ViewVC Help
View File | Revision Log | Show Annotations | Download File | Root Listing
root/radiance/ray/src/rt/source.c
Revision: 2.76
Committed: Mon Feb 1 16:19:49 2021 UTC (3 years, 4 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.75: +9 -11 lines
Log Message:
perf: made use of OVOID and findmaterial() more consistent and efficient

File Contents

# User Rev Content
1 greg 1.1 #ifndef lint
2 greg 2.76 static const char RCSid[] = "$Id: source.c,v 2.75 2021/01/04 19:07:15 greg Exp $";
3 greg 1.1 #endif
4     /*
5     * source.c - routines dealing with illumination sources.
6     *
7 greg 2.29 * External symbols declared in source.h
8     */
9    
10 greg 1.1 #include "ray.h"
11     #include "otypes.h"
12 greg 2.70 #include "otspecial.h"
13 schorsch 2.44 #include "rtotypes.h"
14 greg 1.35 #include "source.h"
15 greg 2.19 #include "random.h"
16 greg 2.64 #include "pmapsrc.h"
17 rschregle 2.67 #include "pmapmat.h"
18 greg 2.19
19 greg 2.22 #ifndef MAXSSAMP
20     #define MAXSSAMP 16 /* maximum samples per ray */
21     #endif
22    
23 greg 1.35 /*
24     * Structures used by direct()
25     */
26 greg 1.1
27 greg 1.35 typedef struct {
28 greg 1.45 int sno; /* source number */
29 greg 1.35 FVECT dir; /* source direction */
30     COLOR coef; /* material coefficient */
31     COLOR val; /* contribution */
32     } CONTRIB; /* direct contribution */
33 greg 1.1
34 greg 1.35 typedef struct {
35 greg 1.45 int sndx; /* source index (to CONTRIB array) */
36 greg 1.35 float brt; /* brightness (for comparison) */
37     } CNTPTR; /* contribution pointer */
38 greg 1.1
39 greg 1.25 static CONTRIB *srccnt; /* source contributions in direct() */
40     static CNTPTR *cntord; /* source ordering in direct() */
41 greg 1.45 static int maxcntr = 0; /* size of contribution arrays */
42 greg 1.1
43 schorsch 2.44 static int cntcmp(const void *p1, const void *p2);
44    
45 greg 1.25
46 greg 2.62 void
47 schorsch 2.44 marksources(void) /* find and mark source objects */
48 greg 1.1 {
49 greg 2.3 int foundsource = 0;
50 greg 1.33 int i;
51 greg 2.62 OBJREC *o, *m;
52     int ns;
53 greg 1.35 /* initialize dispatch table */
54     initstypes();
55     /* find direct sources */
56 greg 2.33 for (i = 0; i < nsceneobjs; i++) {
57 greg 1.1
58     o = objptr(i);
59    
60 greg 1.35 if (!issurface(o->otype) || o->omod == OVOID)
61 greg 1.1 continue;
62 greg 2.36 /* find material */
63 greg 2.76 m = findmaterial(o);
64 greg 2.56 if (m == NULL)
65     continue;
66     if (m->otype == MAT_CLIP) {
67     markclip(m); /* special case for antimatter */
68     continue;
69     }
70     if (!islight(m->otype))
71 greg 2.36 continue; /* not source modifier */
72 greg 1.1
73 greg 1.6 if (m->oargs.nfargs != (m->otype == MAT_GLOW ? 4 :
74     m->otype == MAT_SPOT ? 7 : 3))
75 greg 1.1 objerror(m, USER, "bad # arguments");
76    
77 greg 2.72 if (m->oargs.farg[0] <= FTINY && (m->oargs.farg[1] <= FTINY) &
78     (m->oargs.farg[2] <= FTINY))
79 greg 2.16 continue; /* don't bother */
80 greg 2.61 if (m->otype == MAT_GLOW &&
81     o->otype != OBJ_SOURCE &&
82     m->oargs.farg[3] <= FTINY) {
83     foundsource += (ambounce > 0);
84     continue; /* don't track these */
85     }
86 greg 1.35 if (sfun[o->otype].of == NULL ||
87     sfun[o->otype].of->setsrc == NULL)
88     objerror(o, USER, "illegal material");
89    
90 greg 1.36 if ((ns = newsource()) < 0)
91 greg 1.25 goto memerr;
92 greg 1.1
93 greg 1.37 setsource(&source[ns], o);
94 greg 1.1
95 greg 1.6 if (m->otype == MAT_GLOW) {
96 greg 1.36 source[ns].sflags |= SPROX;
97     source[ns].sl.prox = m->oargs.farg[3];
98 greg 2.61 if (source[ns].sflags & SDISTANT) {
