| 1 |
/* |
| 2 |
================================================================== |
| 3 |
Photon map support for light source contributions |
| 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: pmapcontrib.c,v 2.1 2015/02/24 19:39:26 greg Exp $ |
| 11 |
*/ |
| 12 |
|
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|
| 14 |
#include "pmapcontrib.h" |
| 15 |
#include "pmap.h" |
| 16 |
#include "pmapmat.h" |
| 17 |
#include "pmapsrc.h" |
| 18 |
#include "pmaprand.h" |
| 19 |
#include "pmapio.h" |
| 20 |
#include "pmapdiag.h" |
| 21 |
#include "rcontrib.h" |
| 22 |
#include "otypes.h" |
| 23 |
|
| 24 |
|
| 25 |
|
| 26 |
extern int contrib; /* coeff/contrib flag */ |
| 27 |
|
| 28 |
|
| 29 |
|
| 30 |
static void setPmapContribParams (PhotonMap *pmap, LUTAB *srcContrib) |
| 31 |
/* Set parameters for light source contributions */ |
| 32 |
{ |
| 33 |
/* Set light source modifier list and appropriate callback to extract |
| 34 |
* their contributions from the photon map */ |
| 35 |
if (pmap) { |
| 36 |
pmap -> srcContrib = srcContrib; |
| 37 |
pmap -> lookup = photonContrib; |
| 38 |
/* Ensure we get all requested photon contribs during lookups */ |
| 39 |
pmap -> gatherTolerance = 1.0; |
| 40 |
} |
| 41 |
} |
| 42 |
|
| 43 |
|
| 44 |
|
| 45 |
static void checkPmapContribs (const PhotonMap *pmap, LUTAB *srcContrib) |
| 46 |
/* Check modifiers for light source contributions */ |
| 47 |
{ |
| 48 |
const PhotonPrimary *primary = pmap -> primary; |
| 49 |
OBJREC *srcMod; |
| 50 |
unsigned long i, found = 0; |
| 51 |
|
| 52 |
/* Make sure at least one of the modifiers is actually in the pmap, |
| 53 |
* otherwise findPhotons() winds up in an infinite loop! */ |
| 54 |
for (i = pmap -> primarySize; i; --i, ++primary) { |
| 55 |
if (primary -> srcIdx < 0 || primary -> srcIdx >= nsources) |
| 56 |
error(INTERNAL, "invalid light source index in photon map"); |
| 57 |
|
| 58 |
srcMod = objptr(source [primary -> srcIdx].so -> omod); |
| 59 |
if ((MODCONT*)lu_find(srcContrib, srcMod -> oname) -> data) |
| 60 |
++found; |
| 61 |
} |
| 62 |
|
| 63 |
if (!found) |
| 64 |
error(USER, "modifiers not in photon map"); |
| 65 |
} |
| 66 |
|
| 67 |
|
| 68 |
|
| 69 |
void initPmapContrib (LUTAB *srcContrib, unsigned numSrcContrib) |
| 70 |
{ |
| 71 |
unsigned t; |
| 72 |
|
| 73 |
for (t = 0; t < NUM_PMAP_TYPES; t++) |
| 74 |
if (photonMaps [t] && t != PMAP_TYPE_CONTRIB) { |
| 75 |
sprintf(errmsg, "%s photon map does not support contributions", |
| 76 |
pmapName [t]); |
| 77 |
error(USER, errmsg); |
| 78 |
} |
| 79 |
|
| 80 |
/* Get params */ |
| 81 |
setPmapContribParams(contribPmap, srcContrib); |
| 82 |
|
| 83 |
if (contribPhotonMapping) { |
| 84 |
if (contribPmap -> maxGather < numSrcContrib) { |
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/* Adjust density estimate bandwidth if lower than modifier |
| 86 |
* count, otherwise contributions are missing */ |
| 87 |
error(WARNING, "contrib density estimate bandwidth too low, " |
| 88 |
"adjusting to modifier count"); |
| 89 |
contribPmap -> maxGather = numSrcContrib; |
| 90 |
} |
| 91 |
|
| 92 |
/* Sanity check */ |
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checkPmapContribs(contribPmap, srcContrib); |
| 94 |
} |
| 95 |
} |
| 96 |
|
| 97 |
|
| 98 |
|
| 99 |
void photonContrib (PhotonMap *pmap, RAY *ray, COLOR irrad) |
| 100 |
