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root/radiance/ray/src/rt/pmapcontrib.c
Revision: 2.9
Committed: Tue Aug 18 18:45:55 2015 UTC (8 years, 8 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.8: +4 -1 lines
Log Message:
Added missing RCSid forgotten during initial check-in

File Contents

# User Rev Content
1 greg 2.9 #ifndef lint
2     static const char RCSid[] = "$Id$";
3     #endif
4 greg 2.1 /*
5     ==================================================================
6     Photon map support for light source contributions
7    
8     Roland Schregle (roland.schregle@{hslu.ch, gmail.com})
9 rschregle 2.4 (c) Lucerne University of Applied Sciences and Arts,
10     supported by the Swiss National Science Foundation (SNSF, #147053)
11 greg 2.1 ==================================================================
12    
13 greg 2.9 $Id: pmapcontrib.c,v 2.8 2015/05/21 13:54:59 greg Exp $
14 greg 2.1 */
15    
16    
17     #include "pmapcontrib.h"
18     #include "pmap.h"
19     #include "pmapmat.h"
20     #include "pmapsrc.h"
21     #include "pmaprand.h"
22     #include "pmapio.h"
23     #include "pmapdiag.h"
24     #include "rcontrib.h"
25     #include "otypes.h"
26    
27    
28    
29     static void setPmapContribParams (PhotonMap *pmap, LUTAB *srcContrib)
30     /* Set parameters for light source contributions */
31     {
32     /* Set light source modifier list and appropriate callback to extract
33     * their contributions from the photon map */
34     if (pmap) {
35     pmap -> srcContrib = srcContrib;
36     pmap -> lookup = photonContrib;
37     /* Ensure we get all requested photon contribs during lookups */
38     pmap -> gatherTolerance = 1.0;
39     }
40     }
41    
42    
43    
44     static void checkPmapContribs (const PhotonMap *pmap, LUTAB *srcContrib)
45     /* Check modifiers for light source contributions */
46     {
47     const PhotonPrimary *primary = pmap -> primary;
48     OBJREC *srcMod;
49     unsigned long i, found = 0;
50    
51     /* Make sure at least one of the modifiers is actually in the pmap,
52     * otherwise findPhotons() winds up in an infinite loop! */
53     for (i = pmap -> primarySize; i; --i, ++primary) {
54     if (primary -> srcIdx < 0 || primary -> srcIdx >= nsources)
55     error(INTERNAL, "invalid light source index in photon map");
56    
57 greg 2.8 srcMod = findmaterial(source [primary -> srcIdx].so);
58 greg 2.1 if ((MODCONT*)lu_find(srcContrib, srcMod -> oname) -> data)
59     ++found;
60     }
61    
62     if (!found)
63     error(USER, "modifiers not in photon map");
64     }
65    
66    
67    
68     void initPmapContrib (LUTAB *srcContrib, unsigned numSrcContrib)
69     {
70     unsigned t;
71    
72     for (t = 0; t < NUM_PMAP_TYPES; t++)
73     if (photonMaps [t] && t != PMAP_TYPE_CONTRIB) {
74     sprintf(errmsg, "%s photon map does not support contributions",
75     pmapName [t]);
76     error(USER, errmsg);
77     }
78    
79     /* Get params */
80     setPmapContribParams(contribPmap, srcContrib);
81    
82     if (contribPhotonMapping) {
83     if (contribPmap -> maxGather < numSrcContrib) {
84     /* Adjust density estimate bandwidth if lower than modifier
85     * count, otherwise contributions are missing */