99 greg 1.36 source[ns].sflags |= SSKIP;
100 greg 2.61 foundsource += (ambounce > 0);
101     }
102 greg 1.6 } else if (m->otype == MAT_SPOT) {
103 greg 2.72 if (source[ns].sflags & SDISTANT)
104     objerror(o, WARNING,
105     "distant source is a spotlight");
106 greg 1.36 source[ns].sflags |= SSPOT;
107     if ((source[ns].sl.s = makespot(m)) == NULL)
108 greg 1.33 goto memerr;
109 greg 1.38 if (source[ns].sflags & SFLAT &&
110     !checkspot(source[ns].sl.s,source[ns].snorm)) {
111     objerror(o, WARNING,
112     "invalid spotlight direction");
113     source[ns].sflags |= SSKIP;
114     }
115 greg 1.6 }
116 greg 2.61 foundsource += !(source[ns].sflags & SSKIP);
117 greg 1.1 }
118 greg 2.3 if (!foundsource) {
119 greg 1.25 error(WARNING, "no light sources found");
120     return;
121     }
122 greg 2.65 #if SHADCACHE
123 greg 2.66 for (ns = 0; ns < nsources; ns++) /* initialize obstructor cache */
124     initobscache(ns);
125 greg 2.65 #endif
126 greg 2.64 /* PMAP: disable virtual sources */
127     if (!photonMapping)
128     markvirtuals(); /* find and add virtual sources */
129    
130 greg 1.45 /* allocate our contribution arrays */
131 greg 1.48 maxcntr = nsources + MAXSPART; /* start with this many */
132 greg 1.45 srccnt = (CONTRIB *)malloc(maxcntr*sizeof(CONTRIB));
133     cntord = (CNTPTR *)malloc(maxcntr*sizeof(CNTPTR));
134 greg 2.72 if ((srccnt != NULL) & (cntord != NULL))
135     return;
136 greg 1.25 memerr:
137     error(SYSTEM, "out of memory in marksources");
138 greg 1.1 }
139    
140    
141 greg 2.62 void
142 greg 2.72 distantsources(void) /* only mark distant sources */
143     {
144     int i;
145     OBJREC *o, *m;
146     int ns;
147     /* initialize dispatch table */
148     initstypes();
149     /* sources needed for sourcehit() */
150     for (i = 0; i < nsceneobjs; i++) {
151    
152     o = objptr(i);
153    
154     if ((o->otype != OBJ_SOURCE) | (o->omod == OVOID))
155     continue;
156     /* find material */
157 greg 2.76 m = findmaterial(o);
158 greg 2.72 if (m == NULL)
159     continue;
160     if (!islight(m->otype))
161     continue; /* not source modifier */
162    
163     if (m->oargs.nfargs != (m->otype == MAT_GLOW ? 4 :
164     m->otype == MAT_SPOT ? 7 : 3))
165     objerror(m, USER, "bad # arguments");
166    
167     if (m->oargs.farg[0] <= FTINY && (m->oargs.farg[1] <= FTINY) &
168     (m->oargs.farg[2] <= FTINY))
169     continue; /* don't bother */
170     if (sfun[o->otype].of == NULL ||
171     sfun[o->otype].of->setsrc == NULL)
172     objerror(o, USER, "illegal material");
173    
174     if ((ns = newsource()) < 0)
175     error(SYSTEM, "out of memory in distantsources");
176    
177     setsource(&source[ns], o);
178    
179     if (m->otype == MAT_GLOW) {
180     source[ns].sflags |= SPROX|SSKIP;
181     source[ns].sl.prox = m->oargs.farg[3];
182     } else if (m->otype == MAT_SPOT)
183     objerror(o, WARNING, "distant source is a spotlight");
184     }
185     }
186    
187    
188     void
189 schorsch 2.44 freesources(void) /* free all source structures */
190 greg 2.29 {
191     if (nsources > 0) {
192 greg 2.38 #if SHADCACHE
193     while (nsources--)
194     freeobscache(&source[nsources]);
195     #endif
196 greg 2.29 free((void *)source);
197     source = NULL;
198     nsources = 0;
199     }
200 greg 2.60 markclip(NULL);
201 greg 2.29 if (maxcntr <= 0)
202     return;
203     free((void *)srccnt);
204     srccnt = NULL;
205     free((void *)cntord);
206     cntord = NULL;
207     maxcntr = 0;
208     }
209    
210    
211 greg 2.62 int
212 greg 2.38 srcray( /* send a ray to a source, return domega */