/* Sum up light source contributions from photons in pmap->srcContrib */ |
| 101 |
{ |
| 102 |
unsigned i; |
| 103 |
PhotonSQNode *sq; |
| 104 |
float r, invArea; |
| 105 |
RREAL rayCoeff [3]; |
| 106 |
FVECT rdir, rop; |
| 107 |
|
| 108 |
setcolor(irrad, 0, 0, 0); |
| 109 |
|
| 110 |
if (!pmap -> maxGather) |
| 111 |
return; |
| 112 |
|
| 113 |
/* Ignore sources */ |
| 114 |
if (ray -> ro) |
| 115 |
if (islight(objptr(ray -> ro -> omod) -> otype)) |
| 116 |
return; |
| 117 |
|
| 118 |
/* Set context for binning function evaluation and get cumulative path |
| 119 |
* coefficient up to photon lookup point */ |
| 120 |
worldfunc(RCCONTEXT, ray); |
| 121 |
raycontrib(rayCoeff, ray, PRIMARY); |
| 122 |
|
| 123 |
/* Save incident ray's direction and hitpoint */ |
| 124 |
VCOPY(rdir, ray -> rdir); |
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VCOPY(rop, ray -> rop); |
| 126 |
|
| 127 |
/* Lookup photons */ |
| 128 |
pmap -> squeueEnd = 0; |
| 129 |
findPhotons(pmap, ray); |
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|
| 131 |
/* Need at least 2 photons */ |
| 132 |
if (pmap -> squeueEnd < 2) { |
| 133 |
#ifdef PMAP_NONEFOUND |
| 134 |
sprintf(errmsg, "no photons found on %s at (%.3f, %.3f, %.3f)", |
| 135 |
ray -> ro ? ray -> ro -> oname : "<null>", |
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ray -> rop [0], ray -> rop [1], ray -> rop [2]); |
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error(WARNING, errmsg); |
| 138 |
#endif |
| 139 |
|
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return; |
| 141 |
} |
| 142 |
|
| 143 |
/* Average (squared) radius between furthest two photons to improve |
| 144 |
* accuracy and get inverse search area 1 / (PI * r^2), with extra |
| 145 |
* normalisation factor 1 / PI for ambient calculation */ |
| 146 |
sq = pmap -> squeue + 1; |
| 147 |
r = max(sq -> dist, (sq + 1) -> dist); |
| 148 |
r = 0.25 * (pmap -> maxDist + r + 2 * sqrt(pmap -> maxDist * r)); |
| 149 |
invArea = 1 / (PI * PI * r); |
| 150 |
|
| 151 |
/* Skip the extra photon */ |
| 152 |
for (i = 1 ; i < pmap -> squeueEnd; i++, sq++) { |
| 153 |
COLOR flux; |
| 154 |
|
| 155 |
/* Get photon's contribution to density estimate */ |
| 156 |
getPhotonFlux(sq -> photon, flux); |
| 157 |
scalecolor(flux, invArea); |
| 158 |
#ifdef PMAP_EPANECHNIKOV |
| 159 |
/* Apply Epanechnikov kernel to photon flux (dists are squared) */ |
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scalecolor(flux, 2 * (1 - sq -> dist / r)); |
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#endif |
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addcolor(irrad, flux); |
| 163 |
|
| 164 |
if (pmap -> srcContrib) { |
| 165 |
const PhotonPrimary *primary = pmap -> primary + |
| 166 |
sq -> photon -> primary; |
| 167 |
OBJREC *srcMod = objptr(source [primary -> srcIdx].so -> omod); |
| 168 |
MODCONT *srcContrib = (MODCONT*)lu_find(pmap -> srcContrib, |
| 169 |
srcMod -> oname) -> data; |
| 170 |
|
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if (srcContrib) { |
| 172 |
/* Photon's emitting light source has modifier whose |
| 173 |
* contributions are sought */ |
| 174 |
int srcBin; |
| 175 |
|
| 176 |
/* Set incident dir and origin of photon's primary ray on |
| 177 |
* light source for dummy shadow ray, and evaluate binning |
| 178 |
* function */ |
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VCOPY(ray -> rdir, primary -> dir); |
