ViewVC Help
View File | Revision Log | Show Annotations | Download File | Root Listing
root/radiance/ray/src/rt/pmapcontrib.c
Revision: 2.10
Committed: Tue Sep 1 16:27:52 2015 UTC (8 years, 8 months ago) by greg
Content type: text/plain
Branch: MAIN
CVS Tags: rad5R0
Changes since 2.9: +1 -2 lines
Log Message:
Removed redundant $Id: in file

File Contents

# User Rev Content
1 greg 2.9 #ifndef lint
2 greg 2.10 static const char RCSid[] = "$Id: pmapcontrib.c,v 2.9 2015/08/18 18:45:55 greg Exp $";
3 greg 2.9 #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     */
14    
15    
16     #include "pmapcontrib.h"
17     #include "pmap.h"
18     #include "pmapmat.h"
19     #include "pmapsrc.h"
20     #include "pmaprand.h"
21     #include "pmapio.h"
22     #include "pmapdiag.h"
23     #include "rcontrib.h"
24     #include "otypes.h"
25    
26    
27    
28     static void setPmapContribParams (PhotonMap *pmap, LUTAB *srcContrib)
29     /* Set parameters for light source contributions */
30     {
31     /* Set light source modifier list and appropriate callback to extract
32     * their contributions from the photon map */
33     if (pmap) {
34     pmap -> srcContrib = srcContrib;
35     pmap -> lookup = photonContrib;
36     /* Ensure we get all requested photon contribs during lookups */
37     pmap -> gatherTolerance = 1.0;
38     }
39     }
40    
41    
42    
43     static void checkPmapContribs (const PhotonMap *pmap, LUTAB *srcContrib)
44     /* Check modifiers for light source contributions */
45     {
46     const PhotonPrimary *primary = pmap -> primary;
47     OBJREC *srcMod;
48     unsigned long i, found = 0;
49    
50     /* Make sure at least one of the modifiers is actually in the pmap,
51     * otherwise findPhotons() winds up in an infinite loop! */
52     for (i = pmap -> primarySize; i; --i, ++primary) {
53     if (primary -> srcIdx < 0 || primary -> srcIdx >= nsources)
54     error(INTERNAL, "invalid light source index in photon map");
55    
56 greg 2.8 srcMod = findmaterial(source [primary -> srcIdx].so);
57 greg 2.1 if ((MODCONT*)lu_find(srcContrib, srcMod -> oname) -> data)
58     ++found;
59     }
60    
61     if (!found)
62     error(USER, "modifiers not in photon map");
63     }
64    
65    
66    
67     void initPmapContrib (LUTAB *srcContrib, unsigned numSrcContrib)
68     {
69     unsigned t;
70    
71     for (t = 0; t < NUM_PMAP_TYPES; t++)
72     if (photonMaps [t] && t != PMAP_TYPE_CONTRIB) {
73     sprintf(errmsg, "%s photon map does not support contributions",
74     pmapName [t]);
75     error(USER, errmsg);
76     }
77    
78     /* Get params */
79     setPmapContribParams(contribPmap, srcContrib);
80    
81     if (contribPhotonMapping) {
82     if (contribPmap -> maxGather < numSrcContrib) {
83     /* Adjust density estimate bandwidth if lower than modifier
84     * count, otherwise contributions are missing */
85     error(WARNING, "contrib density estimate bandwidth too low, "
86     "adjusting to modifier count");
87     contribPmap -> maxGather = numSrcContrib;
88     }
89    
90     /* Sanity check */
91     checkPmapContribs(contribPmap, srcContrib);
92     }
93     }
94    
95    
96    
