| 248 |
sprintf(errmsg, |
| 249 |
"Precomputing irradiance for %ld global photons...\n", |
| 250 |
nuHeapSize); |
| 251 |
eputs(errmsg); |
| 252 |
fflush(stderr); |
| 253 |
} |
| 254 |
|
| 255 |
p = nuHeap = (Photon*)malloc(nuHeapSize * sizeof(Photon)); |
| 256 |
if (!nuHeap) |
| 257 |
error(USER, "can't allocate photon heap"); |
| 258 |
|
| 259 |
for (j = 0; j <= 2; j++) { |
| 260 |
nuMinPos [j] = FHUGE; |
| 261 |
nuMaxPos [j] = -FHUGE; |
| 262 |
} |
| 263 |
|
| 264 |
/* Record start time, baby */ |
| 265 |
repStartTime = time(NULL); |
| 266 |
signal(SIGCONT, pmapPreCompReport); |
| 267 |
repProgress = 0; |
| 268 |
memcpy(nuHeap, pmap -> heap, nuHeapSize * sizeof(Photon)); |
| 269 |
|
| 270 |
for (i = 0, p = nuHeap; i < nuHeapSize; i++, p++) { |
| 271 |
ray.ro = NULL; |
| 272 |
VCOPY(ray.rop, p -> pos); |
| 273 |
|
| 274 |
/* Update min and max positions & set ray normal */ |
| 275 |
for (j = 0; j < 3; j++) { |
| 276 |
if (p -> pos [j] < nuMinPos [j]) nuMinPos [j] = p -> pos [j]; |
| 277 |
if (p -> pos [j] > nuMaxPos [j]) nuMaxPos [j] = p -> pos [j]; |
| 278 |
ray.ron [j] = p -> norm [j] / 127.0; |
| 279 |
} |
| 280 |
|
| 281 |
photonDensity(pmap, &ray, irrad); |
| 282 |
setPhotonFlux(p, irrad); |
| 283 |
repProgress++; |
| 284 |
|
| 285 |
if (photonRepTime > 0 && time(NULL) >= repLastTime + photonRepTime) |
| 286 |
pmapPreCompReport(); |
| 287 |
#ifndef BSD |
| 288 |
else signal(SIGCONT, pmapPreCompReport); |
| 289 |
#endif |
| 290 |
} |
| 291 |
|
| 292 |
signal(SIGCONT, SIG_DFL); |
| 293 |
|
| 294 |
/* Replace & rebuild heap */ |
| 295 |
free(pmap -> heap); |
| 296 |
pmap -> heap = nuHeap; |
| 297 |
pmap -> heapSize = pmap -> heapEnd = nuHeapSize; |
| 298 |
VCOPY(pmap -> minPos, nuMinPos); |
| 299 |
VCOPY(pmap -> maxPos, nuMaxPos); |
| 300 |
|
| 301 |
if (photonRepTime) { |
| 302 |
eputs("Rebuilding global photon heap...\n"); |
| 303 |
fflush(stderr); |
| 304 |
} |
| 305 |
|
| 306 |
balancePhotons(pmap, NULL); |
| 307 |
} |
| 308 |
|
| 309 |
|
| 310 |
|
| 311 |
void distribPhotons (PhotonMap **pmaps) |
| 312 |
{ |
| 313 |
EmissionMap emap; |
| 314 |
char errmsg2 [128]; |
| 315 |
unsigned t, srcIdx, passCnt = 0, prePassCnt = 0; |
| 316 |
double totalFlux = 0; |
| 317 |
PhotonMap *pm; |
| 318 |
|
| 319 |
for (t = 0; t < NUM_PMAP_TYPES && !photonMaps [t]; t++); |
| 320 |
if (t >= NUM_PMAP_TYPES) |
| 321 |
error(USER, "no photon maps defined"); |
| 322 |
|
| 323 |
if (!nsources) |
| 324 |
error(USER, "no light sources"); |
| 325 |
|
| 326 |
/* =================================================================== |
| 327 |
* INITIALISATION - Set up emission and scattering funcs |
| 328 |
* =================================================================== */ |
| 329 |
emap.samples = NULL; |
| 330 |
emap.maxPartitions = MAXSPART; |
| 331 |
emap.partitions = (unsigned char*)malloc(emap.maxPartitions >> 1); |
| 332 |
if (!emap.partitions) |
| 333 |
error(INTERNAL, "can't allocate source partitions"); |
| 334 |
|
| 335 |
/* Initialise all defined photon maps */ |
