1 |
#ifndef lint |
2 |
static const char RCSid[] = "$Id: virtuals.c,v 2.12 2004/03/01 18:11:20 greg Exp $"; |
3 |
#endif |
4 |
/* |
5 |
* Routines for simulating virtual light sources |
6 |
* Thus far, we only support planar mirrors. |
7 |
* |
8 |
* External symbols declared in source.h |
9 |
*/ |
10 |
|
11 |
#include "copyright.h" |
12 |
|
13 |
#include "ray.h" |
14 |
|
15 |
#include "otypes.h" |
16 |
|
17 |
#include "source.h" |
18 |
|
19 |
#include "random.h" |
20 |
|
21 |
#define MINSAMPLES 16 /* minimum number of pretest samples */ |
22 |
#define STESTMAX 32 /* maximum seeks per sample */ |
23 |
|
24 |
|
25 |
static OBJECT *vobject; /* virtual source objects */ |
26 |
static int nvobjects = 0; /* number of virtual source objects */ |
27 |
|
28 |
|
29 |
void |
30 |
markvirtuals() /* find and mark virtual sources */ |
31 |
{ |
32 |
register OBJREC *o; |
33 |
register int i; |
34 |
/* check number of direct relays */ |
35 |
if (directrelay <= 0) |
36 |
return; |
37 |
/* find virtual source objects */ |
38 |
for (i = 0; i < nsceneobjs; i++) { |
39 |
o = objptr(i); |
40 |
if (!issurface(o->otype) || o->omod == OVOID) |
41 |
continue; |
42 |
if (!isvlight(vsmaterial(o)->otype)) |
43 |
continue; |
44 |
if (sfun[o->otype].of == NULL || |
45 |
sfun[o->otype].of->getpleq == NULL) { |
46 |
objerror(o,WARNING,"secondary sources not supported"); |
47 |
continue; |
48 |
} |
49 |
if (nvobjects == 0) |
50 |
vobject = (OBJECT *)malloc(sizeof(OBJECT)); |
51 |
else |
52 |
vobject = (OBJECT *)realloc((void *)vobject, |
53 |
(unsigned)(nvobjects+1)*sizeof(OBJECT)); |
54 |
if (vobject == NULL) |
55 |
error(SYSTEM, "out of memory in addvirtuals"); |
56 |
vobject[nvobjects++] = i; |
57 |
} |
58 |
if (nvobjects == 0) |
59 |
return; |
60 |
#ifdef DEBUG |
61 |
fprintf(stderr, "found %d virtual source objects\n", nvobjects); |
62 |
#endif |
63 |
/* append virtual sources */ |
64 |
for (i = nsources; i-- > 0; ) |
65 |
addvirtuals(i, directrelay); |
66 |
/* done with our object list */ |
67 |
free((void *)vobject); |
68 |
nvobjects = 0; |
69 |
} |
70 |
|
71 |
|
72 |
void |
73 |
addvirtuals(sn, nr) /* add virtuals associated with source */ |
74 |
int sn; |
75 |
int nr; |
76 |
{ |
77 |
register int i; |
78 |
/* check relay limit first */ |
79 |
if (nr <= 0) |
80 |
return; |
81 |
if (source[sn].sflags & SSKIP) |
82 |
return; |
83 |
/* check each virtual object for projection */ |
84 |
for (i = 0; i < nvobjects; i++) |
85 |
/* vproject() calls us recursively */ |
86 |
vproject(objptr(vobject[i]), sn, nr-1); |
87 |
} |
88 |
|
89 |
|
90 |
void |
91 |
vproject(o, sn, n) /* create projected source(s) if they exist */ |
92 |
OBJREC *o; |
93 |
int sn; |
94 |
int n; |
95 |
{ |
96 |