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VCOPY(ray -> rop, primary -> org); |
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srcBin = evalue(srcContrib -> binv) + .5; |
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|
| 183 |
if (srcBin < 0 || srcBin >= srcContrib -> nbins) { |
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error(WARNING, "bad bin number (ignored)"); |
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continue; |
| 186 |
} |
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|
| 188 |
if (!contrib) { |
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/* Ray coefficient mode; normalise by light source radiance |
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* after applying distrib pattern */ |
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int j; |
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raytexture(ray, srcMod -> omod); |
| 193 |
setcolor(ray -> rcol, srcMod -> oargs.farg [0], |
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srcMod -> oargs.farg [1], srcMod -> oargs.farg [2]); |
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multcolor(ray -> rcol, ray -> pcol); |
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for (j = 0; j < 3; j++) |
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flux [j] = ray -> rcol [j] ? flux [j] / ray -> rcol [j] |
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: 0; |
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} |
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|
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multcolor(flux, rayCoeff); |
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addcolor(srcContrib -> cbin [srcBin], flux); |
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} |
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else fprintf(stderr, "Skipped contrib from %s\n", srcMod -> oname); |
| 205 |
} |
| 206 |
} |
| 207 |
|
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/* Restore incident ray's direction and hitpoint */ |
| 209 |
VCOPY(ray -> rdir, rdir); |
| 210 |
VCOPY(ray -> rop, rop); |
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|
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return; |
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} |
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|
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|
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|
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void distribPhotonContrib (PhotonMap* pm) |
| 218 |
{ |
| 219 |
EmissionMap emap; |
| 220 |
char errmsg2 [128]; |
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unsigned srcIdx; |
| 222 |
double *srcFlux; /* Emitted flux per light source */ |
| 223 |
const double srcDistribTarget = /* Target photon count per source */ |
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nsources ? (double)pm -> distribTarget / nsources : 0; |
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|
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if (!pm) |
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error(USER, "no photon map defined"); |
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|
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if (!nsources) |
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error(USER, "no light sources"); |