| 336 |
for (t = 0; t < NUM_PMAP_TYPES; t++) |
| 337 |
initPhotonMap(photonMaps [t], t); |
| 338 |
|
| 339 |
initPhotonEmissionFuncs(); |
| 340 |
initPhotonScatterFuncs(); |
| 341 |
|
| 342 |
/* Get photon ports if specified */ |
| 343 |
if (ambincl == 1) |
| 344 |
getPhotonPorts(); |
| 345 |
|
| 346 |
/* Get photon sensor modifiers */ |
| 347 |
getPhotonSensors(photonSensorList); |
| 348 |
|
| 349 |
/* Seed RNGs for photon distribution */ |
| 350 |
pmapSeed(randSeed, partState); |
| 351 |
pmapSeed(randSeed, emitState); |
| 352 |
pmapSeed(randSeed, cntState); |
| 353 |
pmapSeed(randSeed, mediumState); |
| 354 |
pmapSeed(randSeed, scatterState); |
| 355 |
pmapSeed(randSeed, rouletteState); |
| 356 |
|
| 357 |
if (photonRepTime) |
| 358 |
eputs("\n"); |
| 359 |
|
| 360 |
/* =================================================================== |
| 361 |
* FLUX INTEGRATION - Get total photon flux from light sources |
| 362 |
* =================================================================== */ |
| 363 |
for (srcIdx = 0; srcIdx < nsources; srcIdx++) { |
| 364 |
unsigned portCnt = 0; |
| 365 |
emap.src = source + srcIdx; |
| 366 |
|
| 367 |
do { |
| 368 |
emap.port = emap.src -> sflags & SDISTANT ? photonPorts + portCnt |
| 369 |
: NULL; |
| 370 |
photonPartition [emap.src -> so -> otype] (&emap); |
| 371 |
|
| 372 |
if (photonRepTime) { |
| 373 |
sprintf(errmsg, "Integrating flux from source %s ", |
| 374 |
source [srcIdx].so -> oname); |
| 375 |
|
| 376 |
if (emap.port) { |
| 377 |
sprintf(errmsg2, "via port %s ", |
| 378 |
photonPorts [portCnt].so -> oname); |
| 379 |
strcat(errmsg, errmsg2); |
| 380 |
} |
| 381 |
|
| 382 |
sprintf(errmsg2, "(%lu partitions)...\n", emap.numPartitions); |
| 383 |
strcat(errmsg, errmsg2); |
| 384 |
eputs(errmsg); |
| 385 |
fflush(stderr); |
| 386 |
} |
| 387 |
|
| 388 |
for (emap.partitionCnt = 0; emap.partitionCnt < emap.numPartitions; |
| 389 |
emap.partitionCnt++) { |
| 390 |
initPhotonEmission(&emap, pdfSamples); |
| 391 |
totalFlux += colorAvg(emap.partFlux); |
| 392 |
} |
| 393 |
|
| 394 |
portCnt++; |
| 395 |
} while (portCnt < numPhotonPorts); |
| 396 |
} |
| 397 |
|
| 398 |
if (totalFlux < FTINY) |
| 399 |
error(USER, "zero flux from light sources"); |
| 400 |
|
| 401 |
/* Record start time and enable progress report signal handler */ |
| 402 |
repStartTime = time(NULL); |
| 403 |
signal(SIGCONT, pmapDistribReport); |
| 404 |
repProgress = prePassCnt = 0; |
| 405 |
|
| 406 |
if (photonRepTime) |
| 407 |
eputs("\n"); |
| 408 |
|
| 409 |
/* =================================================================== |
| 410 |
* 2-PASS PHOTON DISTRIBUTION |
| 411 |
* Pass 1 (pre): emit fraction of target photon count |
| 412 |
* Pass 2 (main): based on outcome of pass 1, estimate remaining number |
| 413 |
* of photons to emit to approximate target count |
| 414 |
* =================================================================== */ |
| 415 |
do { |
| 416 |
double numEmit; |
| 417 |
|
| 418 |
if (!passCnt) { |