213 greg 2.62 RAY *sr, /* returned source ray */
214 schorsch 2.44 RAY *r, /* ray which hit object */
215     SRCINDEX *si /* source sample index */
216 greg 2.38 )
217 greg 1.1 {
218 greg 2.59 double d; /* distance to source */
219 greg 2.62 SRCREC *srcp;
220 greg 1.1
221 greg 2.59 rayorigin(sr, SHADOW, r, NULL); /* ignore limits */
222 greg 1.1
223 greg 2.59 if (r == NULL)
224     sr->rmax = 0.0;
225    
226     while ((d = nextssamp(sr, si)) != 0.0) {
227     sr->rsrc = si->sn; /* remember source */
228     srcp = source + si->sn;
229     if (srcp->sflags & SDISTANT) {
230     if (srcp->sflags & SSPOT && spotout(sr, srcp->sl.s))
231     continue;
232     return(1); /* sample OK */
233     }
234 greg 1.45 /* local source */
235 greg 1.6 /* check proximity */
236 greg 2.59 if (srcp->sflags & SPROX && d > srcp->sl.prox)
237     continue;
238 greg 1.6 /* check angle */
239 greg 2.59 if (srcp->sflags & SSPOT) {
240     if (spotout(sr, srcp->sl.s))
241     continue;
242 greg 1.45 /* adjust solid angle */
243 greg 2.59 si->dom *= d*d;
244     d += srcp->sl.s->flen;
245     si->dom /= d*d;
246     }
247     return(1); /* sample OK */
248     }
249     return(0); /* no more samples */
250 greg 1.1 }
251    
252    
253 greg 2.62 void
254 greg 2.38 srcvalue( /* punch ray to source and compute value */
255 greg 2.62 RAY *r
256 greg 2.38 )
257 greg 1.1 {
258 greg 2.62 SRCREC *sp;
259 greg 1.1
260 greg 1.35 sp = &source[r->rsrc];
261     if (sp->sflags & SVIRTUAL) { /* virtual source */
262     /* check intersection */
263     if (!(*ofun[sp->so->otype].funp)(sp->so, r))
264     return;
265 greg 2.15 if (!rayshade(r, r->ro->omod)) /* compute contribution */
266     goto nomat;
267 greg 2.19 rayparticipate(r);
268 greg 1.35 return;
269 greg 1.1 }
270 greg 1.35 /* compute intersection */
271     if (sp->sflags & SDISTANT ? sourcehit(r) :
272     (*ofun[sp->so->otype].funp)(sp->so, r)) {
273     if (sp->sa.success >= 0)
274     sp->sa.success++;
275 greg 2.15 if (!rayshade(r, r->ro->omod)) /* compute contribution */
276     goto nomat;
277 greg 2.19 rayparticipate(r);
278 greg 1.35 return;
279 greg 1.1 }
280 greg 2.15 /* we missed our mark! */
281 greg 1.35 if (sp->sa.success < 0)
282     return; /* bitched already */
283     sp->sa.success -= AIMREQT;
284     if (sp->sa.success >= 0)
285     return; /* leniency */
286     sprintf(errmsg, "aiming failure for light source \"%s\"",
287     sp->so->oname);
288     error(WARNING, errmsg); /* issue warning */
289 greg 2.15 return;
290     nomat:
291     objerror(r->ro, USER, "material not found");
292 greg 1.1 }
293    
294    
295 greg 2.47 static int
296     transillum( /* check if material is transparent illum */
297 greg 2.76 OBJREC *m
298 greg 2.47 )
299     {
300 greg 2.76 m = findmaterial(m);
301 greg 2.47 if (m == NULL)
302     return(1);
303     if (m->otype != MAT_ILLUM)
304     return(0);
305     return(!m->oargs.nsargs || !strcmp(m->oargs.sarg[0], VOIDID));
306     }
307    
308    
309 greg 2.62 int
310 greg 2.38 sourcehit( /* check to see if ray hit distant source */
311 greg 2.62 RAY *r
312 greg 2.38 )
313 greg 2.5 {
314 greg 2.47 int glowsrc = -1;
315     int transrc = -1;
316 greg 2.5 int first, last;
317 greg 2.62 int i;
318 greg 2.5
319     if (r->rsrc >= 0) { /* check only one if aimed */
320     first = last = r->rsrc;
321     } else { /* otherwise check all */
322     first = 0; last = nsources-1;
323     }
324 greg 2.47 for (i = first; i <= last; i++) {
325     if ((source[i].sflags & (SDISTANT|SVIRTUAL)) != SDISTANT)
326     continue;
327     /*
328     * Check to see if ray is within
329     * solid angle of source.
