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root/radiance/ray/src/rt/virtuals.c
Revision: 2.6
Committed: Mon Aug 10 18:37:06 1998 UTC (25 years, 8 months ago) by gwlarson
Content type: text/plain
Branch: MAIN
Changes since 2.5: +3 -3 lines
Log Message:
changed modifier checking to take most recent definition

File Contents

# User Rev Content
1 gwlarson 2.6 /* Copyright (c) 1998 Silicon Graphics, Inc. */
2 greg 1.1
3     #ifndef lint
4 gwlarson 2.6 static char SCCSid[] = "$SunId$ SGI";
5 greg 1.1 #endif
6    
7     /*
8     * Routines for simulating virtual light sources
9     * Thus far, we only support planar mirrors.
10     */
11    
12     #include "ray.h"
13    
14 greg 1.7 #include "octree.h"
15    
16 greg 1.3 #include "otypes.h"
17    
18 greg 1.1 #include "source.h"
19    
20 greg 1.7 #include "random.h"
21 greg 1.1
22 greg 1.22 #define MINSAMPLES 16 /* minimum number of pretest samples */
23     #define STESTMAX 32 /* maximum seeks per sample */
24 greg 1.1
25 greg 1.13
26 greg 1.7 double getdisk();
27    
28 greg 1.1 static OBJECT *vobject; /* virtual source objects */
29     static int nvobjects = 0; /* number of virtual source objects */
30    
31    
32     markvirtuals() /* find and mark virtual sources */
33     {
34     register OBJREC *o;
35     register int i;
36     /* check number of direct relays */
37     if (directrelay <= 0)
38     return;
39     /* find virtual source objects */
40     for (i = 0; i < nobjects; i++) {
41     o = objptr(i);
42 greg 1.3 if (!issurface(o->otype) || o->omod == OVOID)
43 greg 1.1 continue;
44 greg 1.31 if (!isvlight(vsmaterial(o)->otype))
45 greg 1.1 continue;
46 greg 1.3 if (sfun[o->otype].of == NULL ||
47 greg 1.21 sfun[o->otype].of->getpleq == NULL) {
48     objerror(o,WARNING,"secondary sources not supported");
49     continue;
50     }
51 greg 1.1 if (nvobjects == 0)
52     vobject = (OBJECT *)malloc(sizeof(OBJECT));
53     else
54     vobject = (OBJECT *)realloc((char *)vobject,
55     (unsigned)(nvobjects+1)*sizeof(OBJECT));
56     if (vobject == NULL)
57     error(SYSTEM, "out of memory in addvirtuals");
58     vobject[nvobjects++] = i;
59     }
60     if (nvobjects == 0)
61     return;
62 greg 1.4 #ifdef DEBUG
63     fprintf(stderr, "found %d virtual source objects\n", nvobjects);
64     #endif
65 greg 1.1 /* append virtual sources */
66     for (i = nsources; i-- > 0; )
67 greg 1.7 addvirtuals(i, directrelay);
68 greg 1.1 /* done with our object list */
69     free((char *)vobject);
70     nvobjects = 0;
71     }
72    
73    
74 greg 1.4 addvirtuals(sn, nr) /* add virtuals associated with source */
75     int sn;
76 greg 1.1 int nr;
77     {
78     register int i;
79     /* check relay limit first */
80     if (nr <= 0)
81     return;
82 greg 1.7 if (source[sn].sflags & SSKIP)
83     return;
84 greg 1.1 /* check each virtual object for projection */
85     for (i = 0; i < nvobjects; i++)
86 greg 1.3 /* vproject() calls us recursively */
87 greg 1.4 vproject(objptr(vobject[i]), sn, nr-1);
88 greg 1.1 }
89    
90    
91 greg 1.4 vproject(o, sn, n) /* create projected source(s) if they exist */
92 greg 1.3 OBJREC *o;
93 greg 1.4 int sn;