| 419 |
/* INIT PASS 1 */ |
| 420 |
/* Skip if no photons contributed after sufficient iterations; make |
| 421 |
* it clear to user which photon maps are missing so (s)he can |
| 422 |
* check the scene geometry and materials */ |
| 423 |
if (++prePassCnt > maxPreDistrib) { |
| 424 |
sprintf(errmsg, "too many prepasses"); |
| 425 |
|
| 426 |
for (t = 0; t < NUM_PMAP_TYPES; t++) |
| 427 |
if (photonMaps [t] && !photonMaps [t] -> heapEnd) { |
| 428 |
sprintf(errmsg2, ", no %s photons stored", pmapName [t]); |
| 429 |
strcat(errmsg, errmsg2); |
| 430 |
} |
| 431 |
|
| 432 |
error(USER, errmsg); |
| 433 |
break; |
| 434 |
} |
| 435 |
|
| 436 |
/* Num to emit is fraction of minimum target count */ |
| 437 |
numEmit = FHUGE; |
| 438 |
|
| 439 |
for (t = 0; t < NUM_PMAP_TYPES; t++) |
| 440 |
if (photonMaps [t]) |
| 441 |
numEmit = min(photonMaps [t] -> distribTarget, numEmit); |
| 442 |
|
| 443 |
numEmit *= preDistrib; |
| 444 |
} |
| 445 |
|
| 446 |
else { |
| 447 |
/* INIT PASS 2 */ |
| 448 |
/* Based on the outcome of the predistribution we can now estimate |
| 449 |
* how many more photons we have to emit for each photon map to |
| 450 |
* meet its respective target count. This value is clamped to 0 in |
| 451 |
* case the target has already been exceeded in the pass 1. Note |
| 452 |
* repProgress is the number of photons emitted thus far, while |
| 453 |
* heapEnd is the number of photons stored in each photon map. */ |
| 454 |
double maxDistribRatio = 0; |
| 455 |
|
| 456 |
/* Set the distribution ratio for each map; this indicates how many |
| 457 |
* photons of each respective type are stored per emitted photon, |
| 458 |
* and is used as probability for storing a photon by addPhoton(). |
| 459 |
* Since this biases the photon density, addPhoton() promotes the |
| 460 |
* flux of stored photons to compensate. */ |
| 461 |
for (t = 0; t < NUM_PMAP_TYPES; t++) |
| 462 |
if ((pm = photonMaps [t])) { |
| 463 |
pm -> distribRatio = (double)pm -> distribTarget / |
| 464 |
pm -> heapEnd - 1; |
| 465 |
|
| 466 |
/* Check if photon map "overflowed", i.e. exceeded its target |
| 467 |
* count in the prepass; correcting the photon flux via the |
| 468 |
* distribution ratio is no longer possible, as no more |
| 469 |
* photons of this type will be stored, so notify the user |
| 470 |
* rather than deliver incorrect results. |
| 471 |
* In future we should handle this more intelligently by |
| 472 |
* using the photonFlux in each photon map to individually |
| 473 |
* correct the flux after distribution. */ |
| 474 |
if (pm -> distribRatio <= FTINY) { |
| 475 |
sprintf(errmsg, |
| 476 |
"%s photon map overflow in prepass, reduce -apD", |
| 477 |
pmapName [t]); |
| 478 |
error(INTERNAL, errmsg); |
| 479 |
} |
| 480 |
|
| 481 |
maxDistribRatio = max(pm -> distribRatio, maxDistribRatio); |
| 482 |
} |
| 483 |
|
| 484 |
/* Normalise distribution ratios and calculate number of photons to |
| 485 |
* emit in main pass */ |
| 486 |
for (t = 0; t < NUM_PMAP_TYPES; t++) |