330     */
331     if (2.*PI*(1. - DOT(source[i].sloc,r->rdir)) > source[i].ss2)
332     continue;
333     /* is it the only possibility? */
334     if (first == last) {
335     r->ro = source[i].so;
336     break;
337     }
338     /*
339     * If it's a glow or transparent illum, just remember it.
340     */
341     if (source[i].sflags & SSKIP) {
342 greg 2.58 if (glowsrc < 0)
343     glowsrc = i;
344 greg 2.47 continue;
345     }
346 greg 2.76 if (transillum(source[i].so)) {
347 greg 2.58 if (transrc < 0)
348     transrc = i;
349 greg 2.47 continue;
350     }
351     r->ro = source[i].so; /* otherwise, use first hit */
352     break;
353 greg 2.5 }
354 greg 2.47 /*
355     * Do we need fallback?
356     */
357     if (r->ro == NULL) {
358     if (transrc >= 0 && r->crtype & (AMBIENT|SPECULAR))
359     return(0); /* avoid overcounting */
360     if (glowsrc >= 0)
361     r->ro = source[glowsrc].so;
362     else
363     return(0); /* nothing usable */
364     }
365     /*
366 greg 2.75 * Assign object index
367 greg 2.47 */
368     r->robj = objndx(r->ro);
369     return(1);
370 greg 2.5 }
371 greg 2.38
372    
373 greg 1.4 static int
374 greg 2.38 cntcmp( /* contribution compare (descending) */
375 schorsch 2.44 const void *p1,
376     const void *p2
377 greg 2.38 )
378 greg 1.4 {
379 greg 2.62 const CNTPTR *sc1 = (const CNTPTR *)p1;
380     const CNTPTR *sc2 = (const CNTPTR *)p2;
381 greg 2.38
382 greg 1.4 if (sc1->brt > sc2->brt)
383     return(-1);
384     if (sc1->brt < sc2->brt)
385     return(1);
386     return(0);
387     }
388    
389    
390 greg 2.62 void
391 greg 2.38 direct( /* add direct component */
392 schorsch 2.44 RAY *r, /* ray that hit surface */
393     srcdirf_t *f, /* direct component coefficient function */
394     void *p /* data for f */
395 greg 2.38 )
396 greg 1.4 {
397 greg 2.62 int sn;
398     CONTRIB *scp;
399 greg 1.45 SRCINDEX si;
400 greg 1.12 int nshadcheck, ncnts;
401 greg 1.29 int nhits;
402 greg 1.45 double prob, ourthresh, hwt;
403 greg 1.4 RAY sr;
404 greg 2.64
405     /* PMAP: Factor in direct photons (primarily for debugging/validation) */
406     if (directPhotonMapping) {
407     (*f)(r -> rcol, p, r -> ron, PI);
408     multDirectPmap(r);
409     return;
410     }
411    
412 greg 1.25 /* NOTE: srccnt and cntord global so no recursion */
413 greg 1.22 if (nsources <= 0)
414 greg 1.25 return; /* no sources?! */
415 greg 1.4 /* potential contributions */
416 greg 1.45 initsrcindex(&si);
417     for (sn = 0; srcray(&sr, r, &si); sn++) {
418     if (sn >= maxcntr) {
419     maxcntr = sn + MAXSPART;
420 greg 2.32 srccnt = (CONTRIB *)realloc((void *)srccnt,
421 greg 1.45 maxcntr*sizeof(CONTRIB));
422 greg 2.32 cntord = (CNTPTR *)realloc((void *)cntord,
423 greg 1.45 maxcntr*sizeof(CNTPTR));
424 schorsch 2.35 if ((srccnt == NULL) | (cntord == NULL))
425 greg 1.45 error(SYSTEM, "out of memory in direct");
426     }
427     cntord[sn].sndx = sn;
428 greg 2.7 scp = srccnt + sn;
429     scp->sno = sr.rsrc;
430 greg 2.73 #if SHADCACHE /* check shadow cache */
