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root/radiance/ray/src/rt/pmapcontrib.c
Revision: 2.6
Committed: Wed May 20 13:43:28 2015 UTC (9 years ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.5: +42 -41 lines
Log Message:
Eliminated debug message

File Contents

# User Rev Content
1 greg 2.1 /*
2     ==================================================================
3     Photon map support for light source contributions
4    
5     Roland Schregle (roland.schregle@{hslu.ch, gmail.com})
6 rschregle 2.4 (c) Lucerne University of Applied Sciences and Arts,
7     supported by the Swiss National Science Foundation (SNSF, #147053)
8 greg 2.1 ==================================================================
9    
10 greg 2.6 $Id: pmapcontrib.c,v 2.5 2015/05/20 12:58:31 greg Exp $
11 greg 2.1 */
12    
13    
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     static void setPmapContribParams (PhotonMap *pmap, LUTAB *srcContrib)
27     /* Set parameters for light source contributions */
28     {
29     /* Set light source modifier list and appropriate callback to extract
30     * their contributions from the photon map */
31     if (pmap) {
32     pmap -> srcContrib = srcContrib;
33     pmap -> lookup = photonContrib;
34     /* Ensure we get all requested photon contribs during lookups */
35     pmap -> gatherTolerance = 1.0;
36     }
37     }
38    
39    
40    
41     static void checkPmapContribs (const PhotonMap *pmap, LUTAB *srcContrib)
42     /* Check modifiers for light source contributions */
43     {
44     const PhotonPrimary *primary = pmap -> primary;
45     OBJREC *srcMod;
46     unsigned long i, found = 0;
47    
48     /* Make sure at least one of the modifiers is actually in the pmap,
49     * otherwise findPhotons() winds up in an infinite loop! */
50     for (i = pmap -> primarySize; i; --i, ++primary) {
51     if (primary -> srcIdx < 0 || primary -> srcIdx >= nsources)
52     error(INTERNAL, "invalid light source index in photon map");
53    
54     srcMod = objptr(source [primary -> srcIdx].so -> omod);
55     if ((MODCONT*)lu_find(srcContrib, srcMod -> oname) -> data)
56     ++found;
57     }
58    
59     if (!found)
60     error(USER, "modifiers not in photon map");
61     }
62    
63    
64    
65     void initPmapContrib (LUTAB *srcContrib, unsigned numSrcContrib)
66     {
67     unsigned t;
68    
69     for (t = 0; t < NUM_PMAP_TYPES; t++)
70     if (photonMaps [t] && t != PMAP_TYPE_CONTRIB) {
71     sprintf(errmsg, "%s photon map does not support contributions",
72     pmapName [t]);
73     error(USER, errmsg);
74     }
75    
76     /* Get params */
77     setPmapContribParams(contribPmap, srcContrib);
78    
79     if (contribPhotonMapping) {
80     if (contribPmap -> maxGather < numSrcContrib) {
81     /* Adjust density estimate bandwidth if lower than modifier
82     * count, otherwise contributions are missing */
83     error(WARNING, "contrib density estimate bandwidth too low, "
84     "adjusting to modifier count");
85     contribPmap -> maxGather = numSrcContrib;
86     }
87    
88     /* Sanity check */
89     checkPmapContribs(contribPmap, srcContrib);
90     }
91     }
92    
93    
94    
95     void photonContrib (PhotonMap *pmap, RAY *ray, COLOR irrad)
96     /* Sum up light source contributions from photons in pmap->srcContrib */
97     {
98     unsigned i;
99     PhotonSQNode *sq;
100     float r, invArea;
101     RREAL rayCoeff [3];
102 greg 2.5
103 greg 2.1 setcolor(irrad, 0, 0, 0);
104    
105     if (!pmap -> maxGather)
106     return;
107    
108     /* Ignore sources */
109     if (ray -> ro)
110     if (islight(objptr(ray -> ro -> omod) -> otype))
111     return;
112    
113 greg 2.5 /* Get cumulative path
114 greg 2.1 * coefficient up to photon lookup point */