86     error(WARNING, "contrib density estimate bandwidth too low, "
87     "adjusting to modifier count");
88     contribPmap -> maxGather = numSrcContrib;
89     }
90    
91     /* Sanity check */
92     checkPmapContribs(contribPmap, srcContrib);
93     }
94     }
95    
96    
97    
98     void photonContrib (PhotonMap *pmap, RAY *ray, COLOR irrad)
99     /* Sum up light source contributions from photons in pmap->srcContrib */
100     {
101     unsigned i;
102     PhotonSQNode *sq;
103     float r, invArea;
104     RREAL rayCoeff [3];
105 greg 2.5
106 greg 2.1 setcolor(irrad, 0, 0, 0);
107    
108     if (!pmap -> maxGather)
109     return;
110    
111     /* Ignore sources */
112     if (ray -> ro)
113     if (islight(objptr(ray -> ro -> omod) -> otype))
114     return;
115    
116 greg 2.5 /* Get cumulative path
117 greg 2.1 * coefficient up to photon lookup point */
118     raycontrib(rayCoeff, ray, PRIMARY);
119    
120     /* Lookup photons */
121     pmap -> squeueEnd = 0;
122     findPhotons(pmap, ray);
123    
124     /* Need at least 2 photons */
125     if (pmap -> squeueEnd < 2) {
126     #ifdef PMAP_NONEFOUND
127     sprintf(errmsg, "no photons found on %s at (%.3f, %.3f, %.3f)",
128     ray -> ro ? ray -> ro -> oname : "<null>",
129     ray -> rop [0], ray -> rop [1], ray -> rop [2]);
130     error(WARNING, errmsg);
131     #endif
132    
133     return;
134     }
135    
136     /* Average (squared) radius between furthest two photons to improve
137     * accuracy and get inverse search area 1 / (PI * r^2), with extra
138     * normalisation factor 1 / PI for ambient calculation */
139     sq = pmap -> squeue + 1;
140     r = max(sq -> dist, (sq + 1) -> dist);
141     r = 0.25 * (pmap -> maxDist + r + 2 * sqrt(pmap -> maxDist * r));
142     invArea = 1 / (PI * PI * r);
143    
144     /* Skip the extra photon */
145     for (i = 1 ; i < pmap -> squeueEnd; i++, sq++) {
146     COLOR flux;
147    
148     /* Get photon's contribution to density estimate */
149     getPhotonFlux(sq -> photon, flux);
150     scalecolor(flux, invArea);
151     #ifdef PMAP_EPANECHNIKOV
152     /* Apply Epanechnikov kernel to photon flux (dists are squared) */
153     scalecolor(flux, 2 * (1 - sq -> dist / r));
154     #endif
155     addcolor(irrad, flux);
156    
157     if (pmap -> srcContrib) {
158     const PhotonPrimary *primary = pmap -> primary +
159     sq -> photon -> primary;
160 greg 2.7 const SRCREC *sp = &source[primary -> srcIdx];
161 greg 2.8 OBJREC *srcMod = findmaterial(sp -> so);
162 greg 2.1 MODCONT *srcContrib = (MODCONT*)lu_find(pmap -> srcContrib,
163     srcMod -> oname) -> data;
164 greg 2.6 if (!srcContrib)
165     continue;
166    
167     /* Photon's emitting light source has modifier whose
168     * contributions are sought */
169     double srcBinReal;
170     int srcBin;
171     RAY srcRay;
172    
173     if (srcContrib -> binv -> type != NUM) {
174     /* Use intersection function to set shadow ray parameters
175     * if it's not simply a constant
176     */
177     rayorigin(&srcRay, SHADOW, NULL, NULL);
178     srcRay.rsrc = primary -> srcIdx;
179     VCOPY(srcRay.rorg, primary -> pos);
180 greg 2.7 decodedir(srcRay.rdir, primary -> dir);
181    
182     if (!(sp->sflags & SDISTANT ? sourcehit(&srcRay)
