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root/radiance/ray/src/rt/pmapcontrib.c
Revision: 2.5
Committed: Wed May 20 12:58:31 2015 UTC (9 years, 11 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.4: +26 -27 lines
Log Message:
Added appropriate setting of ray parameters for bin rcontrib evaluation

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 2.5 $Id: pmapcontrib.c,v 2.4 2015/05/08 13:20:23 rschregle 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    
162     if (srcContrib) {
163     /* Photon's emitting light source has modifier whose
164     * contributions are sought */
165 greg 2.5 double srcBinReal;
166 greg 2.1 int srcBin;
167 greg 2.5 RAY srcRay;
168 greg 2.1
169 greg 2.5 if (srcContrib -> binv -> type != NUM) {
170     /* Use intersection function to set shadow ray parameters
171     */
172     rayorigin(&srcRay, SHADOW, NULL, NULL);
173     srcRay.rsrc = primary -> srcIdx;
174     VCOPY(srcRay.rorg, primary -> pos);
175     VCOPY(srcRay.rdir, primary -> dir);
176     if (!(source [primary -> srcIdx].sflags & SDISTANT ?
177     sourcehit(&srcRay) :
178     (*ofun[sp -> so -> otype].funp)(sp -> so, &srcRay)))
179     continue; /* XXX shouldn't happen! */
180     worldfunc(RCCONTEXT, &srcRay);
181     set_eparams((char *)srcContrib -> params);
182     }
183     if ((srcBinReal = evalue(srcContrib -> binv)) < -.5)
184     continue; /* silently ignore negative bins */
185    
186     if ((srcBin = srcBinReal + .5) >= srcContrib -> nbins) {
187 greg 2.1 error(WARNING, "bad bin number (ignored)");
188     continue;
189     }
190    
191     if (!contrib) {
192     /* Ray coefficient mode; normalise by light source radiance
193     * after applying distrib pattern */
194     int j;
195     raytexture(ray, srcMod -> omod);
196     setcolor(ray -> rcol, srcMod -> oargs.farg [0],
197     srcMod -> oargs.farg [1], srcMod -> oargs.farg [2]);
198     multcolor(ray -> rcol, ray -> pcol);
199     for (j = 0; j < 3; j++)
200     flux [j] = ray -> rcol [j] ? flux [j] / ray -> rcol [j]
201     : 0;
202     }
203    
204     multcolor(flux, rayCoeff);
205     addcolor(srcContrib -> cbin [srcBin], flux);
206     }
207     else fprintf(stderr, "Skipped contrib from %s\n", srcMod -> oname);
208     }
209     }
210 greg 2.5
211 greg 2.1 return;
212     }
213    
214    
215    
216     void distribPhotonContrib (PhotonMap* pm)
217     {
218     EmissionMap emap;
219     char errmsg2 [128];
220     unsigned srcIdx;
221     double *srcFlux; /* Emitted flux per light source */
222     const double srcDistribTarget = /* Target photon count per source */
223     nsources ? (double)pm -> distribTarget / nsources : 0;
224    
225     if (!pm)
226     error(USER, "no photon map defined");
227    
228     if (!nsources)
229     error(USER, "no light sources");
230    
231     /* Allocate photon flux per light source; this differs for every
232     * source as all sources contribute the same number of distributed
233     * photons (srcDistribTarget), hence the number of photons emitted per
234     * source does not correlate with its emitted flux. The resulting flux
235     * per photon is therefore adjusted individually for each source. */
236     if (!(srcFlux = calloc(nsources, sizeof(double))))
237     error(SYSTEM, "cannot allocate source flux");
238    
239     /* ================================================================
240     * INITIALISASHUNN - Set up emisshunn and scattering funcs
241     * ================================================================ */
242     emap.samples = NULL;
243     emap.src = NULL;
244     emap.maxPartitions = MAXSPART;
245     emap.partitions = (unsigned char*)malloc(emap.maxPartitions >> 1);
246     if (!emap.partitions)
247     error(USER, "can't allocate source partitions");
248    
249     initPhotonMap(pm, PMAP_TYPE_CONTRIB);