115     raycontrib(rayCoeff, ray, PRIMARY);
116    
117     /* Lookup photons */
118     pmap -> squeueEnd = 0;
119     findPhotons(pmap, ray);
120    
121     /* Need at least 2 photons */
122     if (pmap -> squeueEnd < 2) {
123     #ifdef PMAP_NONEFOUND
124     sprintf(errmsg, "no photons found on %s at (%.3f, %.3f, %.3f)",
125     ray -> ro ? ray -> ro -> oname : "<null>",
126     ray -> rop [0], ray -> rop [1], ray -> rop [2]);
127     error(WARNING, errmsg);
128     #endif
129    
130     return;
131     }
132    
133     /* Average (squared) radius between furthest two photons to improve
134     * accuracy and get inverse search area 1 / (PI * r^2), with extra
135     * normalisation factor 1 / PI for ambient calculation */
136     sq = pmap -> squeue + 1;
137     r = max(sq -> dist, (sq + 1) -> dist);
138     r = 0.25 * (pmap -> maxDist + r + 2 * sqrt(pmap -> maxDist * r));
139     invArea = 1 / (PI * PI * r);
140    
141     /* Skip the extra photon */
142     for (i = 1 ; i < pmap -> squeueEnd; i++, sq++) {
143     COLOR flux;
144    
145     /* Get photon's contribution to density estimate */
146     getPhotonFlux(sq -> photon, flux);
147     scalecolor(flux, invArea);
148     #ifdef PMAP_EPANECHNIKOV
149     /* Apply Epanechnikov kernel to photon flux (dists are squared) */
150     scalecolor(flux, 2 * (1 - sq -> dist / r));
151     #endif
152     addcolor(irrad, flux);
153    
154     if (pmap -> srcContrib) {
155     const PhotonPrimary *primary = pmap -> primary +
156     sq -> photon -> primary;
157 greg 2.5 SRCREC *sp = &source[primary -> srcIdx];
158     OBJREC *srcMod = objptr(sp -> so -> omod);
159 greg 2.1 MODCONT *srcContrib = (MODCONT*)lu_find(pmap -> srcContrib,
160     srcMod -> oname) -> data;
161 greg 2.6 if (!srcContrib)
162     continue;
163    
164     /* Photon's emitting light source has modifier whose
165     * contributions are sought */
166     double srcBinReal;
167     int srcBin;
168     RAY srcRay;
169    
170     if (srcContrib -> binv -> type != NUM) {
171     /* Use intersection function to set shadow ray parameters
172     * if it's not simply a constant
173     */
174     rayorigin(&srcRay, SHADOW, NULL, NULL);
175     srcRay.rsrc = primary -> srcIdx;
176     VCOPY(srcRay.rorg, primary -> pos);
177     VCOPY(srcRay.rdir, primary -> dir);
178     if (!(source [primary -> srcIdx].sflags & SDISTANT ?
179 greg 2.5 sourcehit(&srcRay) :
180     (*ofun[sp -> so -> otype].funp)(sp -> so, &srcRay)))
181 greg 2.6 continue; /* XXX shouldn't happen! */
182     worldfunc(RCCONTEXT, &srcRay);
183     set_eparams((char *)srcContrib -> params);
184     }
185    
186     if ((srcBinReal = evalue(srcContrib -> binv)) < -.5)
187     continue; /* silently ignore negative bins */
188 greg 2.5
189 greg 2.6 if ((srcBin = srcBinReal + .5) >= srcContrib -> nbins) {
190     error(WARNING, "bad bin number (ignored)");
191     continue;
192     }
193 greg 2.1
194 greg 2.6 if (!contrib) {
195     /* Ray coefficient mode; normalise by light source radiance
196     * after applying distrib pattern */
197     int j;
198     raytexture(ray, srcMod -> omod);
199     setcolor(ray -> rcol, srcMod -> oargs.farg [0],
200 greg 2.1 srcMod -> oargs.farg [1], srcMod -> oargs.farg [2]);
201 greg 2.6 multcolor(ray -> rcol, ray -> pcol);
202     for (j = 0; j < 3; j++)
203     flux [j] = ray -> rcol [j] ? flux [j] / ray -> rcol [j]
204 greg 2.1 : 0;
205 greg 2.6 }
206 greg 2.1
207 greg 2.6 multcolor(flux, rayCoeff);
208     addcolor(srcContrib -> cbin [srcBin], flux);
209 greg 2.1 }
210     }
211 greg 2.5
212 greg 2.1 return;
213     }
214    
215    
216    
217     void distribPhotonContrib (PhotonMap* pm)
218     {
219     EmissionMap emap;
220     char errmsg2 [128];
221     unsigned srcIdx;
222     double *srcFlux; /* Emitted flux per light source */