183     : (*ofun[sp -> so -> otype].funp)(sp -> so, &srcRay)))
184 greg 2.6 continue; /* XXX shouldn't happen! */
185 greg 2.7
186 greg 2.6 worldfunc(RCCONTEXT, &srcRay);
187     set_eparams((char *)srcContrib -> params);
188     }
189    
190     if ((srcBinReal = evalue(srcContrib -> binv)) < -.5)
191     continue; /* silently ignore negative bins */
192 greg 2.5
193 greg 2.6 if ((srcBin = srcBinReal + .5) >= srcContrib -> nbins) {
194     error(WARNING, "bad bin number (ignored)");
195     continue;
196     }
197 greg 2.1
198 greg 2.6 if (!contrib) {
199     /* Ray coefficient mode; normalise by light source radiance
200     * after applying distrib pattern */
201     int j;
202     raytexture(ray, srcMod -> omod);
203     setcolor(ray -> rcol, srcMod -> oargs.farg [0],
204 greg 2.1 srcMod -> oargs.farg [1], srcMod -> oargs.farg [2]);
205 greg 2.6 multcolor(ray -> rcol, ray -> pcol);
206     for (j = 0; j < 3; j++)
207     flux [j] = ray -> rcol [j] ? flux [j] / ray -> rcol [j]
208 greg 2.1 : 0;
209 greg 2.6 }
210 greg 2.1
211 greg 2.6 multcolor(flux, rayCoeff);
212     addcolor(srcContrib -> cbin [srcBin], flux);
213 greg 2.1 }
214     }
215 greg 2.5
216 greg 2.1 return;
217     }
218    
219    
220    
221     void distribPhotonContrib (PhotonMap* pm)
222     {
223     EmissionMap emap;
224     char errmsg2 [128];
225     unsigned srcIdx;
226     double *srcFlux; /* Emitted flux per light source */
227     const double srcDistribTarget = /* Target photon count per source */
228     nsources ? (double)pm -> distribTarget / nsources : 0;
229    
230     if (!pm)
231     error(USER, "no photon map defined");
232    
233     if (!nsources)
234     error(USER, "no light sources");
235    
236     /* Allocate photon flux per light source; this differs for every
237     * source as all sources contribute the same number of distributed
238     * photons (srcDistribTarget), hence the number of photons emitted per
239     * source does not correlate with its emitted flux. The resulting flux
240     * per photon is therefore adjusted individually for each source. */
241     if (!(srcFlux = calloc(nsources, sizeof(double))))
242     error(SYSTEM, "cannot allocate source flux");
243    
244     /* ================================================================
245     * INITIALISASHUNN - Set up emisshunn and scattering funcs
246     * ================================================================ */
247     emap.samples = NULL;
248     emap.src = NULL;
249     emap.maxPartitions = MAXSPART;
250     emap.partitions = (unsigned char*)malloc(emap.maxPartitions >> 1);
251     if (!emap.partitions)
252     error(USER, "can't allocate source partitions");
253    
254     initPhotonMap(pm, PMAP_TYPE_CONTRIB);
255     initPhotonEmissionFuncs();
256     initPhotonScatterFuncs();
257    
258     /* Get photon ports if specified */
259     if (ambincl == 1)
260     getPhotonPorts();
261    
262     /* Get photon sensor modifiers */
263     getPhotonSensors(photonSensorList);
264    
265     /* Seed RNGs for photon distribution */
266     pmapSeed(randSeed, partState);
267     pmapSeed(randSeed, emitState);
268     pmapSeed(randSeed, cntState);
269     pmapSeed(randSeed, mediumState);
270     pmapSeed(randSeed, scatterState);
271     pmapSeed(randSeed, rouletteState);