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|
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/* Allocate photon flux per light source; this differs for every |
| 233 |
* source as all sources contribute the same number of distributed |
| 234 |
* photons (srcDistribTarget), hence the number of photons emitted per |
| 235 |
* source does not correlate with its emitted flux. The resulting flux |
| 236 |
* per photon is therefore adjusted individually for each source. */ |
| 237 |
if (!(srcFlux = calloc(nsources, sizeof(double)))) |
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error(SYSTEM, "cannot allocate source flux"); |
| 239 |
|
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/* ================================================================ |
| 241 |
* INITIALISASHUNN - Set up emisshunn and scattering funcs |
| 242 |
* ================================================================ */ |
| 243 |
emap.samples = NULL; |
| 244 |
emap.src = NULL; |
| 245 |
emap.maxPartitions = MAXSPART; |
| 246 |
emap.partitions = (unsigned char*)malloc(emap.maxPartitions >> 1); |
| 247 |
if (!emap.partitions) |
| 248 |
error(USER, "can't allocate source partitions"); |
| 249 |
|
| 250 |
initPhotonMap(pm, PMAP_TYPE_CONTRIB); |
| 251 |
initPhotonEmissionFuncs(); |
| 252 |
initPhotonScatterFuncs(); |
| 253 |
|
| 254 |
/* Get photon ports if specified */ |
| 255 |
if (ambincl == 1) |
| 256 |
getPhotonPorts(); |
| 257 |
|
| 258 |
/* Get photon sensor modifiers */ |
| 259 |
getPhotonSensors(photonSensorList); |
| 260 |
|
| 261 |
/* Seed RNGs for photon distribution */ |
| 262 |
pmapSeed(randSeed, partState); |
| 263 |
pmapSeed(randSeed, emitState); |
| 264 |
pmapSeed(randSeed, cntState); |
| 265 |
pmapSeed(randSeed, mediumState); |
| 266 |
pmapSeed(randSeed, scatterState); |
| 267 |
pmapSeed(randSeed, rouletteState); |
| 268 |
|
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/* Record start time and enable progress report signal handler */ |
| 270 |
repStartTime = time(NULL); |
| 271 |
signal(SIGCONT, pmapDistribReport); |
| 272 |
|
| 273 |
for (srcIdx = 0; srcIdx < nsources; srcIdx++) { |
| 274 |
unsigned portCnt = 0, passCnt = 0, prePassCnt = 0; |
| 275 |
double srcNumEmit = 0; /* # photons to emit from source */ |
| 276 |
unsigned long srcNumDistrib = pm -> heapEnd; /* # photons stored */ |
| 277 |
|
| 278 |
srcFlux [srcIdx] = repProgress = 0; |
| 279 |
emap.src = source + srcIdx; |
| 280 |
|
| 281 |
if (photonRepTime) |
| 282 |
eputs("\n"); |
| 283 |
|
| 284 |
/* ============================================================= |
| 285 |
* FLUX INTEGRATION - Get total flux emitted from light source |
| 286 |
* ============================================================= */ |
| 287 |
do { |
| 288 |
emap.port = emap.src -> sflags & SDISTANT |
| 289 |
? photonPorts + portCnt : NULL; |
| 290 |
photonPartition [emap.src -> so -> otype] (&emap); |
| 291 |
|
| 292 |
if (photonRepTime) { |
| 293 |
sprintf(errmsg, "Integrating flux from source %s (mod %s) ", |
| 294 |
source [srcIdx].so -> oname, |
| 295 |
objptr(source [srcIdx].so -> omod) -> oname); |
| 296 |
|
| 297 |
if (emap.port) { |
| 298 |
sprintf(errmsg2, "via port %s ", |
| 299 |
photonPorts [portCnt].so -> oname); |
| 300 |
strcat(errmsg, errmsg2); |
| 301 |
} |
| 302 |
|
| 303 |
sprintf(errmsg2, "(%lu partitions)...\n", |
