1 |
#ifndef lint |
2 |
static const char RCSid[] = "$Id: pmap.c,v 2.9 2015/08/18 18:45:55 greg Exp $"; |
3 |
#endif |
4 |
/* |
5 |
================================================================== |
6 |
Photon map main module |
7 |
|
8 |
Roland Schregle (roland.schregle@{hslu.ch, gmail.com}) |
9 |
(c) Fraunhofer Institute for Solar Energy Systems, |
10 |
(c) Lucerne University of Applied Sciences and Arts, |
11 |
supported by the Swiss National Science Foundation (SNSF, #147053) |
12 |
================================================================== |
13 |
|
14 |
*/ |
15 |
|
16 |
|
17 |
|
18 |
#include "pmap.h" |
19 |
#include "pmapmat.h" |
20 |
#include "pmapsrc.h" |
21 |
#include "pmaprand.h" |
22 |
#include "pmapio.h" |
23 |
#include "pmapbias.h" |
24 |
#include "pmapdiag.h" |
25 |
#include "otypes.h" |
26 |
#include <time.h> |
27 |
#include <sys/stat.h> |
28 |
|
29 |
|
30 |
|
31 |
extern char *octname; |
32 |
|
33 |
static char PmapRevision [] = "$Revision: 2.9 $"; |
34 |
|
35 |
|
36 |
|
37 |
/* Photon map lookup functions per type */ |
38 |
void (*pmapLookup [NUM_PMAP_TYPES])(PhotonMap*, RAY*, COLOR) = { |
39 |
photonDensity, photonPreCompDensity, photonDensity, volumePhotonDensity, |
40 |
photonDensity, NULL |
41 |
}; |
42 |
|
43 |
|
44 |
|
45 |
void colorNorm (COLOR c) |
46 |
/* Normalise colour channels to average of 1 */ |
47 |
{ |
48 |
const float avg = colorAvg(c); |
49 |
|
50 |
if (!avg) |
51 |
return; |
52 |
|
53 |
c [0] /= avg; |
54 |
c [1] /= avg; |
55 |
c [2] /= avg; |
56 |
} |
57 |
|
58 |
|
59 |
|
60 |
void loadPmaps (PhotonMap **pmaps, const PhotonMapParams *parm) |
61 |
{ |
62 |
unsigned t; |
63 |
struct stat octstat, pmstat; |
64 |
PhotonMap *pm; |
65 |
PhotonMapType type; |
66 |
|
67 |
for (t = 0; t < NUM_PMAP_TYPES; t++) |
68 |
if (setPmapParam(&pm, parm + t)) { |
69 |
/* Check if photon map newer than octree */ |
70 |
if (pm -> fileName && octname && |
71 |
!stat(pm -> fileName, &pmstat) && !stat(octname, &octstat) && |
72 |
octstat.st_mtime > pmstat.st_mtime) { |
73 |
sprintf(errmsg, "photon map in file %s may be stale", |
74 |
pm -> fileName); |
75 |
error(USER, errmsg); |
76 |
} |
77 |
|
78 |
/* Load photon map from file and get its type */ |
79 |
if ((type = loadPhotonMap(pm, pm -> fileName)) == PMAP_TYPE_NONE) |
80 |
error(USER, "failed loading photon map"); |
81 |
|
82 |
/* Assign to appropriate photon map type (deleting previously |
83 |
* loaded photon map of same type if necessary) */ |
84 |
if (pmaps [type]) { |
85 |
deletePhotons(pmaps [type]); |
86 |
free(pmaps [type]); |
87 |
} |
88 |
pmaps [type] = pm; |
89 |
|
90 |
/* Check for invalid density estimate bandwidth */ |
91 |
if (pm -> maxGather > pm -> heapSize) { |
92 |
error(WARNING, "adjusting density estimate bandwidth"); |
93 |
pm -> minGather = pm -> maxGather = pm -> heapSize; |
94 |
} |
95 |
} |
96 |
} |
97 |
|
98 |
|
99 |
|
100 |
void savePmaps (const PhotonMap **pmaps, int argc, char **argv) |
101 |
{ |
102 |
unsigned t; |
103 |
|
104 |
for (t = 0; t < NUM_PMAP_TYPES; t++) { |
105 |
if (pmaps [t]) |
106 |