272    
273     /* Record start time and enable progress report signal handler */
274     repStartTime = time(NULL);
275 rschregle 2.3 #ifdef SIGCONT
276     signal(SIGCONT, pmapDistribReport);
277     #endif
278 greg 2.1
279     for (srcIdx = 0; srcIdx < nsources; srcIdx++) {
280     unsigned portCnt = 0, passCnt = 0, prePassCnt = 0;
281     double srcNumEmit = 0; /* # photons to emit from source */
282     unsigned long srcNumDistrib = pm -> heapEnd; /* # photons stored */
283    
284     srcFlux [srcIdx] = repProgress = 0;
285     emap.src = source + srcIdx;
286    
287     if (photonRepTime)
288     eputs("\n");
289    
290     /* =============================================================
291     * FLUX INTEGRATION - Get total flux emitted from light source
292     * ============================================================= */
293     do {
294     emap.port = emap.src -> sflags & SDISTANT
295     ? photonPorts + portCnt : NULL;
296     photonPartition [emap.src -> so -> otype] (&emap);
297    
298     if (photonRepTime) {
299     sprintf(errmsg, "Integrating flux from source %s (mod %s) ",
300     source [srcIdx].so -> oname,
301     objptr(source [srcIdx].so -> omod) -> oname);
302    
303     if (emap.port) {
304     sprintf(errmsg2, "via port %s ",
305     photonPorts [portCnt].so -> oname);
306     strcat(errmsg, errmsg2);
307     }
308    
309     sprintf(errmsg2, "(%lu partitions)...\n",
310     emap.numPartitions);
311     strcat(errmsg, errmsg2);
312     eputs(errmsg);
313     fflush(stderr);
314     }
315    
316     for (emap.partitionCnt = 0;
317     emap.partitionCnt < emap.numPartitions;
318     emap.partitionCnt++) {
319     initPhotonEmission(&emap, pdfSamples);
320     srcFlux [srcIdx] += colorAvg(emap.partFlux);
321     }
322    
323     portCnt++;
324     } while (portCnt < numPhotonPorts);
325    
326     if (srcFlux [srcIdx] < FTINY) {
327     sprintf(errmsg, "source %s has zero emission",
328     source [srcIdx].so -> oname);
329     error(WARNING, errmsg);
330     }
331     else {
332     /* ==========================================================
333     * 2-PASS PHOTON DISTRIBUTION
334     * Pass 1 (pre): emit fraction of target photon count
335     * Pass 2 (main): based on outcome of pass 1, estimate
336     * remaining number of photons to emit to
337     * approximate target count
338     * ========================================================== */
339     do {
340     if (!passCnt) {
341     /* INIT PASS 1 */
342     if (++prePassCnt > maxPreDistrib) {
343     /* Warn if no photons contributed after sufficient
344     * iterations */
345     sprintf(errmsg, "too many prepasses, no photons "
346     "from source %s", source [srcIdx].so -> oname);
347     error(WARNING, errmsg);
348     break;
349     }
350    
351     /* Num to emit is fraction of target count */
352     srcNumEmit = preDistrib * srcDistribTarget;
353     }
354    
355     else {
356     /* INIT PASS 2 */
357     /* Based on the outcome of the predistribution we can now
358     * figure out how many more photons we have to emit from
359     * the current source to meet the target count,
360     * srcDistribTarget. This value is clamped to 0 in case
361     * the target has already been exceeded in pass 1.