94 greg 1.3 int n;
95     {
96     register int i;
97     register VSMATERIAL *vsmat;
98     MAT4 proj;
99 greg 1.4 int ns;
100    
101     if (o == source[sn].so) /* objects cannot project themselves */
102     return;
103 greg 1.3 /* get virtual source material */
104 greg 1.31 vsmat = sfun[vsmaterial(o)->otype].mf;
105 greg 1.3 /* project virtual sources */
106     for (i = 0; i < vsmat->nproj; i++)
107 greg 1.4 if ((*vsmat->vproj)(proj, o, &source[sn], i))
108     if ((ns = makevsrc(o, sn, proj)) >= 0) {
109 greg 1.17 source[ns].sa.sv.pn = i;
110 greg 1.4 #ifdef DEBUG
111 greg 1.6 virtverb(ns, stderr);
112 greg 1.4 #endif
113 greg 1.3 addvirtuals(ns, n);
114 greg 1.4 }
115 greg 1.31 }
116    
117    
118     OBJREC *
119     vsmaterial(o) /* get virtual source material pointer */
120     OBJREC *o;
121     {
122     register int i;
123     register OBJREC *m;
124    
125     i = o->omod;
126     m = objptr(i);
127     if (m->otype != MAT_ILLUM || m->oargs.nsargs < 1 ||
128     !strcmp(m->oargs.sarg[0], VOIDID) ||
129 gwlarson 2.6 (i = lastmod(objndx(m), m->oargs.sarg[0])) == OVOID)
130 greg 1.31 return(m); /* direct modifier */
131     return(objptr(i)); /* illum alternate */
132 greg 1.3 }
133    
134    
135 greg 1.4 int
136     makevsrc(op, sn, pm) /* make virtual source if reasonable */
137 greg 1.1 OBJREC *op;
138 greg 1.4 register int sn;
139 greg 1.1 MAT4 pm;
140     {
141 greg 1.9 FVECT nsloc, nsnorm, ocent, v;
142     double maxrad2, d;
143 greg 1.3 int nsflags;
144 greg 1.1 SPOT theirspot, ourspot;
145     register int i;
146 greg 1.3
147 greg 1.6 nsflags = source[sn].sflags | (SVIRTUAL|SSPOT|SFOLLOW);
148 greg 1.1 /* get object center and max. radius */
149 greg 1.6 maxrad2 = getdisk(ocent, op, sn);
150     if (maxrad2 <= FTINY) /* too small? */
151     return(-1);
152 greg 1.1 /* get location and spot */
153 greg 1.4 if (source[sn].sflags & SDISTANT) { /* distant source */
154     if (source[sn].sflags & SPROX)
155 greg 1.5 return(-1); /* should never get here! */
156 greg 1.4 multv3(nsloc, source[sn].sloc, pm);
157 greg 1.17 normalize(nsloc);
158 greg 1.6 VCOPY(ourspot.aim, ocent);
159     ourspot.siz = PI*maxrad2;
160 greg 2.5 ourspot.flen = -1.;
161 greg 1.4 if (source[sn].sflags & SSPOT) {
162     multp3(theirspot.aim, source[sn].sl.s->aim, pm);
163 greg 1.29 /* adjust for source size */
164 greg 1.19 d = sqrt(dist2(ourspot.aim, theirspot.aim));
165 greg 1.28 d = sqrt(source[sn].sl.s->siz/PI) + d*source[sn].srad;
166 greg 1.19 theirspot.siz = PI*d*d;
167     ourspot.flen = theirspot.flen = source[sn].sl.s->flen;
168 greg 1.9 d = ourspot.siz;
169 greg 1.6 if (!commonbeam(&ourspot, &theirspot, nsloc))
170 greg 1.9 return(-1); /* no overlap */
171     if (ourspot.siz < d-FTINY) { /* it shrunk */
172     d = beamdisk(v, op, &ourspot, nsloc);
173     if (d <= FTINY)
174     return(-1);
175     if (d < maxrad2) {
176     maxrad2 = d;
177     VCOPY(ocent, v);
178     }
179     }
180 greg 1.1 }
181     } else { /* local source */
182 greg 1.4 multp3(nsloc, source[sn].sloc, pm);
183 greg 1.6 for (i = 0; i < 3; i++)
184     ourspot.aim[i] = ocent[i] - nsloc[i];
185 greg 1.9 if ((d = normalize(ourspot.aim)) == 0.)
