1 |
/* Copyright (c) 1991 Regents of the University of California */ |
2 |
|
3 |
#ifndef lint |
4 |
static char SCCSid[] = "$SunId$ LBL"; |
5 |
#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 |
#include "octree.h" |
15 |
|
16 |
#include "otypes.h" |
17 |
|
18 |
#include "source.h" |
19 |
|
20 |
#include "random.h" |
21 |
|
22 |
#define MINSAMPLES 16 /* minimum number of pretest samples */ |
23 |
#define STESTMAX 32 /* maximum seeks per sample */ |
24 |
|
25 |
|
26 |
double getdisk(); |
27 |
|
28 |
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 |
if (!issurface(o->otype) || o->omod == OVOID) |
43 |
continue; |
44 |
if (!isvlight(objptr(o->omod)->otype)) |
45 |
continue; |
46 |
if (sfun[o->otype].of == NULL || |
47 |
sfun[o->otype].of->getpleq == NULL) { |
48 |
objerror(o,WARNING,"secondary sources not supported"); |
49 |
continue; |
50 |
} |
51 |
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 |
#ifdef DEBUG |
63 |
fprintf(stderr, "found %d virtual source objects\n", nvobjects); |
64 |
#endif |
65 |
/* append virtual sources */ |
66 |
for (i = nsources; i-- > 0; ) |
67 |
addvirtuals(i, directrelay); |
68 |
/* done with our object list */ |
69 |
free((char *)vobject); |
70 |
nvobjects = 0; |
71 |
} |
72 |
|
73 |
|
74 |
addvirtuals(sn, nr) /* add virtuals associated with source */ |
75 |
int sn; |
76 |
int nr; |
77 |
{ |
78 |
register int i; |
79 |
/* check relay limit first */ |
80 |
if (nr <= 0) |
81 |
return; |
82 |
if (source[sn].sflags & SSKIP) |
83 |
return; |
84 |
/* check each virtual object for projection */ |
85 |
for (i = 0; i < nvobjects; i++) |
86 |
/* vproject() calls us recursively */ |
87 |
vproject(objptr(vobject[i]), sn, nr-1); |
88 |
} |
89 |
|
90 |
|
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[objptr(o->omod)->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 |
int |
119 |
makevsrc(op, sn, pm) /* make virtual source if reasonable */ |
120 |
OBJREC *op; |
121 |
register int sn; |
122 |
MAT4 pm; |
123 |
{ |
124 |
FVECT nsloc, nsnorm, ocent, v; |
125 |
double maxrad2, d; |
126 |
int nsflags; |
127 |
SPOT theirspot, ourspot; |
128 |
register int i; |
129 |
|
130 |
nsflags = source[sn].sflags | (SVIRTUAL|SSPOT|SFOLLOW); |
131 |
/* get object center and max. radius */ |
132 |
maxrad2 = getdisk(ocent, op, sn); |
133 |
if (maxrad2 <= FTINY) /* too small? */ |
134 |
return(-1); |
135 |
/* get location and spot */ |
136 |
if (source[sn].sflags & SDISTANT) { /* distant source */ |
137 |
if (source[sn].sflags & SPROX) |
138 |
return(-1); /* should never get here! */ |
139 |
multv3(nsloc, source[sn].sloc, pm); |
140 |
normalize(nsloc); |
141 |
VCOPY(ourspot.aim, ocent); |
142 |
ourspot.siz = PI*maxrad2; |
143 |
ourspot.flen = 0.; |
144 |
if (source[sn].sflags & SSPOT) { |
145 |
multp3(theirspot.aim, source[sn].sl.s->aim, pm); |
146 |