register int i; |
97 |
register VSMATERIAL *vsmat; |
98 |
MAT4 proj; |
99 |
int ns; |
100 |
|
101 |
if (o == source[sn].so) /* objects cannot project themselves */ |
102 |
return; |
103 |
/* get virtual source material */ |
104 |
vsmat = sfun[vsmaterial(o)->otype].mf; |
105 |
/* project virtual sources */ |
106 |
for (i = 0; i < vsmat->nproj; i++) |
107 |
if ((*vsmat->vproj)(proj, o, &source[sn], i)) |
108 |
if ((ns = makevsrc(o, sn, proj)) >= 0) { |
109 |
source[ns].sa.sv.pn = i; |
110 |
#ifdef DEBUG |
111 |
virtverb(ns, stderr); |
112 |
#endif |
113 |
addvirtuals(ns, n); |
114 |
} |
115 |
} |
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 = findmaterial(objptr(i)); |
127 |
if (m == NULL) |
128 |
return(objptr(i)); |
129 |
if (m->otype != MAT_ILLUM || m->oargs.nsargs < 1 || |
130 |
!strcmp(m->oargs.sarg[0], VOIDID) || |
131 |
(i = lastmod(objndx(m), m->oargs.sarg[0])) == OVOID) |
132 |
return(m); /* direct modifier */ |
133 |
return(objptr(i)); /* illum alternate */ |
134 |
} |
135 |
|
136 |
|
137 |
int |
138 |
makevsrc(op, sn, pm) /* make virtual source if reasonable */ |
139 |
OBJREC *op; |
140 |
register int sn; |
141 |
MAT4 pm; |
142 |
{ |
143 |
FVECT nsloc, nsnorm, ocent, v; |
144 |
double maxrad2, d; |
145 |
int nsflags; |
146 |
SPOT theirspot, ourspot; |
147 |
register int i; |
148 |
|
149 |
nsflags = source[sn].sflags | (SVIRTUAL|SSPOT|SFOLLOW); |
150 |
/* get object center and max. radius */ |
151 |
maxrad2 = getdisk(ocent, op, sn); |
152 |
if (maxrad2 <= FTINY) /* too small? */ |
153 |
return(-1); |
154 |
/* get location and spot */ |
155 |
if (source[sn].sflags & SDISTANT) { /* distant source */ |
156 |
if (source[sn].sflags & SPROX) |
157 |
return(-1); /* should never get here! */ |
158 |
multv3(nsloc, source[sn].sloc, pm); |
159 |
normalize(nsloc); |
160 |
VCOPY(ourspot.aim, ocent); |
161 |
ourspot.siz = PI*maxrad2; |
162 |
ourspot.flen = -1.; |
163 |
if (source[sn].sflags & SSPOT) { |
164 |
multp3(theirspot.aim, source[sn].sl.s->aim, pm); |
165 |
/* adjust for source size */ |
166 |
d = sqrt(dist2(ourspot.aim, theirspot.aim)); |
167 |
d = sqrt(source[sn].sl.s->siz/PI) + d*source[sn].srad; |
168 |
theirspot.siz = PI*d*d; |
169 |
ourspot.flen = theirspot.flen = source[sn].sl.s->flen; |
170 |
d = ourspot.siz; |
171 |
if (!commonbeam(&ourspot, &theirspot, nsloc)) |
172 |
return(-1); /* no overlap */ |
173 |
if (ourspot.siz < d-FTINY) { /* it shrunk */ |
174 |
d = beamdisk(v, op, &ourspot, nsloc); |
175 |
if (d <= FTINY) |
176 |
return(-1); |
177 |
if (d < maxrad2) { |
178 |
maxrad2 = d; |
179 |
VCOPY(ocent, v); |
180 |
} |
181 |
} |
182 |
} |
183 |
} else { /* local source */ |
184 |
multp3(nsloc, source[sn].sloc, pm); |
185 |