savePhotonMap(pmaps [t], pmaps [t] -> fileName, argc, argv); |
107 |
} |
108 |
} |
109 |
|
110 |
|
111 |
|
112 |
void cleanUpPmaps (PhotonMap **pmaps) |
113 |
{ |
114 |
unsigned t; |
115 |
|
116 |
for (t = 0; t < NUM_PMAP_TYPES; t++) { |
117 |
if (pmaps [t]) { |
118 |
deletePhotons(pmaps [t]); |
119 |
free(pmaps [t]); |
120 |
} |
121 |
} |
122 |
} |
123 |
|
124 |
|
125 |
|
126 |
static int photonParticipate (RAY *ray) |
127 |
/* Trace photon through participating medium. Returns 1 if passed through, |
128 |
or 0 if absorbed and $*%&ed. Analogon to rayparticipate(). */ |
129 |
{ |
130 |
int i; |
131 |
RREAL cosTheta, cosPhi, du, dv; |
132 |
const float cext = colorAvg(ray -> cext), |
133 |
albedo = colorAvg(ray -> albedo); |
134 |
FVECT u, v; |
135 |
COLOR cvext; |
136 |
|
137 |
/* Mean free distance until interaction with medium */ |
138 |
ray -> rmax = -log(pmapRandom(mediumState)) / cext; |
139 |
|
140 |
while (!localhit(ray, &thescene)) { |
141 |
setcolor(cvext, exp(-ray -> rmax * ray -> cext [0]), |
142 |
exp(-ray -> rmax * ray -> cext [1]), |
143 |
exp(-ray -> rmax * ray -> cext [2])); |
144 |
|
145 |
/* Modify ray color and normalise */ |
146 |
multcolor(ray -> rcol, cvext); |
147 |
colorNorm(ray -> rcol); |
148 |
VCOPY(ray -> rorg, ray -> rop); |
149 |
|
150 |
if (albedo > FTINY) |
151 |
/* Add to volume photon map */ |
152 |
if (ray -> rlvl > 0) addPhoton(volumePmap, ray); |
153 |
|
154 |
/* Absorbed? */ |
155 |
if (pmapRandom(rouletteState) > albedo) return 0; |
156 |
|
157 |
/* Colour bleeding without attenuation (?) */ |
158 |
multcolor(ray -> rcol, ray -> albedo); |
159 |
scalecolor(ray -> rcol, 1 / albedo); |
160 |
|
161 |
/* Scatter photon */ |
162 |
cosTheta = ray -> gecc <= FTINY ? 2 * pmapRandom(scatterState) - 1 |
163 |
: 1 / (2 * ray -> gecc) * |
164 |
(1 + ray -> gecc * ray -> gecc - |
165 |
(1 - ray -> gecc * ray -> gecc) / |
166 |
(1 - ray -> gecc + 2 * ray -> gecc * |
167 |
pmapRandom(scatterState))); |
168 |
|
169 |
cosPhi = cos(2 * PI * pmapRandom(scatterState)); |
170 |
du = dv = sqrt(1 - cosTheta * cosTheta); /* sin(theta) */ |
171 |
du *= cosPhi; |
172 |
dv *= sqrt(1 - cosPhi * cosPhi); /* sin(phi) */ |
173 |
|
174 |
/* Get axes u & v perpendicular to photon direction */ |
175 |
i = 0; |
176 |
do { |
177 |
v [0] = v [1] = v [2] = 0; |
178 |
v [i++] = 1; |
179 |
fcross(u, v, ray -> rdir); |
180 |
} while (normalize(u) < FTINY); |
181 |
fcross(v, ray -> rdir, u); |
182 |
|
183 |
for (i = 0; i < 3; i++) |
184 |
ray -> rdir [i] = du * u [i] + dv * v [i] + |
185 |
cosTheta * ray -> rdir [i]; |
186 |
ray -> rlvl++; |
187 |
ray -> rmax = -log(pmapRandom(mediumState)) / cext; |
188 |
} |
189 |
|
190 |
setcolor(cvext, exp(-ray -> rot * ray -> cext [0]), |
191 |
exp(-ray -> rot * ray -> cext [1]), |
192 |
exp(-ray -> rot * ray -> cext [2])); |
193 |
|
194 |
/* Modify ray color and normalise */ |
195 |
multcolor(ray -> rcol, cvext); |
196 |
colorNorm(ray -> rcol); |
197 |
|
198 |
/* Passed through medium */ |
199 |
return 1; |
200 |
} |
201 |
|
202 |
|
203 |
|
204 |
void tracePhoton (RAY *ray) |
205 |
/* Follow photon as it bounces around... */ |