d = sqrt(dist2(ourspot.aim, theirspot.aim)); |
147 |
d = sqrt(source[sn].sl.s->siz/PI) + d*source[sn].ss; |
148 |
theirspot.siz = PI*d*d; |
149 |
ourspot.flen = theirspot.flen = source[sn].sl.s->flen; |
150 |
d = ourspot.siz; |
151 |
if (!commonbeam(&ourspot, &theirspot, nsloc)) |
152 |
return(-1); /* no overlap */ |
153 |
if (ourspot.siz < d-FTINY) { /* it shrunk */ |
154 |
d = beamdisk(v, op, &ourspot, nsloc); |
155 |
if (d <= FTINY) |
156 |
return(-1); |
157 |
if (d < maxrad2) { |
158 |
maxrad2 = d; |
159 |
VCOPY(ocent, v); |
160 |
} |
161 |
} |
162 |
} |
163 |
} else { /* local source */ |
164 |
multp3(nsloc, source[sn].sloc, pm); |
165 |
for (i = 0; i < 3; i++) |
166 |
ourspot.aim[i] = ocent[i] - nsloc[i]; |
167 |
if ((d = normalize(ourspot.aim)) == 0.) |
168 |
return(-1); /* at source!! */ |
169 |
if (source[sn].sflags & SPROX && d > source[sn].sl.prox) |
170 |
return(-1); /* too far away */ |
171 |
ourspot.flen = 0.; |
172 |
d = (sqrt(maxrad2) + source[sn].ss) / d; |
173 |
if (d < 1.-FTINY) |
174 |
ourspot.siz = 2.*PI*(1. - sqrt(1.-d*d)); |
175 |
else |
176 |
nsflags &= ~SSPOT; |
177 |
if (source[sn].sflags & SSPOT) { |
178 |
copystruct(&theirspot, source[sn].sl.s); |
179 |
multv3(theirspot.aim, source[sn].sl.s->aim, pm); |
180 |
normalize(theirspot.aim); |
181 |
if (nsflags & SSPOT) { |
182 |
ourspot.flen = theirspot.flen; |
183 |
d = ourspot.siz; |
184 |
if (!commonspot(&ourspot, &theirspot, nsloc)) |
185 |
return(-1); /* no overlap */ |
186 |
} else { |
187 |
nsflags |= SSPOT; |
188 |
copystruct(&ourspot, &theirspot); |
189 |
d = 2.*ourspot.siz; |
190 |
} |
191 |
if (ourspot.siz < d-FTINY) { /* it shrunk */ |
192 |
d = spotdisk(v, op, &ourspot, nsloc); |
193 |
if (d <= FTINY) |
194 |
return(-1); |
195 |
if (d < maxrad2) { |
196 |
maxrad2 = d; |
197 |
VCOPY(ocent, v); |
198 |
} |
199 |
} |
200 |
} |
201 |
if (source[sn].sflags & SFLAT) { /* behind source? */ |
202 |
multv3(nsnorm, source[sn].snorm, pm); |
203 |
normalize(nsnorm); |
204 |
if (nsflags & SSPOT && !checkspot(&ourspot, nsnorm)) |
205 |
return(-1); |
206 |
} |
207 |
} |
208 |
/* pretest visibility */ |
209 |
nsflags = vstestvis(nsflags, op, ocent, maxrad2, sn); |
210 |
if (nsflags & SSKIP) |
211 |
return(-1); /* obstructed */ |
212 |
/* it all checks out, so make it */ |
213 |
if ((i = newsource()) < 0) |
214 |
goto memerr; |
215 |
source[i].sflags = nsflags; |
216 |
VCOPY(source[i].sloc, nsloc); |
217 |
if (nsflags & SFLAT) |
218 |
VCOPY(source[i].snorm, nsnorm); |
219 |
source[i].ss = source[sn].ss; source[i].ss2 = source[sn].ss2; |
220 |
if (nsflags & SSPOT) { |
221 |
if ((source[i].sl.s = (SPOT *)malloc(sizeof(SPOT))) == NULL) |
222 |
goto memerr; |
223 |
copystruct(source[i].sl.s, &ourspot); |
224 |
} |
225 |
if (nsflags & SPROX) |
226 |
source[i].sl.prox = source[sn].sl.prox; |
227 |