| 304 |
emap.numPartitions); |
| 305 |
strcat(errmsg, errmsg2); |
| 306 |
eputs(errmsg); |
| 307 |
fflush(stderr); |
| 308 |
} |
| 309 |
|
| 310 |
for (emap.partitionCnt = 0; |
| 311 |
emap.partitionCnt < emap.numPartitions; |
| 312 |
emap.partitionCnt++) { |
| 313 |
initPhotonEmission(&emap, pdfSamples); |
| 314 |
srcFlux [srcIdx] += colorAvg(emap.partFlux); |
| 315 |
} |
| 316 |
|
| 317 |
portCnt++; |
| 318 |
} while (portCnt < numPhotonPorts); |
| 319 |
|
| 320 |
if (srcFlux [srcIdx] < FTINY) { |
| 321 |
sprintf(errmsg, "source %s has zero emission", |
| 322 |
source [srcIdx].so -> oname); |
| 323 |
error(WARNING, errmsg); |
| 324 |
} |
| 325 |
else { |
| 326 |
/* ========================================================== |
| 327 |
* 2-PASS PHOTON DISTRIBUTION |
| 328 |
* Pass 1 (pre): emit fraction of target photon count |
| 329 |
* Pass 2 (main): based on outcome of pass 1, estimate |
| 330 |
* remaining number of photons to emit to |
| 331 |
* approximate target count |
| 332 |
* ========================================================== */ |
| 333 |
do { |
| 334 |
if (!passCnt) { |
| 335 |
/* INIT PASS 1 */ |
| 336 |
if (++prePassCnt > maxPreDistrib) { |
| 337 |
/* Warn if no photons contributed after sufficient |
| 338 |
* iterations */ |
| 339 |
sprintf(errmsg, "too many prepasses, no photons " |
| 340 |
"from source %s", source [srcIdx].so -> oname); |
| 341 |
error(WARNING, errmsg); |
| 342 |
break; |
| 343 |
} |
| 344 |
|
| 345 |
/* Num to emit is fraction of target count */ |
| 346 |
srcNumEmit = preDistrib * srcDistribTarget; |
| 347 |
} |
| 348 |
|
| 349 |
else { |
| 350 |
/* INIT PASS 2 */ |
| 351 |
/* Based on the outcome of the predistribution we can now |
| 352 |
* figure out how many more photons we have to emit from |
| 353 |
* the current source to meet the target count, |
| 354 |
* srcDistribTarget. This value is clamped to 0 in case |
| 355 |
* the target has already been exceeded in pass 1. |
| 356 |
* srcNumEmit and srcNumDistrib is the number of photons |
| 357 |
* emitted and distributed (stored) from the current |
| 358 |
* source in pass 1, respectively. */ |
| 359 |
srcNumDistrib = pm -> heapEnd - srcNumDistrib; |
| 360 |
srcNumEmit *= srcNumDistrib |
| 361 |
? max(srcDistribTarget/srcNumDistrib, 1) - 1 |
| 362 |
: 0; |
| 363 |
|
| 364 |
if (!srcNumEmit) |
| 365 |
/* No photons left to distribute in main pass */ |
| 366 |
break; |
| 367 |
} |
| 368 |
|
| 369 |
/* Set completion count for progress report */ |
| 370 |
repComplete = srcNumEmit + repProgress; |
| 371 |
portCnt = 0; |
| 372 |
|
| 373 |
do { |
| 374 |
emap.port = emap.src -> sflags & SDISTANT |
| 375 |
? photonPorts + portCnt : NULL; |
| 376 |
photonPartition [emap.src -> so -> otype] (&emap); |
| 377 |
|
| 378 |
if (photonRepTime) { |
| 379 |
if (!passCnt) |
| 380 |
sprintf(errmsg, "PREPASS %d on source %s (mod %s) ", |
| 381 |
prePassCnt, source [srcIdx].so -> oname, |
| 382 |
objptr(source[srcIdx].so->omod) -> oname); |
| 383 |
else |
| 384 |
sprintf(errmsg, "MAIN PASS on source %s (mod %s) ", |
| 385 |
source [srcIdx].so -> oname, |
| 386 |
objptr(source[srcIdx].so->omod) -> oname); |
| 387 |
|
| 388 |
if (emap.port) { |
| 389 |
sprintf(errmsg2, "via port %s ", |
| 390 |
photonPorts [portCnt].so -> oname); |
| 391 |
strcat(errmsg, errmsg2); |
| 392 |
} |
| 393 |
|
| 394 |
sprintf(errmsg2, "(%lu partitions)...\n", |