206 |
{ |
207 |
long mod; |
208 |
OBJREC* mat; |
209 |
|
210 |
if (ray -> rlvl > photonMaxBounce) { |
211 |
#ifdef PMAP_RUNAWAY_WARN |
212 |
error(WARNING, "runaway photon!"); |
213 |
#endif |
214 |
return; |
215 |
} |
216 |
|
217 |
if (colorAvg(ray -> cext) > FTINY && !photonParticipate(ray)) |
218 |
return; |
219 |
|
220 |
if (localhit(ray, &thescene)) { |
221 |
mod = ray -> ro -> omod; |
222 |
|
223 |
if ((ray -> clipset && inset(ray -> clipset, mod)) || mod == OVOID) { |
224 |
/* Transfer ray if modifier is VOID or clipped within antimatta */ |
225 |
RAY tray; |
226 |
photonRay(ray, &tray, PMAP_XFER, NULL); |
227 |
tracePhoton(&tray); |
228 |
} |
229 |
else { |
230 |
/* Scatter for modifier material */ |
231 |
mat = objptr(mod); |
232 |
photonScatter [mat -> otype] (mat, ray); |
233 |
} |
234 |
} |
235 |
} |
236 |
|
237 |
|
238 |
|
239 |
static void preComputeGlobal (PhotonMap *pmap) |
240 |
/* Precompute irradiance from global photons for final gathering using |
241 |
the first finalGather * pmap -> heapSize photons in the heap. Returns |
242 |
new heap with precomputed photons. */ |
243 |
{ |
244 |
unsigned long i, nuHeapSize; |
245 |
unsigned j; |
246 |
Photon *nuHeap, *p; |
247 |
COLOR irrad; |
248 |
RAY ray; |
249 |
float nuMinPos [3], nuMaxPos [3]; |
250 |
|
251 |
repComplete = nuHeapSize = finalGather * pmap -> heapSize; |
252 |
|
253 |
if (photonRepTime) { |
254 |
sprintf(errmsg, |
255 |
"Precomputing irradiance for %ld global photons...\n", |
256 |
nuHeapSize); |
257 |
eputs(errmsg); |
258 |
fflush(stderr); |
259 |
} |
260 |
|
261 |
p = nuHeap = (Photon*)malloc(nuHeapSize * sizeof(Photon)); |
262 |
if (!nuHeap) |
263 |
error(USER, "can't allocate photon heap"); |
264 |
|
265 |
for (j = 0; j <= 2; j++) { |
266 |
nuMinPos [j] = FHUGE; |
267 |
nuMaxPos [j] = -FHUGE; |
268 |
} |
269 |
|
270 |
/* Record start time, baby */ |
271 |
repStartTime = time(NULL); |
272 |
#ifdef SIGCONT |
273 |
signal(SIGCONT, pmapPreCompReport); |
274 |
#endif |
275 |
repProgress = 0; |
276 |
memcpy(nuHeap, pmap -> heap, nuHeapSize * sizeof(Photon)); |
277 |
|
278 |
for (i = 0, p = nuHeap; i < nuHeapSize; i++, p++) { |
279 |
ray.ro = NULL; |
280 |
VCOPY(ray.rop, p -> pos); |
281 |
|
282 |
/* Update min and max positions & set ray normal */ |
283 |
for (j = 0; j < 3; j++) { |
284 |
if (p -> pos [j] < nuMinPos [j]) nuMinPos [j] = p -> pos [j]; |
285 |
if (p -> pos [j] > nuMaxPos [j]) nuMaxPos [j] = p -> pos [j]; |
286 |
ray.ron [j] = p -> norm [j] / 127.0; |
287 |
} |
288 |
|
289 |
photonDensity(pmap, &ray, irrad); |
290 |
setPhotonFlux(p, irrad); |
291 |
repProgress++; |
292 |
|
293 |
if (photonRepTime > 0 && time(NULL) >= repLastTime + photonRepTime) |
294 |
pmapPreCompReport(); |
295 |
#ifdef SIGCONT |
296 |
else signal(SIGCONT, pmapPreCompReport); |
297 |
#endif |
298 |
} |
299 |
|
300 |
#ifdef SIGCONT |
301 |
signal(SIGCONT, SIG_DFL); |
302 |
#endif |
303 |
|
304 |
/* Replace & rebuild heap */ |
305 |
free(pmap -> heap); |
306 |
pmap -> heap = nuHeap; |
307 |
pmap -> heapSize = pmap -> heapEnd = nuHeapSize; |
308 |