source[i].sa.sv.sn = sn; |
228 |
source[i].so = op; |
229 |
return(i); |
230 |
memerr: |
231 |
error(SYSTEM, "out of memory in makevsrc"); |
232 |
} |
233 |
|
234 |
|
235 |
double |
236 |
getdisk(oc, op, sn) /* get visible object disk */ |
237 |
FVECT oc; |
238 |
OBJREC *op; |
239 |
register int sn; |
240 |
{ |
241 |
double rad2, roffs, offs, d, rd, rdoto; |
242 |
FVECT rnrm, nrm; |
243 |
/* first, use object getdisk function */ |
244 |
rad2 = getmaxdisk(oc, op); |
245 |
if (!(source[sn].sflags & SVIRTUAL)) |
246 |
return(rad2); /* all done for normal source */ |
247 |
/* check for correct side of relay surface */ |
248 |
roffs = getplaneq(rnrm, source[sn].so); |
249 |
rd = DOT(rnrm, source[sn].sloc); /* source projection */ |
250 |
if (!(source[sn].sflags & SDISTANT)) |
251 |
rd -= roffs; |
252 |
d = DOT(rnrm, oc) - roffs; /* disk distance to relay plane */ |
253 |
if ((d > 0.) ^ (rd > 0.)) |
254 |
return(rad2); /* OK if opposite sides */ |
255 |
if (d*d >= rad2) |
256 |
return(0.); /* no relay is possible */ |
257 |
/* we need a closer look */ |
258 |
offs = getplaneq(nrm, op); |
259 |
rdoto = DOT(rnrm, nrm); |
260 |
if (d*d >= rad2*(1.-rdoto*rdoto)) |
261 |
return(0.); /* disk entirely on projection side */ |
262 |
/* should shrink disk but I'm lazy */ |
263 |
return(rad2); |
264 |
} |
265 |
|
266 |
|
267 |
int |
268 |
vstestvis(f, o, oc, or2, sn) /* pretest source visibility */ |
269 |
int f; /* virtual source flags */ |
270 |
OBJREC *o; /* relay object */ |
271 |
FVECT oc; /* relay object center */ |
272 |
double or2; /* relay object radius squared */ |
273 |
register int sn; /* target source number */ |
274 |
{ |
275 |
RAY sr; |
276 |
FVECT onorm; |
277 |
FVECT offsdir; |
278 |
double or, d; |
279 |
int infront; |
280 |
int stestlim, ssn; |
281 |
int nhit, nok; |
282 |
register int i, n; |
283 |
/* return if pretesting disabled */ |
284 |
if (vspretest <= 0) |
285 |
return(f); |
286 |
/* get surface normal */ |
287 |
getplaneq(onorm, o); |
288 |
/* set number of rays to sample */ |
289 |
if (source[sn].sflags & SDISTANT) { |
290 |
/* 32. == heuristic constant */ |
291 |
n = 32.*or2/(thescene.cusize*thescene.cusize)*vspretest + .5; |
292 |
infront = DOT(onorm, source[sn].sloc) > 0.; |
293 |
} else { |
294 |
for (i = 0; i < 3; i++) |
295 |
offsdir[i] = source[sn].sloc[i] - oc[i]; |
296 |
d = DOT(offsdir,offsdir); |
297 |
if (d <= FTINY) |
298 |
n = 2.*PI * vspretest + .5; |
299 |
else |
300 |
n = 2.*PI * (1.-sqrt(1./(1.+or2/d)))*vspretest + .5; |
301 |
infront = DOT(onorm, offsdir) > 0.; |
302 |
} |
303 |
if (n < MINSAMPLES) n = MINSAMPLES; |
304 |
#ifdef DEBUG |
305 |
fprintf(stderr, "pretesting source %d in object %s with %d rays\n", |
306 |
sn, o->oname, n); |
307 |
#endif |
308 |
/* sample */ |
309 |
or = sqrt(or2); |
310 |
stestlim = n*STESTMAX; |
311 |
ssn = 0; |
312 |