431     if (si.np == 1 && srcblocked(&sr)) {
432     cntord[sn].brt = 0.0;
433     continue;
434     }
435     #endif
436 greg 1.4 /* compute coefficient */
437 greg 2.7 (*f)(scp->coef, p, sr.rdir, si.dom);
438 greg 2.53 cntord[sn].brt = intens(scp->coef);
439 greg 1.15 if (cntord[sn].brt <= 0.0)
440 greg 1.4 continue;
441 greg 2.7 VCOPY(scp->dir, sr.rdir);
442 greg 2.50 copycolor(sr.rcoef, scp->coef);
443 greg 1.35 /* compute potential */
444 greg 2.51 sr.revf = srcvalue;
445     rayvalue(&sr);
446 greg 2.50 multcolor(sr.rcol, sr.rcoef);
447 greg 2.7 copycolor(scp->val, sr.rcol);
448 greg 2.57 cntord[sn].brt = bright(sr.rcol);
449 greg 1.4 }
450     /* sort contributions */
451 greg 1.45 qsort(cntord, sn, sizeof(CNTPTR), cntcmp);
452 greg 1.13 { /* find last */
453 greg 2.62 int l, m;
454 greg 1.13
455 greg 1.45 ncnts = l = sn;
456     sn = 0;
457 greg 1.13 while ((m = (sn + ncnts) >> 1) != l) {
458     if (cntord[m].brt > 0.0)
459     sn = m;
460     else
461     ncnts = m;
462     l = m;
463     }
464     }
465 greg 2.2 if (ncnts == 0)
466     return; /* no contributions! */
467 greg 1.12 /* accumulate tail */
468     for (sn = ncnts-1; sn > 0; sn--)
469     cntord[sn-1].brt += cntord[sn].brt;
470 greg 1.45 /* compute number to check */
471     nshadcheck = pow((double)ncnts, shadcert) + .5;
472     /* modify threshold */
473 greg 2.74 ourthresh = shadthresh / r->rweight;
474 greg 1.10 /* test for shadows */
475 greg 2.13 for (nhits = 0, hwt = 0.0, sn = 0; sn < ncnts;
476     hwt += (double)source[scp->sno].nhits /
477     (double)source[scp->sno].ntests,
478     sn++) {
479 greg 1.10 /* check threshold */
480 greg 2.74 if (sn >= MINSHADCNT &&
481     (sn+nshadcheck>=ncnts ? cntord[sn].brt :
482 greg 1.27 cntord[sn].brt-cntord[sn+nshadcheck].brt)
483 greg 2.74 < ourthresh*bright(r->rcol))
484 greg 1.4 break;
485 greg 2.7 scp = srccnt + cntord[sn].sndx;
486 greg 1.4 /* test for hit */
487 greg 2.52 rayorigin(&sr, SHADOW, r, NULL);
488     copycolor(sr.rcoef, scp->coef);
489 greg 2.7 VCOPY(sr.rdir, scp->dir);
490     sr.rsrc = scp->sno;
491 greg 2.34 /* keep statistics */
492     if (source[scp->sno].ntests++ > 0xfffffff0) {
493     source[scp->sno].ntests >>= 1;
494     source[scp->sno].nhits >>= 1;
495     }
496 greg 1.4 if (localhit(&sr, &thescene) &&
497 greg 2.7 ( sr.ro != source[scp->sno].so ||
498     source[scp->sno].sflags & SFOLLOW )) {
499 greg 1.33 /* follow entire path */
500 greg 2.23 raycont(&sr);
501 greg 1.42 if (trace != NULL)
502     (*trace)(&sr); /* trace execution */
503 greg 2.38 if (bright(sr.rcol) <= FTINY) {
504     #if SHADCACHE
505     if ((scp <= srccnt || scp[-1].sno != scp->sno)
506 greg 2.41 && (scp >= srccnt+ncnts-1 ||
507 greg 2.38 scp[1].sno != scp->sno))
508     srcblocker(&sr);
509     #endif
510 greg 1.4 continue; /* missed! */
511 greg 2.38 }
512 greg 2.55 rayparticipate(&sr);
513 greg 2.51 multcolor(sr.rcol, sr.rcoef);
514 greg 2.7 copycolor(scp->val, sr.rcol);
515 greg 2.51 } else if (trace != NULL &&
516     (source[scp->sno].sflags & (SDISTANT|SVIRTUAL|SFOLLOW))