VCOPY(pmap -> minPos, nuMinPos); |
309 |
VCOPY(pmap -> maxPos, nuMaxPos); |
310 |
|
311 |
if (photonRepTime) { |
312 |
eputs("Rebuilding global photon heap...\n"); |
313 |
fflush(stderr); |
314 |
} |
315 |
|
316 |
balancePhotons(pmap, NULL); |
317 |
} |
318 |
|
319 |
|
320 |
|
321 |
void distribPhotons (PhotonMap **pmaps) |
322 |
{ |
323 |
EmissionMap emap; |
324 |
char errmsg2 [128]; |
325 |
unsigned t, srcIdx, passCnt = 0, prePassCnt = 0; |
326 |
double totalFlux = 0; |
327 |
PhotonMap *pm; |
328 |
|
329 |
for (t = 0; t < NUM_PMAP_TYPES && !pmaps [t]; t++); |
330 |
if (t >= NUM_PMAP_TYPES) |
331 |
error(USER, "no photon maps defined"); |
332 |
|
333 |
if (!nsources) |
334 |
error(USER, "no light sources"); |
335 |
|
336 |
/* =================================================================== |
337 |
* INITIALISATION - Set up emission and scattering funcs |
338 |
* =================================================================== */ |
339 |
emap.samples = NULL; |
340 |
emap.maxPartitions = MAXSPART; |
341 |
emap.partitions = (unsigned char*)malloc(emap.maxPartitions >> 1); |
342 |
if (!emap.partitions) |
343 |
error(INTERNAL, "can't allocate source partitions"); |
344 |
|
345 |
/* Initialise all defined photon maps */ |
346 |
for (t = 0; t < NUM_PMAP_TYPES; t++) |
347 |
initPhotonMap(pmaps [t], t); |
348 |
|
349 |
initPhotonEmissionFuncs(); |
350 |
initPhotonScatterFuncs(); |
351 |
|
352 |
/* Get photon ports if specified */ |
353 |
if (ambincl == 1) |
354 |
getPhotonPorts(); |
355 |
|
356 |
/* Get photon sensor modifiers */ |
357 |
getPhotonSensors(photonSensorList); |
358 |
|
359 |
/* Seed RNGs for photon distribution */ |
360 |
pmapSeed(randSeed, partState); |
361 |
pmapSeed(randSeed, emitState); |
362 |
pmapSeed(randSeed, cntState); |
363 |
pmapSeed(randSeed, mediumState); |
364 |
pmapSeed(randSeed, scatterState); |
365 |
pmapSeed(randSeed, rouletteState); |
366 |
|
367 |
if (photonRepTime) |
368 |
eputs("\n"); |
369 |
|
370 |
/* =================================================================== |
371 |
* FLUX INTEGRATION - Get total photon flux from light sources |
372 |
* =================================================================== */ |
373 |
for (srcIdx = 0; srcIdx < nsources; srcIdx++) { |
374 |
unsigned portCnt = 0; |
375 |
emap.src = source + srcIdx; |
376 |
|
377 |
do { |
378 |
emap.port = emap.src -> sflags & SDISTANT ? photonPorts + portCnt |
379 |
: NULL; |
380 |
photonPartition [emap.src -> so -> otype] (&emap); |
381 |
|
382 |
if (photonRepTime) { |
383 |
sprintf(errmsg, "Integrating flux from source %s ", |
384 |
source [srcIdx].so -> oname); |
385 |
|
386 |
if (emap.port) { |
387 |
sprintf(errmsg2, "via port %s ", |
388 |
photonPorts [portCnt].so -> oname); |
389 |
strcat(errmsg, errmsg2); |
390 |
} |
391 |
|
392 |
sprintf(errmsg2, "(%lu partitions)...\n", emap.numPartitions); |
393 |
strcat(errmsg, errmsg2); |
394 |
eputs(errmsg); |
395 |
fflush(stderr); |
396 |
} |
397 |
|
398 |
for (emap.partitionCnt = 0; emap.partitionCnt < emap.numPartitions; |
399 |
emap.partitionCnt++) { |
400 |