97     void photonContrib (PhotonMap *pmap, RAY *ray, COLOR irrad)
98     /* Sum up light source contributions from photons in pmap->srcContrib */
99     {
100     unsigned i;
101     PhotonSQNode *sq;
102     float r, invArea;
103     RREAL rayCoeff [3];
104 greg 2.5
105 greg 2.1 setcolor(irrad, 0, 0, 0);
106    
107     if (!pmap -> maxGather)
108     return;
109    
110     /* Ignore sources */
111     if (ray -> ro)
112     if (islight(objptr(ray -> ro -> omod) -> otype))
113     return;
114    
115 greg 2.5 /* Get cumulative path
116 greg 2.1 * coefficient up to photon lookup point */
117     raycontrib(rayCoeff, ray, PRIMARY);
118    
119     /* Lookup photons */
120     pmap -> squeueEnd = 0;
121     findPhotons(pmap, ray);
122    
123     /* Need at least 2 photons */
124     if (pmap -> squeueEnd < 2) {
125     #ifdef PMAP_NONEFOUND
126     sprintf(errmsg, "no photons found on %s at (%.3f, %.3f, %.3f)",
127     ray -> ro ? ray -> ro -> oname : "<null>",
128     ray -> rop [0], ray -> rop [1], ray -> rop [2]);
129     error(WARNING, errmsg);
130     #endif
131    
132     return;
133     }
134    
135     /* Average (squared) radius between furthest two photons to improve
136     * accuracy and get inverse search area 1 / (PI * r^2), with extra
137     * normalisation factor 1 / PI for ambient calculation */
138     sq = pmap -> squeue + 1;
139     r = max(sq -> dist, (sq + 1) -> dist);
140     r = 0.25 * (pmap -> maxDist + r + 2 * sqrt(pmap -> maxDist * r));
141     invArea = 1 / (PI * PI * r);
142    
143     /* Skip the extra photon */
144     for (i = 1 ; i < pmap -> squeueEnd; i++, sq++) {
145     COLOR flux;
146    
147     /* Get photon's contribution to density estimate */
148     getPhotonFlux(sq -> photon, flux);
149     scalecolor(flux, invArea);
150     #ifdef PMAP_EPANECHNIKOV
151     /* Apply Epanechnikov kernel to photon flux (dists are squared) */
152     scalecolor(flux, 2 * (1 - sq -> dist / r));
153     #endif
154     addcolor(irrad, flux);
155    
156     if (pmap -> srcContrib) {
157     const PhotonPrimary *primary = pmap -> primary +
158     sq -> photon -> primary;
159 greg 2.7 const SRCREC *sp = &source[primary -> srcIdx];
160 greg 2.8 OBJREC *srcMod = findmaterial(sp -> so);
161 greg 2.1 MODCONT *srcContrib = (MODCONT*)lu_find(pmap -> srcContrib,
162     srcMod -> oname) -> data;
163 greg 2.6 if (!srcContrib)
164     continue;
165    
166     /* Photon's emitting light source has modifier whose
167     * contributions are sought */
168     double srcBinReal;
169     int srcBin;
170     RAY srcRay;
171    
172     if (srcContrib -> binv -> type != NUM) {
173     /* Use intersection function to set shadow ray parameters
174     * if it's not simply a constant
175     */
176     rayorigin(&srcRay, SHADOW, NULL, NULL);
177     srcRay.rsrc = primary -> srcIdx;
178     VCOPY(srcRay.rorg, primary -> pos);
179 greg 2.7 decodedir(srcRay.rdir, primary -> dir);
180    
181     if (!(sp->sflags & SDISTANT ? sourcehit(&srcRay)
182     : (*ofun[sp -> so -> otype].funp)(sp -> so, &srcRay)))
183 greg 2.6 continue; /* XXX shouldn't happen! */
184 greg 2.7
185 greg 2.6 worldfunc(RCCONTEXT, &srcRay);
186     set_eparams((char *)srcContrib -> params);