517     == (SDISTANT|SFOLLOW) &&
518     sourcehit(&sr) && rayshade(&sr, sr.ro->omod)) {
519     (*trace)(&sr); /* trace execution */
520     /* skip call to rayparticipate() & scp->val update */
521 greg 1.4 }
522     /* add contribution if hit */
523 greg 2.7 addcolor(r->rcol, scp->val);
524 greg 1.29 nhits++;
525 greg 2.7 source[scp->sno].nhits++;
526 greg 1.4 }
527 greg 2.13 /* source hit rate */
528     if (hwt > FTINY)
529     hwt = (double)nhits / hwt;
530 greg 1.29 else
531     hwt = 0.5;
532 greg 1.20 #ifdef DEBUG
533 greg 2.13 sprintf(errmsg, "%d tested, %d untested, %f conditional hit rate\n",
534 greg 1.12 sn, ncnts-sn, hwt);
535     eputs(errmsg);
536 greg 1.4 #endif
537     /* add in untested sources */
538 greg 1.12 for ( ; sn < ncnts; sn++) {
539 greg 2.7 scp = srccnt + cntord[sn].sndx;
540     prob = hwt * (double)source[scp->sno].nhits /
541     (double)source[scp->sno].ntests;
542 greg 2.51 if (prob < 1.0)
543     scalecolor(scp->val, prob);
544 greg 2.7 addcolor(r->rcol, scp->val);
545 greg 2.19 }
546     }
547    
548    
549 greg 2.62 void
550 greg 2.38 srcscatter( /* compute source scattering into ray */
551 greg 2.62 RAY *r
552 greg 2.38 )
553 greg 2.19 {
554 greg 2.20 int oldsampndx;
555 greg 2.19 int nsamps;
556     RAY sr;
557     SRCINDEX si;
558 greg 2.25 double t, d;
559     double re, ge, be;
560 greg 2.68 COLOR cvext;
561 greg 2.19 int i, j;
562    
563 greg 2.71 if (r->rot >= FHUGE*.99 || r->gecc >= 1.-FTINY)
564 greg 2.68 return; /* this can never work */
565     /* PMAP: do unconditional inscattering for volume photons */
566     if (!volumePhotonMapping && (r->slights == NULL || r->slights[0] == 0))
567 greg 2.19 return;
568 greg 2.64
569 greg 2.19 if (ssampdist <= FTINY || (nsamps = r->rot/ssampdist + .5) < 1)
570     nsamps = 1;
571 greg 2.22 #if MAXSSAMP
572     else if (nsamps > MAXSSAMP)
573     nsamps = MAXSSAMP;
574     #endif
575 greg 2.20 oldsampndx = samplendx;
576     samplendx = random()&0x7fff; /* randomize */
577 greg 2.68 for (i = volumePhotonMapping ? 1 : r->slights[0]; i > 0; i--) {
578     /* for each source OR once if volume photon map enabled */
579 greg 2.25 for (j = 0; j < nsamps; j++) { /* for each sample position */
580 greg 2.19 samplendx++;
581     t = r->rot * (j+frandom())/nsamps;
582 greg 2.25 /* extinction */
583     re = t*colval(r->cext,RED);
584     ge = t*colval(r->cext,GRN);
585     be = t*colval(r->cext,BLU);
586     setcolor(cvext, re > 92. ? 0. : exp(-re),
587     ge > 92. ? 0. : exp(-ge),
588     be > 92. ? 0. : exp(-be));
589     if (intens(cvext) <= FTINY)
590     break; /* too far away */
591 greg 2.19 sr.rorg[0] = r->rorg[0] + r->rdir[0]*t;
592     sr.rorg[1] = r->rorg[1] + r->rdir[1]*t;
593     sr.rorg[2] = r->rorg[2] + r->rdir[2]*t;
594 greg 2.68
595     if (!volumePhotonMapping) {
596     initsrcindex(&si); /* sample ray to this source */
597     si.sn = r->slights[i];
598     nopart(&si, &sr);
599     if (!srcray(&sr, NULL, &si) ||
600     sr.rsrc != r->slights[i])