initPhotonEmission(&emap, pdfSamples); |
401 |
totalFlux += colorAvg(emap.partFlux); |
402 |
} |
403 |
|
404 |
portCnt++; |
405 |
} while (portCnt < numPhotonPorts); |
406 |
} |
407 |
|
408 |
if (totalFlux < FTINY) |
409 |
error(USER, "zero flux from light sources"); |
410 |
|
411 |
/* Record start time and enable progress report signal handler */ |
412 |
repStartTime = time(NULL); |
413 |
#ifdef SIGCONT |
414 |
signal(SIGCONT, pmapDistribReport); |
415 |
#endif |
416 |
repProgress = prePassCnt = 0; |
417 |
|
418 |
if (photonRepTime) |
419 |
eputs("\n"); |
420 |
|
421 |
/* =================================================================== |
422 |
* 2-PASS PHOTON DISTRIBUTION |
423 |
* Pass 1 (pre): emit fraction of target photon count |
424 |
* Pass 2 (main): based on outcome of pass 1, estimate remaining number |
425 |
* of photons to emit to approximate target count |
426 |
* =================================================================== */ |
427 |
do { |
428 |
double numEmit; |
429 |
|
430 |
if (!passCnt) { |
431 |
/* INIT PASS 1 */ |
432 |
/* Skip if no photons contributed after sufficient iterations; make |
433 |
* it clear to user which photon maps are missing so (s)he can |
434 |
* check the scene geometry and materials */ |
435 |
if (++prePassCnt > maxPreDistrib) { |
436 |
sprintf(errmsg, "too many prepasses"); |
437 |
|
438 |
for (t = 0; t < NUM_PMAP_TYPES; t++) |
439 |
if (pmaps [t] && !pmaps [t] -> heapEnd) { |
440 |
sprintf(errmsg2, ", no %s photons stored", pmapName [t]); |
441 |
strcat(errmsg, errmsg2); |
442 |
} |
443 |
|
444 |
error(USER, errmsg); |
445 |
break; |
446 |
} |
447 |
|
448 |
/* Num to emit is fraction of minimum target count */ |
449 |
numEmit = FHUGE; |
450 |
|
451 |
for (t = 0; t < NUM_PMAP_TYPES; t++) |
452 |
if (pmaps [t]) |
453 |
numEmit = min(pmaps [t] -> distribTarget, numEmit); |
454 |
|
455 |
numEmit *= preDistrib; |
456 |
} |
457 |
|
458 |
else { |
459 |
/* INIT PASS 2 */ |
460 |
/* Based on the outcome of the predistribution we can now estimate |
461 |
* how many more photons we have to emit for each photon map to |
462 |
* meet its respective target count. This value is clamped to 0 in |
463 |
* case the target has already been exceeded in the pass 1. Note |
464 |
* repProgress is the number of photons emitted thus far, while |
465 |
* heapEnd is the number of photons stored in each photon map. */ |
466 |
double maxDistribRatio = 0; |
467 |
|
468 |
/* Set the distribution ratio for each map; this indicates how many |
469 |
* photons of each respective type are stored per emitted photon, |
470 |
* and is used as probability for storing a photon by addPhoton(). |
471 |
* Since this biases the photon density, addPhoton() promotes the |
472 |
* flux of stored photons to compensate. */ |
473 |
for (t = 0; t < NUM_PMAP_TYPES; t++) |
474 |
if ((pm = pmaps [t])) { |
475 |
pm -> distribRatio = (double)pm -> distribTarget / |
476 |
pm -> heapEnd - 1; |
477 |
|
478 |
/* Check if photon map "overflowed", i.e. exceeded its target |
479 |
* count in the prepass; correcting the photon flux via the |
480 |
