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root/radiance/ray/src/cv/bsdfrep.c
Revision: 2.15
Committed: Sat Oct 19 00:11:50 2013 UTC (10 years, 6 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.14: +2 -2 lines
Log Message:
Fixed overflow and tweaked culling operations

File Contents

# Content
1 #ifndef lint
2 static const char RCSid[] = "$Id: bsdfrep.c,v 2.14 2013/09/20 00:21:39 greg Exp $";
3 #endif
4 /*
5 * Support BSDF representation as radial basis functions.
6 *
7 * G. Ward
8 */
9
10 #define _USE_MATH_DEFINES
11 #include <stdlib.h>
12 #include <string.h>
13 #include <math.h>
14 #include "rtio.h"
15 #include "resolu.h"
16 #include "bsdfrep.h"
17 /* active grid resolution */
18 int grid_res = GRIDRES;
19
20 /* coverage/symmetry using INP_QUAD? flags */
21 int inp_coverage = 0;
22 /* all incident angles in-plane so far? */
23 int single_plane_incident = -1;
24
25 /* input/output orientations */
26 int input_orient = 0;
27 int output_orient = 0;
28
29 /* BSDF histogram */
30 unsigned long bsdf_hist[HISTLEN];
31
32 /* BSDF value for boundary regions */
33 double bsdf_min = 0;
34
35 /* processed incident DSF measurements */
36 RBFNODE *dsf_list = NULL;
37
38 /* RBF-linking matrices (edges) */
39 MIGRATION *mig_list = NULL;
40
41 /* current input direction */
42 double theta_in_deg, phi_in_deg;
43
44 /* Register new input direction */
45 int
46 new_input_direction(double new_theta, double new_phi)
47 {
48 if (!input_orient) /* check input orientation */
49 input_orient = 1 - 2*(new_theta > 90.);
50 else if (input_orient > 0 ^ new_theta < 90.) {
51 fprintf(stderr,
52 "%s: Cannot handle input angles on both sides of surface\n",
53 progname);
54 return(0);
55 }
56 /* normalize angle ranges */
57 while (new_theta < -180.)
58 new_theta += 360.;
59 while (new_theta > 180.)
60 new_theta -= 360.;
61 if (new_theta < 0) {
62 new_theta = -new_theta;
63 new_phi += 180.;
64 }
65 if ((theta_in_deg = new_theta) < 1.0)
66 return(1); /* don't rely on phi near normal */
67 while (new_phi < 0)
68 new_phi += 360.;
69 while (new_phi >= 360.)
70 new_phi -= 360.;
71 if (single_plane_incident > 0) /* check input coverage */
72 single_plane_incident = (round(new_phi) == round(phi_in_deg));
73 else if (single_plane_incident < 0)
74 single_plane_incident = 1;
75 phi_in_deg = new_phi;
76 if ((1. < new_phi) & (new_phi < 89.))
77 inp_coverage |= INP_QUAD1;
78 else if ((91. < new_phi) & (new_phi < 179.))
79 inp_coverage |= INP_QUAD2;
80 else if ((181. < new_phi) & (new_phi < 269.))
81 inp_coverage |= INP_QUAD3;
82 else if ((271. < new_phi) & (new_phi < 359.))