601     continue; /* no path */
602 greg 2.45 #if SHADCACHE
603 greg 2.68 if (srcblocked(&sr)) /* check shadow cache */
604     continue;
605 greg 2.45 #endif
606 greg 2.68 copycolor(sr.cext, r->cext);
607     copycolor(sr.albedo, r->albedo);
608     sr.gecc = r->gecc;
609     sr.slights = r->slights;
610     rayvalue(&sr); /* eval. source ray */
611     if (bright(sr.rcol) <= FTINY) {
612 greg 2.45 #if SHADCACHE
613 greg 2.68 srcblocker(&sr); /* add blocker to cache */
614 greg 2.45 #endif
615 greg 2.68 continue;
616     }
617     if (r->gecc <= FTINY) /* compute P(theta) */
618     d = 1.;
619     else {
620     d = DOT(r->rdir, sr.rdir);
621     d = 1. + r->gecc*r->gecc - 2.*r->gecc*d;
622     d = (1. - r->gecc*r->gecc) / (d*sqrt(d));
623     }
624     /* other factors */
625     d *= si.dom * r->rot / (4.*PI*nsamps);
626     scalecolor(sr.rcol, d);
627     } else {
628     /* PMAP: Add ambient inscattering from
629     * volume photons; note we reverse the
630     * incident ray direction since we're
631     * now in *backward* raytracing mode! */
632     sr.rdir [0] = -r -> rdir [0];
633     sr.rdir [1] = -r -> rdir [1];
634     sr.rdir [2] = -r -> rdir [2];
635     sr.gecc = r -> gecc;
636     inscatterVolumePmap(&sr, sr.rcol);
637     scalecolor(sr.rcol, r -> rot / nsamps);
638 greg 2.45 }
639 greg 2.19 multcolor(sr.rcol, r->cext);
640 greg 2.24 multcolor(sr.rcol, r->albedo);
641 greg 2.25 multcolor(sr.rcol, cvext);
642     addcolor(r->rcol, sr.rcol); /* add it in */
643 greg 2.19 }
644 greg 1.1 }
645 greg 2.20 samplendx = oldsampndx;
646 greg 2.4 }
647    
648    
649     /****************************************************************
650     * The following macros were separated from the m_light() routine
651     * because they are very nasty and difficult to understand.
652     */
653    
654 greg 2.11 /* illumblock *
655 greg 2.4 *
656     * We cannot allow an illum to pass to another illum, because that
657     * would almost certainly constitute overcounting.
658     * However, we do allow an illum to pass to another illum
659     * that is actually going to relay to a virtual light source.
660 greg 2.11 * We also prevent an illum from passing to a glow; this provides a
661     * convenient mechanism for defining detailed light source
662     * geometry behind (or inside) an effective radiator.
663 greg 2.4 */
664    
665 greg 2.37 static int
666 greg 2.76 weaksrcmat(OBJREC *m) /* identify material */
667 greg 2.37 {
668 greg 2.76 m = findmaterial(m);
669 greg 2.47 if (m == NULL) return(0);
670     return((m->otype==MAT_ILLUM) | (m->otype==MAT_GLOW));
671 greg 2.37 }
672 greg 2.4
673 greg 2.11 #define illumblock(m, r) (!(source[r->rsrc].sflags&SVIRTUAL) && \
674 greg 2.12 r->rod > 0.0 && \
675 greg 2.76 weaksrcmat(source[r->rsrc].so))
676 greg 2.11
677 greg 2.4 /* wrongsource *
678     *
679     * This source is the wrong source (ie. overcounted) if we are
680     * aimed to a different source than the one we hit and the one
681 greg 2.11 * we hit is not an illum that should be passed.