187     }
188    
189     if ((srcBinReal = evalue(srcContrib -> binv)) < -.5)
190     continue; /* silently ignore negative bins */
191 greg 2.5
192 greg 2.6 if ((srcBin = srcBinReal + .5) >= srcContrib -> nbins) {
193     error(WARNING, "bad bin number (ignored)");
194     continue;
195     }
196 greg 2.1
197 greg 2.6 if (!contrib) {
198     /* Ray coefficient mode; normalise by light source radiance
199     * after applying distrib pattern */
200     int j;
201     raytexture(ray, srcMod -> omod);
202     setcolor(ray -> rcol, srcMod -> oargs.farg [0],
203 greg 2.1 srcMod -> oargs.farg [1], srcMod -> oargs.farg [2]);
204 greg 2.6 multcolor(ray -> rcol, ray -> pcol);
205     for (j = 0; j < 3; j++)
206     flux [j] = ray -> rcol [j] ? flux [j] / ray -> rcol [j]
207 greg 2.1 : 0;
208 greg 2.6 }
209 greg 2.1
210 greg 2.6 multcolor(flux, rayCoeff);
211     addcolor(srcContrib -> cbin [srcBin], flux);
212 greg 2.1 }
213     }
214 greg 2.5
215 greg 2.1 return;
216     }
217    
218    
219    
220     void distribPhotonContrib (PhotonMap* pm)
221     {
222     EmissionMap emap;
223     char errmsg2 [128];
224     unsigned srcIdx;
225     double *srcFlux; /* Emitted flux per light source */
226     const double srcDistribTarget = /* Target photon count per source */
227     nsources ? (double)pm -> distribTarget / nsources : 0;
228    
229     if (!pm)
230     error(USER, "no photon map defined");
231    
232     if (!nsources)
233     error(USER, "no light sources");
234    
235     /* Allocate photon flux per light source; this differs for every
236     * source as all sources contribute the same number of distributed
237     * photons (srcDistribTarget), hence the number of photons emitted per
238     * source does not correlate with its emitted flux. The resulting flux
239     * per photon is therefore adjusted individually for each source. */
240     if (!(srcFlux = calloc(nsources, sizeof(double))))
241     error(SYSTEM, "cannot allocate source flux");
242    
243     /* ================================================================
244     * INITIALISASHUNN - Set up emisshunn and scattering funcs
245     * ================================================================ */
246     emap.samples = NULL;
247     emap.src = NULL;
248     emap.maxPartitions = MAXSPART;
249     emap.partitions = (unsigned char*)malloc(emap.maxPartitions >> 1);
250     if (!emap.partitions)
251     error(USER, "can't allocate source partitions");
252    
253     initPhotonMap(pm, PMAP_TYPE_CONTRIB);
254     initPhotonEmissionFuncs();
255     initPhotonScatterFuncs();
256    
257     /* Get photon ports if specified */
258     if (ambincl == 1)
259     getPhotonPorts();
260    
261     /* Get photon sensor modifiers */
262     getPhotonSensors(photonSensorList);
263    
264     /* Seed RNGs for photon distribution */
265     pmapSeed(randSeed, partState);
266     pmapSeed(randSeed, emitState);
267     pmapSeed(randSeed, cntState);
268     pmapSeed(randSeed, mediumState);
269     pmapSeed(randSeed, scatterState);
270     pmapSeed(randSeed, rouletteState);
271    
272     /* Record start time and enable progress report signal handler */