223     const double srcDistribTarget = /* Target photon count per source */
224     nsources ? (double)pm -> distribTarget / nsources : 0;
225    
226     if (!pm)
227     error(USER, "no photon map defined");
228    
229     if (!nsources)
230     error(USER, "no light sources");
231    
232     /* 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))))
238     error(SYSTEM, "cannot allocate source flux");
239    
240     /* ================================================================
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    
269     /* Record start time and enable progress report signal handler */
270     repStartTime = time(NULL);
271 rschregle 2.3 #ifdef SIGCONT
272     signal(SIGCONT, pmapDistribReport);
273     #endif
274 greg 2.1
275     for (srcIdx = 0; srcIdx < nsources; srcIdx++) {
276     unsigned portCnt = 0, passCnt = 0, prePassCnt = 0;
277     double srcNumEmit = 0; /* # photons to emit from source */
278     unsigned long srcNumDistrib = pm -> heapEnd; /* # photons stored */
279    
280     srcFlux [srcIdx] = repProgress = 0;
281     emap.src = source + srcIdx;
282    
283     if (photonRepTime)
284     eputs("\n");
285    
286     /* =============================================================
287     * FLUX INTEGRATION - Get total flux emitted from light source
288     * ============================================================= */
289     do {
290     emap.port = emap.src -> sflags & SDISTANT
291     ? photonPorts + portCnt : NULL;
292     photonPartition [emap.src -> so -> otype] (&emap);
293    
294     if (photonRepTime) {
295     sprintf(errmsg, "Integrating flux from source %s (mod %s) ",
296     source [srcIdx].so -> oname,
297     objptr(source [srcIdx].so -> omod) -> oname);
298    
299     if (emap.port) {
300     sprintf(errmsg2, "via port %s ",
301     photonPorts [portCnt].so -> oname);
302     strcat(errmsg, errmsg2);
303     }
304    
305     sprintf(errmsg2, "(%lu partitions)...\n",
306     emap.numPartitions);
307     strcat(errmsg, errmsg2);
308     eputs(errmsg);
309     fflush(stderr);
310     }
311    
312     for (emap.partitionCnt = 0;
313     emap.partitionCnt < emap.numPartitions;
314     emap.partitionCnt++) {
315     initPhotonEmission(&emap, pdfSamples);
316     srcFlux [srcIdx] += colorAvg(emap.partFlux);
317     }
318    
319     portCnt++;
320     } while (portCnt < numPhotonPorts);
321    
322     if (srcFlux [srcIdx] < FTINY) {
323     sprintf(errmsg, "source %s has zero emission",
324     source [srcIdx].so -> oname);
325     error(WARNING, errmsg);
326     }
327     else {
328     /* ==========================================================
329     * 2-PASS PHOTON DISTRIBUTION
330     * Pass 1 (pre): emit fraction of target photon count
331     * Pass 2 (main): based on outcome of pass 1, estimate
332     * remaining number of photons to emit to
333     * approximate target count
334     * ========================================================== */
335     do {
336     if (!passCnt) {
337     /* INIT PASS 1 */
338     if (++prePassCnt > maxPreDistrib) {
339     /* Warn if no photons contributed after sufficient
340     * iterations */
341     sprintf(errmsg, "too many prepasses, no photons "
342     "from source %s", source [srcIdx].so -> oname);
343     error(WARNING, errmsg);
344     break;
345     }
346    
347     /* Num to emit is fraction of target count */
348     srcNumEmit = preDistrib * srcDistribTarget;
349     }
350    
351     else {
352     /* INIT PASS 2 */
353     /* Based on the outcome of the predistribution we can now
354     * figure out how many more photons we have to emit from
355     * the current source to meet the target count,
356     * srcDistribTarget. This value is clamped to 0 in case
357     * the target has already been exceeded in pass 1.