* distribution ratio is no longer possible, as no more |
481 |
* photons of this type will be stored, so notify the user |
482 |
* rather than deliver incorrect results. |
483 |
* In future we should handle this more intelligently by |
484 |
* using the photonFlux in each photon map to individually |
485 |
* correct the flux after distribution. */ |
486 |
if (pm -> distribRatio <= FTINY) { |
487 |
sprintf(errmsg, |
488 |
"%s photon map overflow in prepass, reduce -apD", |
489 |
pmapName [t]); |
490 |
error(INTERNAL, errmsg); |
491 |
} |
492 |
|
493 |
maxDistribRatio = max(pm -> distribRatio, maxDistribRatio); |
494 |
} |
495 |
|
496 |
/* Normalise distribution ratios and calculate number of photons to |
497 |
* emit in main pass */ |
498 |
for (t = 0; t < NUM_PMAP_TYPES; t++) |
499 |
if ((pm = pmaps [t])) |
500 |
pm -> distribRatio /= maxDistribRatio; |
501 |
|
502 |
if ((numEmit = repProgress * maxDistribRatio) < FTINY) |
503 |
/* No photons left to distribute in main pass */ |
504 |
break; |
505 |
} |
506 |
|
507 |
/* Set completion count for progress report */ |
508 |
repComplete = numEmit + repProgress; |
509 |
|
510 |
/* PHOTON DISTRIBUTION LOOP */ |
511 |
for (srcIdx = 0; srcIdx < nsources; srcIdx++) { |
512 |
unsigned portCnt = 0; |
513 |
emap.src = source + srcIdx; |
514 |
|
515 |
do { |
516 |
emap.port = emap.src -> sflags & SDISTANT ? photonPorts + portCnt |
517 |
: NULL; |
518 |
photonPartition [emap.src -> so -> otype] (&emap); |
519 |
|
520 |
if (photonRepTime) { |
521 |
if (!passCnt) |
522 |
sprintf(errmsg, "PREPASS %d on source %s ", |
523 |
prePassCnt, source [srcIdx].so -> oname); |
524 |
else |
525 |
sprintf(errmsg, "MAIN PASS on source %s ", |
526 |
source [srcIdx].so -> oname); |
527 |
|
528 |
if (emap.port) { |
529 |
sprintf(errmsg2, "via port %s ", |
530 |
photonPorts [portCnt].so -> oname); |
531 |
strcat(errmsg, errmsg2); |
532 |
} |
533 |
|
534 |
sprintf(errmsg2, "(%lu partitions)...\n", emap.numPartitions); |
535 |
strcat(errmsg, errmsg2); |
536 |
eputs(errmsg); |
537 |
fflush(stderr); |
538 |
} |
539 |
|
540 |
for (emap.partitionCnt = 0; emap.partitionCnt < emap.numPartitions; |
541 |
emap.partitionCnt++) { |
542 |
double partNumEmit; |
543 |
unsigned long partEmitCnt; |
544 |
|
545 |
/* Get photon origin within current source partishunn and |
546 |
* build emission map */ |
547 |
photonOrigin [emap.src -> so -> otype] (&emap); |
548 |
initPhotonEmission(&emap, pdfSamples); |
549 |
|
550 |
/* Number of photons to emit from ziss partishunn -- |
551 |
* proportional to flux; photon ray weight and scalar flux |
552 |
* are uniform (the latter only varying in RGB). */ |
553 |
partNumEmit = numEmit * colorAvg(emap.partFlux) / totalFlux; |
554 |
partEmitCnt = (unsigned long)partNumEmit; |
555 |
|
556 |
/* Probabilistically account for fractional photons */ |
557 |
if (pmapRandom(cntState) < partNumEmit - partEmitCnt) |
558 |
partEmitCnt++; |
559 |
|
560 |
/* Integer counter avoids FP rounding errors */ |
561 |
while (partEmitCnt--) { |
562 |
RAY photonRay; |
563 |
|
564 |
/* Emit photon based on PDF and trace through scene until |