682 greg 2.4 */
683    
684     #define wrongsource(m, r) (r->rsrc>=0 && source[r->rsrc].so!=r->ro && \
685 greg 2.11 (m->otype!=MAT_ILLUM || illumblock(m,r)))
686 greg 2.4
687     /* distglow *
688     *
689     * A distant glow is an object that sometimes acts as a light source,
690     * but is too far away from the test point to be one in this case.
691 greg 2.11 * (Glows with negative radii should NEVER participate in illumination.)
692 greg 2.4 */
693    
694 greg 2.17 #define distglow(m, r, d) (m->otype==MAT_GLOW && \
695 greg 2.10 m->oargs.farg[3] >= -FTINY && \
696 greg 2.17 d > m->oargs.farg[3])
697 greg 2.4
698     /* badcomponent *
699     *
700     * We must avoid counting light sources in the ambient calculation,
701     * since the direct component is handled separately. Therefore, any
702     * ambient ray which hits an active light source must be discarded.
703     * The same is true for stray specular samples, since the specular
704     * contribution from light sources is calculated separately.
705     */
706 rschregle 2.67 /* PMAP: Also avoid counting sources via transferred ambient rays (e.g.
707     * through glass) when photon mapping is enabled, as these indirect
708     * components are already accounted for.
709     */
710     #define badcomponent(m, r) (srcRayInPmap(r) || \
711     (r->crtype&(AMBIENT|SPECULAR) && \
712 greg 2.4 !(r->crtype&SHADOW || r->rod < 0.0 || \
713 rschregle 2.67 /* not 100% correct */ distglow(m, r, r->rot))))
714 greg 2.4
715     /* passillum *
716     *
717     * An illum passes to another material type when we didn't hit it
718     * on purpose (as part of a direct calculation), or it is relaying
719     * a virtual light source.
720     */
721    
722     #define passillum(m, r) (m->otype==MAT_ILLUM && \
723     (r->rsrc<0 || source[r->rsrc].so!=r->ro || \
724     source[r->rsrc].sflags&SVIRTUAL))
725    
726     /* srcignore *
727     *
728 greg 2.10 * The -dv flag is normally on for sources to be visible.
729 greg 2.4 */
730    
731 greg 2.17 #define srcignore(m, r) !(directvis || r->crtype&SHADOW || \
732     distglow(m, r, raydist(r,PRIMARY)))
733 greg 2.4
734    
735 greg 2.62 int
736 greg 2.38 m_light( /* ray hit a light source */
737 greg 2.62 OBJREC *m,
738     RAY *r
739 greg 2.38 )
740 greg 2.4 {
741     /* check for over-counting */
742 greg 2.50 if (badcomponent(m, r)) {
743     setcolor(r->rcoef, 0.0, 0.0, 0.0);
744 greg 2.14 return(1);
745 greg 2.50 }
746     if (wrongsource(m, r)) {
747     setcolor(r->rcoef, 0.0, 0.0, 0.0);
748 greg 2.14 return(1);
749 greg 2.50 }
750 greg 2.4 /* check for passed illum */
751     if (passillum(m, r)) {
752 greg 2.14 if (m->oargs.nsargs && strcmp(m->oargs.sarg[0], VOIDID))
753 gwlarson 2.28 return(rayshade(r,lastmod(objndx(m),m->oargs.sarg[0])));
754 greg 2.14 raytrans(r);
755     return(1);
756 greg 2.4 }
757 greg 2.50 /* check for invisibility */
758     if (srcignore(m, r)) {
759     setcolor(r->rcoef, 0.0, 0.0, 0.0);
760     return(1);
761     }
762 greg 2.4 /* otherwise treat as source */
763     /* check for behind */
764     if (r->rod < 0.0)
765 greg 2.14 return(1);
766 greg 2.4 /* check for outside spot */
767 greg 2.18 if (m->otype==MAT_SPOT && spotout(r, makespot(m)))
768 greg 2.14 return(1);
769 greg 2.4 /* get distribution pattern */
770     raytexture(r, m->omod);
771     /* get source color */
772     setcolor(r->rcol, m->oargs.farg[0],
773     m->oargs.farg[1],
774     m->oargs.farg[2]);
775     /* modify value */
776     multcolor(r->rcol, r->pcol);
777 greg 2.14 return(1);
778 greg 1.1 }