273     repStartTime = time(NULL);
274 rschregle 2.3 #ifdef SIGCONT
275     signal(SIGCONT, pmapDistribReport);
276     #endif
277 greg 2.1
278     for (srcIdx = 0; srcIdx < nsources; srcIdx++) {
279     unsigned portCnt = 0, passCnt = 0, prePassCnt = 0;
280     double srcNumEmit = 0; /* # photons to emit from source */
281     unsigned long srcNumDistrib = pm -> heapEnd; /* # photons stored */
282    
283     srcFlux [srcIdx] = repProgress = 0;
284     emap.src = source + srcIdx;
285    
286     if (photonRepTime)
287     eputs("\n");
288    
289     /* =============================================================
290     * FLUX INTEGRATION - Get total flux emitted from light source
291     * ============================================================= */
292     do {
293     emap.port = emap.src -> sflags & SDISTANT
294     ? photonPorts + portCnt : NULL;
295     photonPartition [emap.src -> so -> otype] (&emap);
296    
297     if (photonRepTime) {
298     sprintf(errmsg, "Integrating flux from source %s (mod %s) ",
299     source [srcIdx].so -> oname,
300     objptr(source [srcIdx].so -> omod) -> oname);
301    
302     if (emap.port) {
303     sprintf(errmsg2, "via port %s ",
304     photonPorts [portCnt].so -> oname);
305     strcat(errmsg, errmsg2);
306     }
307    
308     sprintf(errmsg2, "(%lu partitions)...\n",
309     emap.numPartitions);
310     strcat(errmsg, errmsg2);
311     eputs(errmsg);
312     fflush(stderr);
313     }
314    
315     for (emap.partitionCnt = 0;
316     emap.partitionCnt < emap.numPartitions;
317     emap.partitionCnt++) {
318     initPhotonEmission(&emap, pdfSamples);
319     srcFlux [srcIdx] += colorAvg(emap.partFlux);
320     }
321    
322     portCnt++;
323     } while (portCnt < numPhotonPorts);
324    
325     if (srcFlux [srcIdx] < FTINY) {
326     sprintf(errmsg, "source %s has zero emission",
327     source [srcIdx].so -> oname);
328     error(WARNING, errmsg);
329     }
330     else {
331     /* ==========================================================
332     * 2-PASS PHOTON DISTRIBUTION
333     * Pass 1 (pre): emit fraction of target photon count
334     * Pass 2 (main): based on outcome of pass 1, estimate
335     * remaining number of photons to emit to
336     * approximate target count
337     * ========================================================== */
338     do {
339     if (!passCnt) {
340     /* INIT PASS 1 */
341     if (++prePassCnt > maxPreDistrib) {
342     /* Warn if no photons contributed after sufficient
343     * iterations */
344     sprintf(errmsg, "too many prepasses, no photons "
345     "from source %s", source [srcIdx].so -> oname);
346     error(WARNING, errmsg);
347     break;
348     }
349    
350     /* Num to emit is fraction of target count */
351     srcNumEmit = preDistrib * srcDistribTarget;
352     }
353    
354     else {
355     /* INIT PASS 2 */
356     /* Based on the outcome of the predistribution we can now
357     * figure out how many more photons we have to emit from
358     * the current source to meet the target count,
359     * srcDistribTarget. This value is clamped to 0 in case
360     * the target has already been exceeded in pass 1.