for (i = 0; i < 3; i++) |
186 |
ourspot.aim[i] = ocent[i] - nsloc[i]; |
187 |
if ((d = normalize(ourspot.aim)) == 0.) |
188 |
return(-1); /* at source!! */ |
189 |
if (source[sn].sflags & SPROX && d > source[sn].sl.prox) |
190 |
return(-1); /* too far away */ |
191 |
ourspot.flen = 0.; |
192 |
/* adjust for source size */ |
193 |
d = (sqrt(maxrad2) + source[sn].srad) / d; |
194 |
if (d < 1.-FTINY) |
195 |
ourspot.siz = 2.*PI*(1. - sqrt(1.-d*d)); |
196 |
else |
197 |
nsflags &= ~SSPOT; |
198 |
if (source[sn].sflags & SSPOT) { |
199 |
theirspot = *(source[sn].sl.s); |
200 |
multv3(theirspot.aim, source[sn].sl.s->aim, pm); |
201 |
normalize(theirspot.aim); |
202 |
if (nsflags & SSPOT) { |
203 |
ourspot.flen = theirspot.flen; |
204 |
d = ourspot.siz; |
205 |
if (!commonspot(&ourspot, &theirspot, nsloc)) |
206 |
return(-1); /* no overlap */ |
207 |
} else { |
208 |
nsflags |= SSPOT; |
209 |
ourspot = theirspot; |
210 |
d = 2.*ourspot.siz; |
211 |
} |
212 |
if (ourspot.siz < d-FTINY) { /* it shrunk */ |
213 |
d = spotdisk(v, op, &ourspot, nsloc); |
214 |
if (d <= FTINY) |
215 |
return(-1); |
216 |
if (d < maxrad2) { |
217 |
maxrad2 = d; |
218 |
VCOPY(ocent, v); |
219 |
} |
220 |
} |
221 |
} |
222 |
if (source[sn].sflags & SFLAT) { /* behind source? */ |
223 |
multv3(nsnorm, source[sn].snorm, pm); |
224 |
normalize(nsnorm); |
225 |
if (nsflags & SSPOT && !checkspot(&ourspot, nsnorm)) |
226 |
return(-1); |
227 |
} |
228 |
} |
229 |
/* pretest visibility */ |
230 |
nsflags = vstestvis(nsflags, op, ocent, maxrad2, sn); |
231 |
if (nsflags & SSKIP) |
232 |
return(-1); /* obstructed */ |
233 |
/* it all checks out, so make it */ |
234 |
if ((i = newsource()) < 0) |
235 |
goto memerr; |
236 |
source[i].sflags = nsflags; |
237 |
VCOPY(source[i].sloc, nsloc); |
238 |
multv3(source[i].ss[SU], source[sn].ss[SU], pm); |
239 |
multv3(source[i].ss[SV], source[sn].ss[SV], pm); |
240 |
if (nsflags & SFLAT) |
241 |
VCOPY(source[i].snorm, nsnorm); |
242 |
else |
243 |
multv3(source[i].ss[SW], source[sn].ss[SW], pm); |
244 |
source[i].srad = source[sn].srad; |
245 |
source[i].ss2 = source[sn].ss2; |
246 |
if (nsflags & SSPOT) { |
247 |
if ((source[i].sl.s = (SPOT *)malloc(sizeof(SPOT))) == NULL) |
248 |
goto memerr; |
249 |
*(source[i].sl.s) = ourspot; |
250 |
} |
251 |
if (nsflags & SPROX) |
252 |
source[i].sl.prox = source[sn].sl.prox; |
253 |
source[i].sa.sv.sn = sn; |
254 |
source[i].so = op; |
255 |
return(i); |
256 |
memerr: |
257 |
error(SYSTEM, "out of memory in makevsrc"); |
258 |
} |
259 |
|
260 |
|
261 |
double |
262 |
getdisk(oc, op, sn) /* get visible object disk */ |
263 |
FVECT oc; |
264 |
OBJREC *op; |
265 |
register int sn; |
266 |
{ |
267 |