nhit = nok = 0; |
313 |
while (n-- > 0) { |
314 |
/* get sample point */ |
315 |
do { |
316 |
if (ssn >= stestlim) { |
317 |
#ifdef DEBUG |
318 |
fprintf(stderr, "\ttoo hard to hit\n"); |
319 |
#endif |
320 |
return(f); /* too small a target! */ |
321 |
} |
322 |
multisamp(offsdir, 3, urand(sn*931+5827+ssn)); |
323 |
for (i = 0; i < 3; i++) |
324 |
offsdir[i] = or*(1. - 2.*offsdir[i]); |
325 |
ssn++; |
326 |
for (i = 0; i < 3; i++) |
327 |
sr.rorg[i] = oc[i] + offsdir[i]; |
328 |
d = DOT(offsdir,onorm); |
329 |
if (infront) |
330 |
for (i = 0; i < 3; i++) { |
331 |
sr.rorg[i] -= (d-.0001)*onorm[i]; |
332 |
sr.rdir[i] = -onorm[i]; |
333 |
} |
334 |
else |
335 |
for (i = 0; i < 3; i++) { |
336 |
sr.rorg[i] -= (d+.0001)*onorm[i]; |
337 |
sr.rdir[i] = onorm[i]; |
338 |
} |
339 |
rayorigin(&sr, NULL, PRIMARY, 1.0); |
340 |
} while (!(*ofun[o->otype].funp)(o, &sr)); |
341 |
/* check against source */ |
342 |
samplendx++; |
343 |
if (srcray(&sr, NULL, sn) == 0.) |
344 |
continue; |
345 |
sr.revf = srcvalue; |
346 |
rayvalue(&sr); |
347 |
if (bright(sr.rcol) <= FTINY) |
348 |
continue; |
349 |
nok++; |
350 |
/* check against obstructions */ |
351 |
rayclear(&sr); |
352 |
sr.revf = raytrace; |
353 |
rayvalue(&sr); |
354 |
if (bright(sr.rcol) > FTINY) |
355 |
nhit++; |
356 |
if (nhit > 0 && nhit < nok) { |
357 |
#ifdef DEBUG |
358 |
fprintf(stderr, "\tpartially occluded\n"); |
359 |
#endif |
360 |
return(f); /* need to shadow test */ |
361 |
} |
362 |
} |
363 |
if (nhit == 0) { |
364 |
#ifdef DEBUG |
365 |
fprintf(stderr, "\t0%% hit rate\n"); |
366 |
#endif |
367 |
return(f | SSKIP); /* 0% hit rate: totally occluded */ |
368 |
} |
369 |
#ifdef DEBUG |
370 |
fprintf(stderr, "\t100%% hit rate\n"); |
371 |
#endif |
372 |
return(f & ~SFOLLOW); /* 100% hit rate: no occlusion */ |
373 |
} |
374 |
|
375 |
|
376 |
#ifdef DEBUG |
377 |
virtverb(sn, fp) /* print verbose description of virtual source */ |
378 |
register int sn; |
379 |
FILE *fp; |
380 |
{ |
381 |
register int i; |
382 |
|
383 |
fprintf(fp, "%s virtual source %d in %s %s\n", |
384 |
source[sn].sflags & SDISTANT ? "distant" : "local", |
385 |
sn, ofun[source[sn].so->otype].funame, |
386 |
source[sn].so->oname); |
387 |
fprintf(fp, "\tat (%f,%f,%f)\n", |
388 |
source[sn].sloc[0], source[sn].sloc[1], source[sn].sloc[2]); |
389 |
fprintf(fp, "\tlinked to source %d (%s)\n", |
390 |
source[sn].sa.sv.sn, source[source[sn].sa.sv.sn].so->oname); |
391 |
if (source[sn].sflags & SFOLLOW) |
392 |
fprintf(fp, "\talways followed\n"); |
393 |
else |
394 |
fprintf(fp, "\tnever followed\n"); |
395 |
if (!(source[sn].sflags & SSPOT)) |
396 |
return; |
397 |
fprintf(fp, "\twith spot aim (%f,%f,%f) and size %f\n", |
398 |
source[sn].sl.s->aim[0], source[sn].sl.s->aim[1], |
399 |
source[sn].sl.s->aim[2], source[sn].sl.s->siz); |
400 |
} |
401 |
#endif |