362     * srcNumEmit and srcNumDistrib is the number of photons
363     * emitted and distributed (stored) from the current
364     * source in pass 1, respectively. */
365     srcNumDistrib = pm -> heapEnd - srcNumDistrib;
366     srcNumEmit *= srcNumDistrib
367     ? max(srcDistribTarget/srcNumDistrib, 1) - 1
368     : 0;
369    
370     if (!srcNumEmit)
371     /* No photons left to distribute in main pass */
372     break;
373     }
374    
375     /* Set completion count for progress report */
376     repComplete = srcNumEmit + repProgress;
377     portCnt = 0;
378    
379     do {
380     emap.port = emap.src -> sflags & SDISTANT
381     ? photonPorts + portCnt : NULL;
382     photonPartition [emap.src -> so -> otype] (&emap);
383    
384     if (photonRepTime) {
385     if (!passCnt)
386     sprintf(errmsg, "PREPASS %d on source %s (mod %s) ",
387     prePassCnt, source [srcIdx].so -> oname,
388     objptr(source[srcIdx].so->omod) -> oname);
389     else
390     sprintf(errmsg, "MAIN PASS on source %s (mod %s) ",
391     source [srcIdx].so -> oname,
392     objptr(source[srcIdx].so->omod) -> oname);
393    
394     if (emap.port) {
395     sprintf(errmsg2, "via port %s ",
396     photonPorts [portCnt].so -> oname);
397     strcat(errmsg, errmsg2);
398     }
399    
400     sprintf(errmsg2, "(%lu partitions)...\n",
401     emap.numPartitions);
402     strcat(errmsg, errmsg2);
403     eputs(errmsg);
404     fflush(stderr);
405     }
406    
407     for (emap.partitionCnt = 0;
408     emap.partitionCnt < emap.numPartitions;
409     emap.partitionCnt++) {
410     double partNumEmit;
411     unsigned long partEmitCnt;
412    
413     /* Get photon origin within current source partishunn
414     * and build emission map */
415     photonOrigin [emap.src -> so -> otype] (&emap);
416     initPhotonEmission(&emap, pdfSamples);
417    
418     /* Number of photons to emit from ziss partishunn;
419     * scale according to its normalised contribushunn to
420     * the emitted source flux */
421     partNumEmit = srcNumEmit * colorAvg(emap.partFlux) /
422     srcFlux [srcIdx];
423     partEmitCnt = (unsigned long)partNumEmit;
424    
425     /* Probabilistically account for fractional photons */
426     if (pmapRandom(cntState) < partNumEmit - partEmitCnt)
427     partEmitCnt++;
428    
429     /* Integer counter avoids FP rounding errors */
430     while (partEmitCnt--) {
431     RAY photonRay;
432    
433     /* Emit photon according to PDF (if any), allocate
434     * associated primary ray, and trace through scene
435     * until absorbed/leaked */
436     emitPhoton(&emap, &photonRay);
437     addPhotonPrimary(pm, &photonRay);
438     tracePhoton(&photonRay);
439    
440     /* Record progress */
441     repProgress++;
442    
443     if (photonRepTime > 0 &&
444     time(NULL) >= repLastTime + photonRepTime)
445     pmapDistribReport();
446 rschregle 2.3 #ifdef SIGCONT
447 greg 2.1 else signal(SIGCONT, pmapDistribReport);
448     #endif
449     }
450     }
451    
452     portCnt++;
453     } while (portCnt < numPhotonPorts);
454    
455     if (pm -> heapEnd == srcNumDistrib)
456     /* Double preDistrib in case no photons were stored
457     * for this source and redo pass 1 */
458     preDistrib *= 2;
459     else {
460     /* Now do pass 2 */
461     passCnt++;
462     if (photonRepTime)
463     eputs("\n");
464     }
465     } while (passCnt < 2);
466    
467     /* Flux per photon emitted from this source; repProgress is the
468     * number of emitted photons after both passes */
469     srcFlux [srcIdx] = repProgress ? srcFlux [srcIdx] / repProgress
470     : 0;
471     }
472     }
473    
474     /* ================================================================
475     * POST-DISTRIBUTION - Set photon flux and build kd-tree, etc.
476     * ================================================================ */
477 rschregle 2.3 #ifdef SIGCONT
478     signal(SIGCONT, SIG_DFL);
479     #endif
480 greg 2.1 free(emap.samples);
481    
482     if (!pm -> heapEnd)
483     error(USER, "empty photon map");
484    
485     /* Check for valid primary photon rays */
486     if (!pm -> primary)
487     error(INTERNAL, "no primary rays in contribution photon map");
488    
489     if (pm -> primary [pm -> primaryEnd].srcIdx < 0)
490     /* Last primary ray is unused, so decrement counter */
491     pm -> primaryEnd--;
492    
493     if (photonRepTime) {
494     eputs("\nBuilding contrib photon heap...\n");
495     fflush(stderr);
496     }
497    
498     balancePhotons(pm, srcFlux);
499     }