double rad2, roffs, offs, d, rd, rdoto; |
268 |
FVECT rnrm, nrm; |
269 |
/* first, use object getdisk function */ |
270 |
rad2 = getmaxdisk(oc, op); |
271 |
if (!(source[sn].sflags & SVIRTUAL)) |
272 |
return(rad2); /* all done for normal source */ |
273 |
/* check for correct side of relay surface */ |
274 |
roffs = getplaneq(rnrm, source[sn].so); |
275 |
rd = DOT(rnrm, source[sn].sloc); /* source projection */ |
276 |
if (!(source[sn].sflags & SDISTANT)) |
277 |
rd -= roffs; |
278 |
d = DOT(rnrm, oc) - roffs; /* disk distance to relay plane */ |
279 |
if ((d > 0.) ^ (rd > 0.)) |
280 |
return(rad2); /* OK if opposite sides */ |
281 |
if (d*d >= rad2) |
282 |
return(0.); /* no relay is possible */ |
283 |
/* we need a closer look */ |
284 |
offs = getplaneq(nrm, op); |
285 |
rdoto = DOT(rnrm, nrm); |
286 |
if (d*d >= rad2*(1.-rdoto*rdoto)) |
287 |
return(0.); /* disk entirely on projection side */ |
288 |
/* should shrink disk but I'm lazy */ |
289 |
return(rad2); |
290 |
} |
291 |
|
292 |
|
293 |
int |
294 |
vstestvis(f, o, oc, or2, sn) /* pretest source visibility */ |
295 |
int f; /* virtual source flags */ |
296 |
OBJREC *o; /* relay object */ |
297 |
FVECT oc; /* relay object center */ |
298 |
double or2; /* relay object radius squared */ |
299 |
register int sn; /* target source number */ |
300 |
{ |
301 |
RAY sr; |
302 |
FVECT onorm; |
303 |
FVECT offsdir; |
304 |
SRCINDEX si; |
305 |
double or, d; |
306 |
int stestlim, ssn; |
307 |
int nhit, nok; |
308 |
register int i, n; |
309 |
/* return if pretesting disabled */ |
310 |
if (vspretest <= 0) |
311 |
return(f); |
312 |
/* get surface normal */ |
313 |
getplaneq(onorm, o); |
314 |
/* set number of rays to sample */ |
315 |
if (source[sn].sflags & SDISTANT) { |
316 |
/* 32. == heuristic constant */ |
317 |
n = 32.*or2/(thescene.cusize*thescene.cusize)*vspretest + .5; |
318 |
} else { |
319 |
for (i = 0; i < 3; i++) |
320 |
offsdir[i] = source[sn].sloc[i] - oc[i]; |
321 |
d = DOT(offsdir,offsdir); |
322 |
if (d <= FTINY) |
323 |
n = 2.*PI * vspretest + .5; |
324 |
else |
325 |
n = 2.*PI * (1.-sqrt(1./(1.+or2/d)))*vspretest + .5; |
326 |
} |
327 |
if (n < MINSAMPLES) n = MINSAMPLES; |
328 |
#ifdef DEBUG |
329 |
fprintf(stderr, "pretesting source %d in object %s with %d rays\n", |
330 |
sn, o->oname, n); |
331 |
#endif |
332 |
/* sample */ |
333 |
or = sqrt(or2); |
334 |
stestlim = n*STESTMAX; |
335 |
ssn = 0; |
336 |
nhit = nok = 0; |
337 |
initsrcindex(&si); |
338 |
while (n-- > 0) { |
339 |
/* get sample point */ |
340 |
do { |
341 |
if (ssn >= stestlim) { |
342 |
#ifdef DEBUG |
343 |
fprintf(stderr, "\ttoo hard to hit\n"); |
344 |
#endif |
345 |
return(f); /* too small a target! */ |
346 |
} |
347 |