186 greg 1.6 return(-1); /* at source!! */
187 greg 1.9 if (source[sn].sflags & SPROX && d > source[sn].sl.prox)
188 greg 1.6 return(-1); /* too far away */
189     ourspot.flen = 0.;
190 greg 1.29 /* adjust for source size */
191 greg 1.28 d = (sqrt(maxrad2) + source[sn].srad) / d;
192 greg 1.19 if (d < 1.-FTINY)
193     ourspot.siz = 2.*PI*(1. - sqrt(1.-d*d));
194 greg 1.14 else
195     nsflags &= ~SSPOT;
196 greg 1.4 if (source[sn].sflags & SSPOT) {
197     copystruct(&theirspot, source[sn].sl.s);
198     multv3(theirspot.aim, source[sn].sl.s->aim, pm);
199 greg 1.17 normalize(theirspot.aim);
200 greg 1.14 if (nsflags & SSPOT) {
201     ourspot.flen = theirspot.flen;
202     d = ourspot.siz;
203     if (!commonspot(&ourspot, &theirspot, nsloc))
204     return(-1); /* no overlap */
205     } else {
206     nsflags |= SSPOT;
207     copystruct(&ourspot, &theirspot);
208     d = 2.*ourspot.siz;
209     }
210 greg 1.9 if (ourspot.siz < d-FTINY) { /* it shrunk */
211     d = spotdisk(v, op, &ourspot, nsloc);
212     if (d <= FTINY)
213     return(-1);
214     if (d < maxrad2) {
215     maxrad2 = d;
216     VCOPY(ocent, v);
217     }
218     }
219 greg 1.1 }
220 greg 1.4 if (source[sn].sflags & SFLAT) { /* behind source? */
221     multv3(nsnorm, source[sn].snorm, pm);
222 greg 1.17 normalize(nsnorm);
223 greg 1.20 if (nsflags & SSPOT && !checkspot(&ourspot, nsnorm))
224 greg 1.5 return(-1);
225 greg 1.1 }
226     }
227 greg 1.7 /* pretest visibility */
228     nsflags = vstestvis(nsflags, op, ocent, maxrad2, sn);
229     if (nsflags & SSKIP)
230     return(-1); /* obstructed */
231     /* it all checks out, so make it */
232 greg 1.6 if ((i = newsource()) < 0)
233 greg 1.1 goto memerr;
234 greg 1.6 source[i].sflags = nsflags;
235     VCOPY(source[i].sloc, nsloc);
236 greg 1.28 multv3(source[i].ss[SU], source[sn].ss[SU], pm);
237     multv3(source[i].ss[SV], source[sn].ss[SV], pm);
238 greg 1.3 if (nsflags & SFLAT)
239 greg 1.6 VCOPY(source[i].snorm, nsnorm);
240 greg 1.28 else
241     multv3(source[i].ss[SW], source[sn].ss[SW], pm);
242 greg 1.29 source[i].srad = source[sn].srad;
243 greg 1.28 source[i].ss2 = source[sn].ss2;
244 greg 1.14 if (nsflags & SSPOT) {
245     if ((source[i].sl.s = (SPOT *)malloc(sizeof(SPOT))) == NULL)
246     goto memerr;
247     copystruct(source[i].sl.s, &ourspot);
248     }
249 greg 1.3 if (nsflags & SPROX)
250 greg 1.6 source[i].sl.prox = source[sn].sl.prox;
251 greg 1.17 source[i].sa.sv.sn = sn;
252 greg 1.6 source[i].so = op;
253     return(i);
254 greg 1.1 memerr:
255     error(SYSTEM, "out of memory in makevsrc");
256     }
257    
258    
259 greg 1.6 double
260     getdisk(oc, op, sn) /* get visible object disk */
261     FVECT oc;
262     OBJREC *op;
263     register int sn;
264     {
265     double rad2, roffs, offs, d, rd, rdoto;
266     FVECT rnrm, nrm;
267     /* first, use object getdisk function */
268 greg 1.9 rad2 = getmaxdisk(oc, op);
269 greg 1.6 if (!(source[sn].sflags & SVIRTUAL))
270     return(rad2); /* all done for normal source */
271     /* check for correct side of relay surface */
272 greg 1.9 roffs = getplaneq(rnrm, source[sn].so);
273 greg 1.6 rd = DOT(rnrm, source[sn].sloc); /* source projection */
274     if (!(source[sn].sflags & SDISTANT))
275     rd -= roffs;
276     d = DOT(rnrm, oc) - roffs; /* disk distance to relay plane */
277     if ((d > 0.) ^ (rd > 0.))