361     * srcNumEmit and srcNumDistrib is the number of photons
362     * emitted and distributed (stored) from the current
363     * source in pass 1, respectively. */
364     srcNumDistrib = pm -> heapEnd - srcNumDistrib;
365     srcNumEmit *= srcNumDistrib
366     ? max(srcDistribTarget/srcNumDistrib, 1) - 1
367     : 0;
368    
369     if (!srcNumEmit)
370     /* No photons left to distribute in main pass */
371     break;
372     }
373    
374     /* Set completion count for progress report */
375     repComplete = srcNumEmit + repProgress;
376     portCnt = 0;
377    
378     do {
379     emap.port = emap.src -> sflags & SDISTANT
380     ? photonPorts + portCnt : NULL;
381     photonPartition [emap.src -> so -> otype] (&emap);
382    
383     if (photonRepTime) {
384     if (!passCnt)
385     sprintf(errmsg, "PREPASS %d on source %s (mod %s) ",
386     prePassCnt, source [srcIdx].so -> oname,
387     objptr(source[srcIdx].so->omod) -> oname);
388     else
389     sprintf(errmsg, "MAIN PASS on source %s (mod %s) ",
390     source [srcIdx].so -> oname,
391     objptr(source[srcIdx].so->omod) -> oname);
392    
393     if (emap.port) {
394     sprintf(errmsg2, "via port %s ",
395     photonPorts [portCnt].so -> oname);
396     strcat(errmsg, errmsg2);
397     }
398    
399     sprintf(errmsg2, "(%lu partitions)...\n",
400     emap.numPartitions);
401     strcat(errmsg, errmsg2);
402     eputs(errmsg);
403     fflush(stderr);
404     }
405    
406     for (emap.partitionCnt = 0;
407     emap.partitionCnt < emap.numPartitions;
408     emap.partitionCnt++) {
409     double partNumEmit;
410     unsigned long partEmitCnt;
411    
412     /* Get photon origin within current source partishunn
413     * and build emission map */
414     photonOrigin [emap.src -> so -> otype] (&emap);
415     initPhotonEmission(&emap, pdfSamples);
416    
417     /* Number of photons to emit from ziss partishunn;
418     * scale according to its normalised contribushunn to
419     * the emitted source flux */
420     partNumEmit = srcNumEmit * colorAvg(emap.partFlux) /
421     srcFlux [srcIdx];
422     partEmitCnt = (unsigned long)partNumEmit;
423    
424     /* Probabilistically account for fractional photons */
425     if (pmapRandom(cntState) < partNumEmit - partEmitCnt)
426     partEmitCnt++;
427    
428     /* Integer counter avoids FP rounding errors */
429     while (partEmitCnt--) {
430     RAY photonRay;
431    
432     /* Emit photon according to PDF (if any), allocate
433     * associated primary ray, and trace through scene
434     * until absorbed/leaked */
435     emitPhoton(&emap, &photonRay);
436     addPhotonPrimary(pm, &photonRay);
437     tracePhoton(&photonRay);
438    
439     /* Record progress */
440     repProgress++;
441    
442     if (photonRepTime > 0 &&
443     time(NULL) >= repLastTime + photonRepTime)
444     pmapDistribReport();
445 rschregle 2.3 #ifdef SIGCONT
446 greg 2.1 else signal(SIGCONT, pmapDistribReport);
447     #endif
448     }
449     }
450    
451     portCnt++;
452     } while (portCnt < numPhotonPorts);
453    
454     if (pm -> heapEnd == srcNumDistrib)
455     /* Double preDistrib in case no photons were stored
456     * for this source and redo pass 1 */
457     preDistrib *= 2;
458     else {
459     /* Now do pass 2 */
460     passCnt++;
461     if (photonRepTime)
462     eputs("\n");
463     }
464     } while (passCnt < 2);
465    
466     /* Flux per photon emitted from this source; repProgress is the
467     * number of emitted photons after both passes */
468     srcFlux [srcIdx] = repProgress ? srcFlux [srcIdx] / repProgress
469     : 0;
470     }
471     }
472    
473     /* ================================================================
474     * POST-DISTRIBUTION - Set photon flux and build kd-tree, etc.
475     * ================================================================ */
476 rschregle 2.3 #ifdef SIGCONT
477     signal(SIGCONT, SIG_DFL);
478     #endif
479 greg 2.1 free(emap.samples);
480    
481     if (!pm -> heapEnd)
482     error(USER, "empty photon map");
483    
484     /* Check for valid primary photon rays */
485     if (!pm -> primary)
486     error(INTERNAL, "no primary rays in contribution photon map");
487    
488     if (pm -> primary [pm -> primaryEnd].srcIdx < 0)
489     /* Last primary ray is unused, so decrement counter */
490     pm -> primaryEnd--;
491    
492     if (photonRepTime) {
493     eputs("\nBuilding contrib photon heap...\n");
494     fflush(stderr);
495     }
496    
497     balancePhotons(pm, srcFlux);
498     }