565 |
* absorbed/leaked */ |
566 |
emitPhoton(&emap, &photonRay); |
567 |
tracePhoton(&photonRay); |
568 |
|
569 |
/* Record progress */ |
570 |
repProgress++; |
571 |
|
572 |
if (photonRepTime > 0 && |
573 |
time(NULL) >= repLastTime + photonRepTime) |
574 |
pmapDistribReport(); |
575 |
#ifdef SIGCONT |
576 |
else signal(SIGCONT, pmapDistribReport); |
577 |
#endif |
578 |
} |
579 |
} |
580 |
|
581 |
portCnt++; |
582 |
} while (portCnt < numPhotonPorts); |
583 |
} |
584 |
|
585 |
for (t = 0; t < NUM_PMAP_TYPES; t++) |
586 |
if (pmaps [t] && !pmaps [t] -> heapEnd) { |
587 |
/* Double preDistrib in case a photon map is empty and redo |
588 |
* pass 1 --> possibility of infinite loop for pathological |
589 |
* scenes (e.g. absorbing materials) */ |
590 |
preDistrib *= 2; |
591 |
break; |
592 |
} |
593 |
|
594 |
if (t >= NUM_PMAP_TYPES) { |
595 |
/* No empty photon maps found; now do pass 2 */ |
596 |
passCnt++; |
597 |
if (photonRepTime) |
598 |
eputs("\n"); |
599 |
} |
600 |
} while (passCnt < 2); |
601 |
|
602 |
/* =================================================================== |
603 |
* POST-DISTRIBUTION - Set photon flux and build kd-tree, etc. |
604 |
* =================================================================== */ |
605 |
#ifdef SIGCONT |
606 |
signal(SIGCONT, SIG_DFL); |
607 |
#endif |
608 |
free(emap.samples); |
609 |
|
610 |
/* Set photon flux (repProgress is total num emitted) */ |
611 |
totalFlux /= repProgress; |
612 |
|
613 |
for (t = 0; t < NUM_PMAP_TYPES; t++) |
614 |
if (pmaps [t]) { |
615 |
if (photonRepTime) { |
616 |
sprintf(errmsg, "\nBuilding %s photon map...\n", pmapName [t]); |
617 |
eputs(errmsg); |
618 |
fflush(stderr); |
619 |
} |
620 |
|
621 |
balancePhotons(pmaps [t], &totalFlux); |
622 |
} |
623 |
|
624 |
/* Precompute photon irradiance if necessary */ |
625 |
if (preCompPmap) |
626 |
preComputeGlobal(preCompPmap); |
627 |
} |
628 |
|
629 |
|
630 |
|
631 |
void photonDensity (PhotonMap *pmap, RAY *ray, COLOR irrad) |
632 |
/* Photon density estimate. Returns irradiance at ray -> rop. */ |
633 |
{ |
634 |
unsigned i; |
635 |
PhotonSQNode *sq; |
636 |
float r; |
637 |
COLOR flux; |
638 |
|
639 |
setcolor(irrad, 0, 0, 0); |
640 |
|
641 |
if (!pmap -> maxGather) |
642 |
return; |
643 |
|
644 |
/* Ignore sources */ |
645 |
if (ray -> ro) |
646 |
if (islight(objptr(ray -> ro -> omod) -> otype)) |
647 |
return; |
648 |
|
649 |
pmap -> squeueEnd = 0; |
650 |
findPhotons(pmap, ray); |
651 |
|
652 |
/* Need at least 2 photons */ |
653 |
if (pmap -> squeueEnd < 2) { |
654 |
#ifdef PMAP_NONEFOUND |
655 |
sprintf(errmsg, "no photons found on %s at (%.3f, %.3f, %.3f)", |
656 |
ray -> ro ? ray -> ro -> oname : "<null>", |
657 |
ray -> rop [0], ray -> rop [1], ray -> rop [2]); |
658 |
error(WARNING, errmsg); |
659 |
#endif |
660 |
|
661 |
return; |
662 |
} |
663 |
|
664 |
if (pmap -> minGather == pmap -> maxGather) { |
665 |
/* No bias compensation. Just do a plain vanilla estimate */ |
666 |
sq = pmap -> squeue + 1; |
667 |
|
668 |
/* Average radius between furthest two photons to improve accuracy */ |