278     return(rad2); /* OK if opposite sides */
279     if (d*d >= rad2)
280 greg 1.9 return(0.); /* no relay is possible */
281 greg 1.6 /* we need a closer look */
282 greg 1.9 offs = getplaneq(nrm, op);
283 greg 1.6 rdoto = DOT(rnrm, nrm);
284     if (d*d >= rad2*(1.-rdoto*rdoto))
285     return(0.); /* disk entirely on projection side */
286     /* should shrink disk but I'm lazy */
287     return(rad2);
288     }
289    
290    
291 greg 1.7 int
292     vstestvis(f, o, oc, or2, sn) /* pretest source visibility */
293     int f; /* virtual source flags */
294     OBJREC *o; /* relay object */
295     FVECT oc; /* relay object center */
296     double or2; /* relay object radius squared */
297     register int sn; /* target source number */
298 greg 1.1 {
299 greg 1.7 RAY sr;
300     FVECT onorm;
301     FVECT offsdir;
302 greg 1.28 SRCINDEX si;
303 greg 1.7 double or, d;
304 greg 1.16 int stestlim, ssn;
305 greg 1.11 int nhit, nok;
306 greg 1.7 register int i, n;
307     /* return if pretesting disabled */
308     if (vspretest <= 0)
309     return(f);
310     /* get surface normal */
311 greg 1.9 getplaneq(onorm, o);
312 greg 1.7 /* set number of rays to sample */
313 greg 1.8 if (source[sn].sflags & SDISTANT) {
314 greg 1.26 /* 32. == heuristic constant */
315     n = 32.*or2/(thescene.cusize*thescene.cusize)*vspretest + .5;
316 greg 1.8 } else {
317     for (i = 0; i < 3; i++)
318     offsdir[i] = source[sn].sloc[i] - oc[i];
319 greg 1.20 d = DOT(offsdir,offsdir);
320     if (d <= FTINY)
321     n = 2.*PI * vspretest + .5;
322     else
323     n = 2.*PI * (1.-sqrt(1./(1.+or2/d)))*vspretest + .5;
324 greg 1.8 }
325 greg 1.13 if (n < MINSAMPLES) n = MINSAMPLES;
326 greg 1.9 #ifdef DEBUG
327     fprintf(stderr, "pretesting source %d in object %s with %d rays\n",
328     sn, o->oname, n);
329     #endif
330 greg 1.7 /* sample */
331 greg 1.8 or = sqrt(or2);
332 greg 1.16 stestlim = n*STESTMAX;
333     ssn = 0;
334 greg 1.11 nhit = nok = 0;
335 greg 2.4 initsrcindex(&si);
336 greg 1.7 while (n-- > 0) {
337 greg 1.8 /* get sample point */
338     do {
339 greg 1.16 if (ssn >= stestlim) {
340 greg 1.9 #ifdef DEBUG
341     fprintf(stderr, "\ttoo hard to hit\n");
342     #endif
343 greg 1.8 return(f); /* too small a target! */
344 greg 1.9 }
345 greg 1.25 multisamp(offsdir, 3, urand(sn*931+5827+ssn));
346 greg 1.8 for (i = 0; i < 3; i++)
347 greg 1.23 offsdir[i] = or*(1. - 2.*offsdir[i]);
348 greg 1.16 ssn++;
349 greg 2.4 d = 1. - DOT(offsdir, onorm);
350     for (i = 0; i < 3; i++) {
351     sr.rorg[i] = oc[i] + offsdir[i] + d*onorm[i];