250     initPhotonEmissionFuncs();
251     initPhotonScatterFuncs();
252    
253     /* Get photon ports if specified */
254     if (ambincl == 1)
255     getPhotonPorts();
256    
257     /* Get photon sensor modifiers */
258     getPhotonSensors(photonSensorList);
259    
260     /* Seed RNGs for photon distribution */
261     pmapSeed(randSeed, partState);
262     pmapSeed(randSeed, emitState);
263     pmapSeed(randSeed, cntState);
264     pmapSeed(randSeed, mediumState);
265     pmapSeed(randSeed, scatterState);
266     pmapSeed(randSeed, rouletteState);
267    
268     /* Record start time and enable progress report signal handler */
269     repStartTime = time(NULL);
270 rschregle 2.3 #ifdef SIGCONT
271     signal(SIGCONT, pmapDistribReport);
272     #endif
273 greg 2.1
274     for (srcIdx = 0; srcIdx < nsources; srcIdx++) {
275     unsigned portCnt = 0, passCnt = 0, prePassCnt = 0;
276     double srcNumEmit = 0; /* # photons to emit from source */
277     unsigned long srcNumDistrib = pm -> heapEnd; /* # photons stored */
278    
279     srcFlux [srcIdx] = repProgress = 0;
280     emap.src = source + srcIdx;
281    
282     if (photonRepTime)
283     eputs("\n");
284    
285     /* =============================================================
286     * FLUX INTEGRATION - Get total flux emitted from light source
287     * ============================================================= */
288     do {
289     emap.port = emap.src -> sflags & SDISTANT
290     ? photonPorts + portCnt : NULL;
291     photonPartition [emap.src -> so -> otype] (&emap);
292    
293     if (photonRepTime) {
294     sprintf(errmsg, "Integrating flux from source %s (mod %s) ",
295     source [srcIdx].so -> oname,
296     objptr(source [srcIdx].so -> omod) -> oname);
297    
298     if (emap.port) {
299     sprintf(errmsg2, "via port %s ",
300     photonPorts [portCnt].so -> oname);
301     strcat(errmsg, errmsg2);
302     }
303    
304     sprintf(errmsg2, "(%lu partitions)...\n",
305     emap.numPartitions);
306     strcat(errmsg, errmsg2);
307     eputs(errmsg);
308     fflush(stderr);
309     }
310    
311     for (emap.partitionCnt = 0;
312     emap.partitionCnt < emap.numPartitions;
313     emap.partitionCnt++) {
314     initPhotonEmission(&emap, pdfSamples);
315     srcFlux [srcIdx] += colorAvg(emap.partFlux);
316     }
317    
318     portCnt++;
319     } while (portCnt < numPhotonPorts);
320    
321     if (srcFlux [srcIdx] < FTINY) {
322     sprintf(errmsg, "source %s has zero emission",
323     source [srcIdx].so -> oname);
324     error(WARNING, errmsg);
325     }
326     else {
327     /* ==========================================================
328     * 2-PASS PHOTON DISTRIBUTION
329     * Pass 1 (pre): emit fraction of target photon count
330     * Pass 2 (main): based on outcome of pass 1, estimate
331     * remaining number of photons to emit to
332     * approximate target count
333     * ========================================================== */
334     do {
335     if (!passCnt) {
336     /* INIT PASS 1 */
337     if (++prePassCnt > maxPreDistrib) {
338     /* Warn if no photons contributed after sufficient
339     * iterations */
340     sprintf(errmsg, "too many prepasses, no photons "
341     "from source %s", source [srcIdx].so -> oname);
342     error(WARNING, errmsg);
343     break;
344     }
345    
346     /* Num to emit is fraction of target count */
347     srcNumEmit = preDistrib * srcDistribTarget;
348     }
349    
350     else {
351     /* INIT PASS 2 */
352     /* Based on the outcome of the predistribution we can now
353     * figure out how many more photons we have to emit from
354     * the current source to meet the target count,
355     * srcDistribTarget. This value is clamped to 0 in case
356     * the target has already been exceeded in pass 1.