multisamp(offsdir, 3, urand(sn*931+5827+ssn)); |
348 |
for (i = 0; i < 3; i++) |
349 |
offsdir[i] = or*(1. - 2.*offsdir[i]); |
350 |
ssn++; |
351 |
d = 1. - DOT(offsdir, onorm); |
352 |
for (i = 0; i < 3; i++) { |
353 |
sr.rorg[i] = oc[i] + offsdir[i] + d*onorm[i]; |
354 |
sr.rdir[i] = -onorm[i]; |
355 |
} |
356 |
sr.rmax = 0.0; |
357 |
rayorigin(&sr, NULL, PRIMARY, 1.0); |
358 |
} while (!(*ofun[o->otype].funp)(o, &sr)); |
359 |
/* check against source */ |
360 |
VCOPY(sr.rorg, sr.rop); /* starting from intersection */ |
361 |
samplendx++; |
362 |
if (si.sp >= si.np-1 || |
363 |
!srcray(&sr, NULL, &si) || sr.rsrc != sn) { |
364 |
si.sn = sn-1; /* reset index to our source */ |
365 |
si.np = 0; |
366 |
if (!srcray(&sr, NULL, &si) || sr.rsrc != sn) |
367 |
continue; /* can't get there from here */ |
368 |
} |
369 |
sr.revf = srcvalue; |
370 |
rayvalue(&sr); /* check sample validity */ |
371 |
if (bright(sr.rcol) <= FTINY) |
372 |
continue; |
373 |
nok++; /* got sample; check obstructions */ |
374 |
rayclear(&sr); |
375 |
sr.revf = raytrace; |
376 |
rayvalue(&sr); |
377 |
if (bright(sr.rcol) > FTINY) |
378 |
nhit++; |
379 |
if (nhit > 0 && nhit < nok) { |
380 |
#ifdef DEBUG |
381 |
fprintf(stderr, "\tpartially occluded\n"); |
382 |
#endif |
383 |
return(f); /* need to shadow test */ |
384 |
} |
385 |
} |
386 |
if (nhit == 0) { |
387 |
#ifdef DEBUG |
388 |
fprintf(stderr, "\t0%% hit rate\n"); |
389 |
#endif |
390 |
return(f | SSKIP); /* 0% hit rate: totally occluded */ |
391 |
} |
392 |
#ifdef DEBUG |
393 |
fprintf(stderr, "\t100%% hit rate\n"); |
394 |
#endif |
395 |
return(f & ~SFOLLOW); /* 100% hit rate: no occlusion */ |
396 |
} |
397 |
|
398 |
|
399 |
#ifdef DEBUG |
400 |
void |
401 |
virtverb(sn, fp) /* print verbose description of virtual source */ |
402 |
register int sn; |
403 |
FILE *fp; |
404 |
{ |
405 |
register int i; |
406 |
|
407 |
fprintf(fp, "%s virtual source %d in %s %s\n", |
408 |
source[sn].sflags & SDISTANT ? "distant" : "local", |
409 |
sn, ofun[source[sn].so->otype].funame, |
410 |
source[sn].so->oname); |
411 |
fprintf(fp, "\tat (%f,%f,%f)\n", |
412 |
source[sn].sloc[0], source[sn].sloc[1], source[sn].sloc[2]); |
413 |
fprintf(fp, "\tlinked to source %d (%s)\n", |
414 |
source[sn].sa.sv.sn, source[source[sn].sa.sv.sn].so->oname); |
415 |
if (source[sn].sflags & SFOLLOW) |
416 |
fprintf(fp, "\talways followed\n"); |
417 |
else |
418 |
fprintf(fp, "\tnever followed\n"); |
419 |
if (!(source[sn].sflags & SSPOT)) |
420 |
return; |
421 |
fprintf(fp, "\twith spot aim (%f,%f,%f) and size %f\n", |
422 |
source[sn].sl.s->aim[0], source[sn].sl.s->aim[1], |
423 |
source[sn].sl.s->aim[2], source[sn].sl.s->siz); |
424 |
} |
425 |
#endif |