352     sr.rdir[i] = -onorm[i];
353     }
354 greg 2.3 sr.rmax = 0.0;
355 greg 1.8 rayorigin(&sr, NULL, PRIMARY, 1.0);
356     } while (!(*ofun[o->otype].funp)(o, &sr));
357     /* check against source */
358 greg 2.4 VCOPY(sr.rorg, sr.rop); /* starting from intersection */
359 greg 1.7 samplendx++;
360 greg 2.4 if (si.sp >= si.np-1 ||
361     !srcray(&sr, NULL, &si) || sr.rsrc != sn) {
362     si.sn = sn-1; /* reset index to our source */
363     si.np = 0;
364     if (!srcray(&sr, NULL, &si) || sr.rsrc != sn)
365     continue; /* can't get there from here */
366     }
367 greg 1.7 sr.revf = srcvalue;
368 greg 2.4 rayvalue(&sr); /* check sample validity */
369 greg 1.7 if (bright(sr.rcol) <= FTINY)
370     continue;
371 greg 2.4 nok++; /* got sample; check obstructions */
372 greg 1.18 rayclear(&sr);
373 greg 1.27 sr.revf = raytrace;
374     rayvalue(&sr);
375     if (bright(sr.rcol) > FTINY)
376 greg 1.11 nhit++;
377     if (nhit > 0 && nhit < nok) {
378 greg 1.9 #ifdef DEBUG
379 greg 1.11 fprintf(stderr, "\tpartially occluded\n");
380 greg 1.9 #endif
381 greg 1.11 return(f); /* need to shadow test */
382     }
383 greg 1.1 }
384 greg 1.9 if (nhit == 0) {
385     #ifdef DEBUG
386     fprintf(stderr, "\t0%% hit rate\n");
387     #endif
388 greg 1.7 return(f | SSKIP); /* 0% hit rate: totally occluded */
389 greg 1.9 }
390     #ifdef DEBUG
391     fprintf(stderr, "\t100%% hit rate\n");
392     #endif
393     return(f & ~SFOLLOW); /* 100% hit rate: no occlusion */
394 greg 1.1 }
395 greg 1.7
396 greg 1.4
397     #ifdef DEBUG
398 greg 1.6 virtverb(sn, fp) /* print verbose description of virtual source */
399     register int sn;
400 greg 1.4 FILE *fp;
401     {
402     register int i;
403    
404     fprintf(fp, "%s virtual source %d in %s %s\n",
405 greg 1.6 source[sn].sflags & SDISTANT ? "distant" : "local",
406     sn, ofun[source[sn].so->otype].funame,
407     source[sn].so->oname);
408 greg 1.4 fprintf(fp, "\tat (%f,%f,%f)\n",
409 greg 1.6 source[sn].sloc[0], source[sn].sloc[1], source[sn].sloc[2]);
410 greg 1.4 fprintf(fp, "\tlinked to source %d (%s)\n",
411 greg 1.17 source[sn].sa.sv.sn, source[source[sn].sa.sv.sn].so->oname);
412 greg 1.6 if (source[sn].sflags & SFOLLOW)
413 greg 1.4 fprintf(fp, "\talways followed\n");
414     else
415     fprintf(fp, "\tnever followed\n");
416 greg 1.6 if (!(source[sn].sflags & SSPOT))
417 greg 1.4 return;
418     fprintf(fp, "\twith spot aim (%f,%f,%f) and size %f\n",
419 greg 1.6 source[sn].sl.s->aim[0], source[sn].sl.s->aim[1],
420     source[sn].sl.s->aim[2], source[sn].sl.s->siz);
421 greg 1.4 }
422     #endif