| 487 |
if ((pm = photonMaps [t])) |
| 488 |
pm -> distribRatio /= maxDistribRatio; |
| 489 |
|
| 490 |
if ((numEmit = repProgress * maxDistribRatio) < FTINY) |
| 491 |
/* No photons left to distribute in main pass */ |
| 492 |
break; |
| 493 |
} |
| 494 |
|
| 495 |
/* Set completion count for progress report */ |
| 496 |
repComplete = numEmit + repProgress; |
| 497 |
|
| 498 |
/* PHOTON DISTRIBUTION LOOP */ |
| 499 |
for (srcIdx = 0; srcIdx < nsources; srcIdx++) { |
| 500 |
unsigned portCnt = 0; |
| 501 |
emap.src = source + srcIdx; |
| 502 |
|
| 503 |
do { |
| 504 |
emap.port = emap.src -> sflags & SDISTANT ? photonPorts + portCnt |
| 505 |
: NULL; |
| 506 |
photonPartition [emap.src -> so -> otype] (&emap); |
| 507 |
|
| 508 |
if (photonRepTime) { |
| 509 |
if (!passCnt) |
| 510 |
sprintf(errmsg, "PREPASS %d on source %s ", |
| 511 |
prePassCnt, source [srcIdx].so -> oname); |
| 512 |
else |
| 513 |
sprintf(errmsg, "MAIN PASS on source %s ", |
| 514 |
source [srcIdx].so -> oname); |
| 515 |
|
| 516 |
if (emap.port) { |
| 517 |
sprintf(errmsg2, "via port %s ", |
| 518 |
photonPorts [portCnt].so -> oname); |
| 519 |
strcat(errmsg, errmsg2); |
| 520 |
} |
| 521 |
|
| 522 |
sprintf(errmsg2, "(%lu partitions)...\n", emap.numPartitions); |
| 523 |
strcat(errmsg, errmsg2); |
| 524 |
eputs(errmsg); |
| 525 |
fflush(stderr); |
| 526 |
} |
| 527 |
|
| 528 |
for (emap.partitionCnt = 0; emap.partitionCnt < emap.numPartitions; |
| 529 |
emap.partitionCnt++) { |
| 530 |
double partNumEmit; |
| 531 |
unsigned long partEmitCnt; |
| 532 |
|
| 533 |
/* Get photon origin within current source partishunn and |
| 534 |
* build emission map */ |
| 535 |
photonOrigin [emap.src -> so -> otype] (&emap); |
| 536 |
initPhotonEmission(&emap, pdfSamples); |
| 537 |
|
| 538 |
/* Number of photons to emit from ziss partishunn -- |
| 539 |
* proportional to flux; photon ray weight and scalar flux |
| 540 |
* are uniform (the latter only varying in RGB). */ |
| 541 |
partNumEmit = numEmit * colorAvg(emap.partFlux) / totalFlux; |
| 542 |
partEmitCnt = (unsigned long)partNumEmit; |
| 543 |
|
| 544 |
/* Probabilistically account for fractional photons */ |
| 545 |
if (pmapRandom(cntState) < partNumEmit - partEmitCnt) |
| 546 |
partEmitCnt++; |
| 547 |
|
| 548 |
/* Integer counter avoids FP rounding errors */ |
| 549 |
while (partEmitCnt--) { |
| 550 |
RAY photonRay; |
| 551 |
|
| 552 |
/* Emit photon based on PDF and trace through scene until |
| 553 |
* absorbed/leaked */ |
| 554 |
emitPhoton(&emap, &photonRay); |
| 555 |
tracePhoton(&photonRay); |
| 556 |
|
| 557 |
/* Record progress */ |
| 558 |
repProgress++; |
| 559 |
|
| 560 |
if (photonRepTime > 0 && |
| 561 |
time(NULL) >= repLastTime + photonRepTime) |
| 562 |
pmapDistribReport(); |
| 563 |
#ifndef BSD |
| 564 |
else signal(SIGCONT, pmapDistribReport); |
| 565 |
#endif |
| 566 |
} |
| 567 |
} |
| 568 |
|
| 569 |
portCnt++; |
| 570 |
} while (portCnt < numPhotonPorts); |
| 571 |
} |
| 572 |
|
| 573 |