669 |
r = max(sq -> dist, (sq + 1) -> dist); |
670 |
r = 0.25 * (pmap -> maxDist + r + 2 * sqrt(pmap -> maxDist * r)); |
671 |
|
672 |
/* Skip the extra photon */ |
673 |
for (i = 1 ; i < pmap -> squeueEnd; i++, sq++) { |
674 |
getPhotonFlux(sq -> photon, flux); |
675 |
#ifdef PMAP_EPANECHNIKOV |
676 |
/* Apply Epanechnikov kernel to photon flux (dists are squared) */ |
677 |
scalecolor(flux, 2 * (1 - sq -> dist / r)); |
678 |
#endif |
679 |
addcolor(irrad, flux); |
680 |
} |
681 |
|
682 |
/* Divide by search area PI * r^2, 1 / PI required as ambient |
683 |
normalisation factor */ |
684 |
scalecolor(irrad, 1 / (PI * PI * r)); |
685 |
|
686 |
return; |
687 |
} |
688 |
else |
689 |
/* Apply bias compensation to density estimate */ |
690 |
biasComp(pmap, irrad); |
691 |
} |
692 |
|
693 |
|
694 |
|
695 |
void photonPreCompDensity (PhotonMap *pmap, RAY *r, COLOR irrad) |
696 |
/* Returns precomputed photon density estimate at ray -> rop. */ |
697 |
{ |
698 |
Photon *p; |
699 |
|
700 |
setcolor(irrad, 0, 0, 0); |
701 |
|
702 |
/* Ignore sources */ |
703 |
if (r -> ro && islight(objptr(r -> ro -> omod) -> otype)) |
704 |
return; |
705 |
|
706 |
if ((p = find1Photon(preCompPmap, r))) |
707 |
getPhotonFlux(p, irrad); |
708 |
} |
709 |
|
710 |
|
711 |
|
712 |
void volumePhotonDensity (PhotonMap *pmap, RAY *ray, COLOR irrad) |
713 |
/* Photon volume density estimate. Returns irradiance at ray -> rop. */ |
714 |
{ |
715 |
unsigned i; |
716 |
PhotonSQNode *sq; |
717 |
float gecc2, r, ph; |
718 |
COLOR flux; |
719 |
|
720 |
setcolor(irrad, 0, 0, 0); |
721 |
|
722 |
if (!pmap -> maxGather) |
723 |
return; |
724 |
|
725 |
pmap -> squeueEnd = 0; |
726 |
findPhotons(pmap, ray); |
727 |
|
728 |
/* Need at least 2 photons */ |
729 |
if (pmap -> squeueEnd < 2) |
730 |
return; |
731 |
|
732 |
if (pmap -> minGather == pmap -> maxGather) { |
733 |
/* No bias compensation. Just do a plain vanilla estimate */ |
734 |
gecc2 = ray -> gecc * ray -> gecc; |
735 |
sq = pmap -> squeue + 1; |
736 |
|
737 |
/* Average radius between furthest two photons to improve accuracy */ |
738 |
r = max(sq -> dist, (sq + 1) -> dist); |
739 |
r = 0.25 * (pmap -> maxDist + r + 2 * sqrt(pmap -> maxDist * r)); |
740 |
|
741 |
/* Skip the extra photon */ |
742 |
for (i = 1 ; i < pmap -> squeueEnd; i++, sq++) { |
743 |
/* Compute phase function for inscattering from photon */ |
744 |
if (gecc2 <= FTINY) |
745 |
ph = 1; |
746 |
else { |
747 |
ph = DOT(ray -> rdir, sq -> photon -> norm) / 127; |
748 |
ph = 1 + gecc2 - 2 * ray -> gecc * ph; |
749 |
ph = (1 - gecc2) / (ph * sqrt(ph)); |
750 |
} |
751 |
|
752 |
getPhotonFlux(sq -> photon, flux); |
753 |
scalecolor(flux, ph); |
754 |
addcolor(irrad, flux); |
755 |
} |
756 |
|
757 |
/* Divide by search volume 4 / 3 * PI * r^3 and phase function |
758 |
normalization factor 1 / (4 * PI) */ |
759 |
scalecolor(irrad, 3 / (16 * PI * PI * r * sqrt(r))); |
760 |
|
761 |
return; |
762 |
} |
763 |
|
764 |
else |
765 |
/* Apply bias compensation to density estimate */ |
766 |
volumeBiasComp(pmap, ray, irrad); |
767 |
} |