357     * srcNumEmit and srcNumDistrib is the number of photons
358     * emitted and distributed (stored) from the current
359     * source in pass 1, respectively. */
360     srcNumDistrib = pm -> heapEnd - srcNumDistrib;
361     srcNumEmit *= srcNumDistrib
362     ? max(srcDistribTarget/srcNumDistrib, 1) - 1
363     : 0;
364    
365     if (!srcNumEmit)
366     /* No photons left to distribute in main pass */
367     break;
368     }
369    
370     /* Set completion count for progress report */
371     repComplete = srcNumEmit + repProgress;
372     portCnt = 0;
373    
374     do {
375     emap.port = emap.src -> sflags & SDISTANT
376     ? photonPorts + portCnt : NULL;
377     photonPartition [emap.src -> so -> otype] (&emap);
378    
379     if (photonRepTime) {
380     if (!passCnt)
381     sprintf(errmsg, "PREPASS %d on source %s (mod %s) ",
382     prePassCnt, source [srcIdx].so -> oname,
383     objptr(source[srcIdx].so->omod) -> oname);
384     else
385     sprintf(errmsg, "MAIN PASS on source %s (mod %s) ",
386     source [srcIdx].so -> oname,
387     objptr(source[srcIdx].so->omod) -> oname);
388    
389     if (emap.port) {
390     sprintf(errmsg2, "via port %s ",
391     photonPorts [portCnt].so -> oname);
392     strcat(errmsg, errmsg2);
393     }
394    
395     sprintf(errmsg2, "(%lu partitions)...\n",
396     emap.numPartitions);
397     strcat(errmsg, errmsg2);
398     eputs(errmsg);
399     fflush(stderr);
400     }
401    
402     for (emap.partitionCnt = 0;
403     emap.partitionCnt < emap.numPartitions;
404     emap.partitionCnt++) {
405     double partNumEmit;
406     unsigned long partEmitCnt;
407    
408     /* Get photon origin within current source partishunn
409     * and build emission map */
410     photonOrigin [emap.src -> so -> otype] (&emap);
411     initPhotonEmission(&emap, pdfSamples);
412    
413     /* Number of photons to emit from ziss partishunn;
414     * scale according to its normalised contribushunn to
415     * the emitted source flux */
416     partNumEmit = srcNumEmit * colorAvg(emap.partFlux) /
417     srcFlux [srcIdx];
418     partEmitCnt = (unsigned long)partNumEmit;
419    
420     /* Probabilistically account for fractional photons */
421     if (pmapRandom(cntState) < partNumEmit - partEmitCnt)
422     partEmitCnt++;
423    
424     /* Integer counter avoids FP rounding errors */
425     while (partEmitCnt--) {
426     RAY photonRay;
427    
428     /* Emit photon according to PDF (if any), allocate
429     * associated primary ray, and trace through scene
430     * until absorbed/leaked */
431     emitPhoton(&emap, &photonRay);
432     addPhotonPrimary(pm, &photonRay);
433     tracePhoton(&photonRay);
434    
435     /* Record progress */
436     repProgress++;
437    
438     if (photonRepTime > 0 &&
439     time(NULL) >= repLastTime + photonRepTime)
440     pmapDistribReport();
441 rschregle 2.3 #ifdef SIGCONT
442 greg 2.1 else signal(SIGCONT, pmapDistribReport);
443     #endif
444     }
445     }
446    
447     portCnt++;
448     } while (portCnt < numPhotonPorts);
449    
450     if (pm -> heapEnd == srcNumDistrib)
451     /* Double preDistrib in case no photons were stored
452     * for this source and redo pass 1 */
453     preDistrib *= 2;
454     else {
455     /* Now do pass 2 */
456     passCnt++;
457     if (photonRepTime)
458     eputs("\n");
459     }
460     } while (passCnt < 2);
461    
462     /* Flux per photon emitted from this source; repProgress is the
463     * number of emitted photons after both passes */
464     srcFlux [srcIdx] = repProgress ? srcFlux [srcIdx] / repProgress
465     : 0;
466     }
467     }
468    
469     /* ================================================================
470     * POST-DISTRIBUTION - Set photon flux and build kd-tree, etc.
471     * ================================================================ */
472 rschregle 2.3 #ifdef SIGCONT
473     signal(SIGCONT, SIG_DFL);
474     #endif
475 greg 2.1 free(emap.samples);
476    
477     if (!pm -> heapEnd)
478     error(USER, "empty photon map");
479    
480     /* Check for valid primary photon rays */
481     if (!pm -> primary)
482     error(INTERNAL, "no primary rays in contribution photon map");
483    
484     if (pm -> primary [pm -> primaryEnd].srcIdx < 0)
485     /* Last primary ray is unused, so decrement counter */
486     pm -> primaryEnd--;
487    
488     if (photonRepTime) {
489     eputs("\nBuilding contrib photon heap...\n");
490     fflush(stderr);
491     }
492    
493     balancePhotons(pm, srcFlux);
494     }