358     * srcNumEmit and srcNumDistrib is the number of photons
359     * emitted and distributed (stored) from the current
360     * source in pass 1, respectively. */
361     srcNumDistrib = pm -> heapEnd - srcNumDistrib;
362     srcNumEmit *= srcNumDistrib
363     ? max(srcDistribTarget/srcNumDistrib, 1) - 1
364     : 0;
365    
366     if (!srcNumEmit)
367     /* No photons left to distribute in main pass */
368     break;
369     }
370    
371     /* Set completion count for progress report */
372     repComplete = srcNumEmit + repProgress;
373     portCnt = 0;
374    
375     do {
376     emap.port = emap.src -> sflags & SDISTANT
377     ? photonPorts + portCnt : NULL;
378     photonPartition [emap.src -> so -> otype] (&emap);
379    
380     if (photonRepTime) {
381     if (!passCnt)
382     sprintf(errmsg, "PREPASS %d on source %s (mod %s) ",
383     prePassCnt, source [srcIdx].so -> oname,
384     objptr(source[srcIdx].so->omod) -> oname);
385     else
386     sprintf(errmsg, "MAIN PASS on source %s (mod %s) ",
387     source [srcIdx].so -> oname,
388     objptr(source[srcIdx].so->omod) -> oname);
389    
390     if (emap.port) {
391     sprintf(errmsg2, "via port %s ",
392     photonPorts [portCnt].so -> oname);
393     strcat(errmsg, errmsg2);
394     }
395    
396     sprintf(errmsg2, "(%lu partitions)...\n",
397     emap.numPartitions);
398     strcat(errmsg, errmsg2);
399     eputs(errmsg);
400     fflush(stderr);
401     }
402    
403     for (emap.partitionCnt = 0;
404     emap.partitionCnt < emap.numPartitions;
405     emap.partitionCnt++) {
406     double partNumEmit;
407     unsigned long partEmitCnt;
408    
409     /* Get photon origin within current source partishunn
410     * and build emission map */
411     photonOrigin [emap.src -> so -> otype] (&emap);
412     initPhotonEmission(&emap, pdfSamples);
413    
414     /* Number of photons to emit from ziss partishunn;
415     * scale according to its normalised contribushunn to
416     * the emitted source flux */
417     partNumEmit = srcNumEmit * colorAvg(emap.partFlux) /
418     srcFlux [srcIdx];
419     partEmitCnt = (unsigned long)partNumEmit;
420    
421     /* Probabilistically account for fractional photons */
422     if (pmapRandom(cntState) < partNumEmit - partEmitCnt)
423     partEmitCnt++;
424    
425     /* Integer counter avoids FP rounding errors */
426     while (partEmitCnt--) {
427     RAY photonRay;
428    
429     /* Emit photon according to PDF (if any), allocate
430     * associated primary ray, and trace through scene
431     * until absorbed/leaked */
432     emitPhoton(&emap, &photonRay);
433     addPhotonPrimary(pm, &photonRay);
434     tracePhoton(&photonRay);
435    
436     /* Record progress */
437     repProgress++;
438    
439     if (photonRepTime > 0 &&
440     time(NULL) >= repLastTime + photonRepTime)
441     pmapDistribReport();
442 rschregle 2.3 #ifdef SIGCONT
443 greg 2.1 else signal(SIGCONT, pmapDistribReport);
444     #endif
445     }
446     }
447    
448     portCnt++;
449     } while (portCnt < numPhotonPorts);
450    
451     if (pm -> heapEnd == srcNumDistrib)
452     /* Double preDistrib in case no photons were stored
453     * for this source and redo pass 1 */
454     preDistrib *= 2;
455     else {
456     /* Now do pass 2 */
457     passCnt++;
458     if (photonRepTime)
459     eputs("\n");
460     }
461     } while (passCnt < 2);
462    
463     /* Flux per photon emitted from this source; repProgress is the
464     * number of emitted photons after both passes */
465     srcFlux [srcIdx] = repProgress ? srcFlux [srcIdx] / repProgress
466     : 0;
467     }
468     }
469    
470     /* ================================================================
471     * POST-DISTRIBUTION - Set photon flux and build kd-tree, etc.
472     * ================================================================ */
473 rschregle 2.3 #ifdef SIGCONT
474     signal(SIGCONT, SIG_DFL);
475     #endif
476 greg 2.1 free(emap.samples);
477    
478     if (!pm -> heapEnd)
479     error(USER, "empty photon map");
480    
481     /* Check for valid primary photon rays */
482     if (!pm -> primary)
483     error(INTERNAL, "no primary rays in contribution photon map");
484    
485     if (pm -> primary [pm -> primaryEnd].srcIdx < 0)
486     /* Last primary ray is unused, so decrement counter */
487     pm -> primaryEnd--;
488    
489     if (photonRepTime) {
490     eputs("\nBuilding contrib photon heap...\n");
491     fflush(stderr);
492     }
493    
494     balancePhotons(pm, srcFlux);
495     }