for (t = 0; t < NUM_PMAP_TYPES; t++) |
| 574 |
if (photonMaps [t] && !photonMaps [t] -> heapEnd) { |
| 575 |
/* Double preDistrib in case a photon map is empty and redo |
| 576 |
* pass 1 --> possibility of infinite loop for pathological |
| 577 |
* scenes (e.g. absorbing materials) */ |
| 578 |
preDistrib *= 2; |
| 579 |
break; |
| 580 |
} |
| 581 |
|
| 582 |
if (t >= NUM_PMAP_TYPES) { |
| 583 |
/* No empty photon maps found; now do pass 2 */ |
| 584 |
passCnt++; |
| 585 |
if (photonRepTime) |
| 586 |
eputs("\n"); |
| 587 |
} |
| 588 |
} while (passCnt < 2); |
| 589 |
|
| 590 |
/* =================================================================== |
| 591 |
* POST-DISTRIBUTION - Set photon flux and build kd-tree, etc. |
| 592 |
* =================================================================== */ |
| 593 |
signal(SIGCONT, SIG_DFL); |
| 594 |
free(emap.samples); |
| 595 |
|
| 596 |
/* Set photon flux (repProgress is total num emitted) */ |
| 597 |
totalFlux /= repProgress; |
| 598 |
|
| 599 |
for (t = 0; t < NUM_PMAP_TYPES; t++) |
| 600 |
if (photonMaps [t]) { |
| 601 |
if (photonRepTime) { |
| 602 |
sprintf(errmsg, "\nBuilding %s photon map...\n", pmapName [t]); |
| 603 |
eputs(errmsg); |
| 604 |
fflush(stderr); |
| 605 |
} |
| 606 |
|
| 607 |
balancePhotons(photonMaps [t], &totalFlux); |
| 608 |
} |
| 609 |
|
| 610 |
/* Precompute photon irradiance if necessary */ |
| 611 |
if (preCompPmap) |
| 612 |
preComputeGlobal(preCompPmap); |
| 613 |
} |
| 614 |
|
| 615 |
|
| 616 |
|
| 617 |
void photonDensity (PhotonMap *pmap, RAY *ray, COLOR irrad) |
| 618 |
/* Photon density estimate. Returns irradiance at ray -> rop. */ |
| 619 |
{ |
| 620 |
unsigned i; |
| 621 |
PhotonSQNode *sq; |
| 622 |
float r; |
| 623 |
COLOR flux; |
| 624 |
|
| 625 |
setcolor(irrad, 0, 0, 0); |
| 626 |
|
| 627 |
if (!pmap -> maxGather) |
| 628 |
return; |
| 629 |
|
| 630 |
/* Ignore sources */ |
| 631 |
if (ray -> ro) |
| 632 |
if (islight(objptr(ray -> ro -> omod) -> otype)) |
| 633 |
return; |
| 634 |
|
| 635 |
pmap -> squeueEnd = 0; |
| 636 |
findPhotons(pmap, ray); |
| 637 |
|
| 638 |
/* Need at least 2 photons */ |
| 639 |
if (pmap -> squeueEnd < 2) { |
| 640 |
#ifdef PMAP_NONEFOUND |
| 641 |
sprintf(errmsg, "no photons found on %s at (%.3f, %.3f, %.3f)", |
| 642 |
ray -> ro ? ray -> ro -> oname : "<null>", |
| 643 |
ray -> rop [0], ray -> rop [1], ray -> rop [2]); |
| 644 |
error(WARNING, errmsg); |
| 645 |
#endif |
| 646 |
|
| 647 |
return; |
| 648 |
} |
| 649 |
|
| 650 |
if (pmap -> minGather == pmap -> maxGather) { |
| 651 |
/* No bias compensation. Just do a plain vanilla estimate */ |
| 652 |
sq = pmap -> squeue + 1; |
| 653 |
|
| 654 |
/* Average radius between furthest two photons to improve accuracy */ |
| 655 |
r = max(sq -> dist, (sq + 1) -> dist); |
| 656 |
r = 0.25 * (pmap -> maxDist + r + 2 * sqrt(pmap -> maxDist * r)); |
| 657 |
|
| 658 |
/* Skip the extra photon */ |
| 659 |
for (i = 1 ; i < pmap -> squeueEnd; i++, sq++) { |
| 660 |
getPhotonFlux(sq -> photon, flux); |