| 395 |
emap.numPartitions); |
| 396 |
strcat(errmsg, errmsg2); |
| 397 |
eputs(errmsg); |
| 398 |
fflush(stderr); |
| 399 |
} |
| 400 |
|
| 401 |
for (emap.partitionCnt = 0; |
| 402 |
emap.partitionCnt < emap.numPartitions; |
| 403 |
emap.partitionCnt++) { |
| 404 |
double partNumEmit; |
| 405 |
unsigned long partEmitCnt; |
| 406 |
|
| 407 |
/* Get photon origin within current source partishunn |
| 408 |
* and build emission map */ |
| 409 |
photonOrigin [emap.src -> so -> otype] (&emap); |
| 410 |
initPhotonEmission(&emap, pdfSamples); |
| 411 |
|
| 412 |
/* Number of photons to emit from ziss partishunn; |
| 413 |
* scale according to its normalised contribushunn to |
| 414 |
* the emitted source flux */ |
| 415 |
partNumEmit = srcNumEmit * colorAvg(emap.partFlux) / |
| 416 |
srcFlux [srcIdx]; |
| 417 |
partEmitCnt = (unsigned long)partNumEmit; |
| 418 |
|
| 419 |
/* Probabilistically account for fractional photons */ |
| 420 |
if (pmapRandom(cntState) < partNumEmit - partEmitCnt) |
| 421 |
partEmitCnt++; |
| 422 |
|
| 423 |
/* Integer counter avoids FP rounding errors */ |
| 424 |
while (partEmitCnt--) { |
| 425 |
RAY photonRay; |
| 426 |
|
| 427 |
/* Emit photon according to PDF (if any), allocate |
| 428 |
* associated primary ray, and trace through scene |
| 429 |
* until absorbed/leaked */ |
| 430 |
emitPhoton(&emap, &photonRay); |
| 431 |
addPhotonPrimary(pm, &photonRay); |
| 432 |
tracePhoton(&photonRay); |
| 433 |
|
| 434 |
/* Record progress */ |
| 435 |
repProgress++; |
| 436 |
|
| 437 |
if (photonRepTime > 0 && |
| 438 |
time(NULL) >= repLastTime + photonRepTime) |
| 439 |
pmapDistribReport(); |
| 440 |
#ifndef BSD |
| 441 |
else signal(SIGCONT, pmapDistribReport); |
| 442 |
#endif |
| 443 |
} |
| 444 |
} |
| 445 |
|
| 446 |
portCnt++; |
| 447 |
} while (portCnt < numPhotonPorts); |
| 448 |
|
| 449 |
if (pm -> heapEnd == srcNumDistrib) |
| 450 |
/* Double preDistrib in case no photons were stored |
| 451 |
* for this source and redo pass 1 */ |
| 452 |
preDistrib *= 2; |
| 453 |
else { |
| 454 |
/* Now do pass 2 */ |
| 455 |
passCnt++; |
| 456 |
if (photonRepTime) |
| 457 |
eputs("\n"); |
| 458 |
} |
| 459 |
} while (passCnt < 2); |
| 460 |
|
| 461 |
/* Flux per photon emitted from this source; repProgress is the |
| 462 |
* number of emitted photons after both passes */ |
| 463 |
srcFlux [srcIdx] = repProgress ? srcFlux [srcIdx] / repProgress |
| 464 |
: 0; |
| 465 |
} |
| 466 |
} |
| 467 |
|
| 468 |
/* ================================================================ |
| 469 |
* POST-DISTRIBUTION - Set photon flux and build kd-tree, etc. |
| 470 |
* ================================================================ */ |
| 471 |
signal(SIGCONT, SIG_DFL); |
| 472 |
free(emap.samples); |
| 473 |
|
| 474 |
if (!pm -> heapEnd) |
| 475 |
error(USER, "empty photon map"); |
| 476 |
|
| 477 |
/* Check for valid primary photon rays */ |
| 478 |
if (!pm -> primary) |
| 479 |
error(INTERNAL, "no primary rays in contribution photon map"); |
| 480 |
|
| 481 |
if (pm -> primary [pm -> primaryEnd].srcIdx < 0) |
| 482 |
/* Last primary ray is unused, so decrement counter */ |
| 483 |
pm -> primaryEnd--; |
| 484 |
|
| 485 |
if (photonRepTime) { |
| 486 |
eputs("\nBuilding contrib photon heap...\n"); |
| 487 |
fflush(stderr); |
| 488 |
} |
| 489 |
|
| 490 |
balancePhotons(pm, srcFlux); |
| 491 |
} |