| 661 |
#ifdef PMAP_EPANECHNIKOV |
| 662 |
/* Apply Epanechnikov kernel to photon flux (dists are squared) */ |
| 663 |
scalecolor(flux, 2 * (1 - sq -> dist / r)); |
| 664 |
#endif |
| 665 |
addcolor(irrad, flux); |
| 666 |
} |
| 667 |
|
| 668 |
/* Divide by search area PI * r^2, 1 / PI required as ambient |
| 669 |
normalisation factor */ |
| 670 |
scalecolor(irrad, 1 / (PI * PI * r)); |
| 671 |
|
| 672 |
return; |
| 673 |
} |
| 674 |
else |
| 675 |
/* Apply bias compensation to density estimate */ |
| 676 |
biasComp(pmap, irrad); |
| 677 |
} |
| 678 |
|
| 679 |
|
| 680 |
|
| 681 |
void photonPreCompDensity (PhotonMap *pmap, RAY *r, COLOR irrad) |
| 682 |
/* Returns precomputed photon density estimate at ray -> rop. */ |
| 683 |
{ |
| 684 |
Photon *p; |
| 685 |
|
| 686 |
setcolor(irrad, 0, 0, 0); |
| 687 |
|
| 688 |
/* Ignore sources */ |
| 689 |
if (r -> ro && islight(objptr(r -> ro -> omod) -> otype)) |
| 690 |
return; |
| 691 |
|
| 692 |
if ((p = find1Photon(preCompPmap, r))) |
| 693 |
getPhotonFlux(p, irrad); |
| 694 |
} |
| 695 |
|
| 696 |
|
| 697 |
|
| 698 |
void volumePhotonDensity (PhotonMap *pmap, RAY *ray, COLOR irrad) |
| 699 |
/* Photon volume density estimate. Returns irradiance at ray -> rop. */ |
| 700 |
{ |
| 701 |
unsigned i; |
| 702 |
PhotonSQNode *sq; |
| 703 |
float gecc2, r, ph; |
| 704 |
COLOR flux; |
| 705 |
|
| 706 |
setcolor(irrad, 0, 0, 0); |
| 707 |
|
| 708 |
if (!pmap -> maxGather) |
| 709 |
return; |
| 710 |
|
| 711 |
pmap -> squeueEnd = 0; |
| 712 |
findPhotons(pmap, ray); |
| 713 |
|
| 714 |
/* Need at least 2 photons */ |
| 715 |
if (pmap -> squeueEnd < 2) |
| 716 |
return; |
| 717 |
|
| 718 |
if (pmap -> minGather == pmap -> maxGather) { |
| 719 |
/* No bias compensation. Just do a plain vanilla estimate */ |
| 720 |
gecc2 = ray -> gecc * ray -> gecc; |
| 721 |
sq = pmap -> squeue + 1; |
| 722 |
|
| 723 |
/* Average radius between furthest two photons to improve accuracy */ |
| 724 |
r = max(sq -> dist, (sq + 1) -> dist); |
| 725 |
r = 0.25 * (pmap -> maxDist + r + 2 * sqrt(pmap -> maxDist * r)); |
| 726 |
|
| 727 |
/* Skip the extra photon */ |
| 728 |
for (i = 1 ; i < pmap -> squeueEnd; i++, sq++) { |
| 729 |
/* Compute phase function for inscattering from photon */ |
| 730 |
if (gecc2 <= FTINY) |
| 731 |
ph = 1; |
| 732 |
else { |
| 733 |
ph = DOT(ray -> rdir, sq -> photon -> norm) / 127; |
| 734 |
ph = 1 + gecc2 - 2 * ray -> gecc * ph; |
| 735 |
ph = (1 - gecc2) / (ph * sqrt(ph)); |
| 736 |
} |
| 737 |
|
| 738 |
getPhotonFlux(sq -> photon, flux); |
| 739 |
scalecolor(flux, ph); |
| 740 |
addcolor(irrad, flux); |
| 741 |
} |
| 742 |
|
| 743 |
/* Divide by search volume 4 / 3 * PI * r^3 and phase function |
| 744 |
normalization factor 1 / (4 * PI) */ |
| 745 |
scalecolor(irrad, 3 / (16 * PI * PI * r * sqrt(r))); |
| 746 |
|
| 747 |
return; |
| 748 |
} |
| 749 |
|
| 750 |
else |
| 751 |
/* Apply bias compensation to density estimate */ |
| 752 |
volumeBiasComp(pmap, ray, irrad); |
| 753 |
} |