83 inp_coverage |= INP_QUAD4;
84 return(1);
85 }
86
87 /* Apply symmetry to the given vector based on distribution */
88 int
89 use_symmetry(FVECT vec)
90 {
91 const double phi = get_phi360(vec);
92
93 switch (inp_coverage) {
94 case INP_QUAD1|INP_QUAD2|INP_QUAD3|INP_QUAD4:
95 break;
96 case INP_QUAD1|INP_QUAD2:
97 if ((-FTINY > phi) | (phi > 180.+FTINY))
98 goto mir_y;
99 break;
100 case INP_QUAD2|INP_QUAD3:
101 if ((90.-FTINY > phi) | (phi > 270.+FTINY))
102 goto mir_x;
103 break;
104 case INP_QUAD3|INP_QUAD4:
105 if ((180.-FTINY > phi) | (phi > 360.+FTINY))
106 goto mir_y;
107 break;
108 case INP_QUAD4|INP_QUAD1:
109 if ((270.-FTINY > phi) & (phi > 90.+FTINY))
110 goto mir_x;
111 break;
112 case INP_QUAD1:
113 if ((-FTINY > phi) | (phi > 90.+FTINY))
114 switch ((int)(phi*(1./90.))) {
115 case 1: goto mir_x;
116 case 2: goto mir_xy;
117 case 3: goto mir_y;
118 }
119 break;
120 case INP_QUAD2:
121 if ((90.-FTINY > phi) | (phi > 180.+FTINY))
122 switch ((int)(phi*(1./90.))) {
123 case 0: goto mir_x;
124 case 2: goto mir_y;
125 case 3: goto mir_xy;
126 }
127 break;
128 case INP_QUAD3:
129 if ((180.-FTINY > phi) | (phi > 270.+FTINY))
130 switch ((int)(phi*(1./90.))) {
131 case 0: goto mir_xy;
132 case 1: goto mir_y;
133 case 3: goto mir_x;
134 }
135 break;
136 case INP_QUAD4:
137 if ((270.-FTINY > phi) | (phi > 360.+FTINY))
138 switch ((int)(phi*(1./90.))) {
139 case 0: goto mir_y;
140 case 1: goto mir_xy;
141 case 2: goto mir_x;
142 }
143 break;
144 default:
145 fprintf(stderr, "%s: Illegal input coverage (%d)\n",
146 progname, inp_coverage);
147 exit(1);
148 }
149 return(0); /* in range */
150 mir_x:
151 vec[0] = -vec[0];
152 return(MIRROR_X);
153 mir_y:
154 vec[1] = -vec[1];
155 return(MIRROR_Y);
156 mir_xy:
157 vec[0] = -vec[0];
158 vec[1] = -vec[1];
159 return(MIRROR_X|MIRROR_Y);
160 }
161
162 /* Reverse symmetry based on what was done before */
163 void
164 rev_symmetry(FVECT vec, int sym)
165 {
166 if (sym & MIRROR_X)
167 vec[0] = -vec[0];
168 if (sym & MIRROR_Y)
169 vec[1] = -vec[1];
170 }
171
172 /* Reverse symmetry for an RBF distribution */
173 void
174 rev_rbf_symmetry(RBFNODE *rbf, int sym)
175 {
176 int n;
177
178 rev_symmetry(rbf->invec, sym);
179 if (sym & MIRROR_X)
180 for (n = rbf->nrbf; n-- > 0; )
181 rbf->rbfa[n].gx = grid_res-1 - rbf->rbfa[n].gx;
182 if (sym & MIRROR_Y)
183 for (n = rbf->nrbf; n-- > 0; )
184 rbf->rbfa[n].gy = grid_res-1 - rbf->rbfa[n].gy;
185 }
186
187 /* Rotate RBF to correspond to given incident vector */
188 void
189 rotate_rbf(RBFNODE *rbf, const FVECT invec)
190 {
191 static const FVECT vnorm = {.0, .0, 1.};
192 const double phi = atan2(invec[1],invec[0]) -
193 atan2(rbf->invec[1],rbf->invec[0]);
194 FVECT outvec;
195 int pos[2];
196 int n;
197
198 for (n = ((-.01 > phi) | (phi > .01))*rbf->nrbf; n-- > 0; ) {
199 ovec_from_pos(outvec, rbf->rbfa[n].gx, rbf->rbfa[n].gy);
200 spinvector(outvec, outvec, vnorm, phi);
201 pos_from_vec(pos, outvec);
202 rbf->rbfa[n].gx = pos[0];
203 rbf->rbfa[n].gy = pos[1];
204 }
205 VCOPY(rbf->invec, invec);
206 }
207
208 /* Compute outgoing vector from grid position */
209 void
210 ovec_from_pos(FVECT vec, int xpos, int ypos)
211 {
212 double uv[2];
213 double r2;
214
215 SDsquare2disk(uv, (xpos+.5)/grid_res, (ypos+.5)/grid_res);
216 /* uniform hemispherical projection */
217 r2 = uv[0]*uv[0] + uv[1]*uv[1];
218 vec[0] = vec[1] = sqrt(2. - r2);
219 vec[0] *= uv[0];
220 vec[1] *= uv[1];
221 vec[2] = output_orient*(1. - r2);
222 }
223
224 /* Compute grid position from normalized input/output vector */
225 void
226 pos_from_vec(int pos[2], const FVECT vec)
227 {
228 double sq[2]; /* uniform hemispherical projection */
229 double norm = 1./sqrt(1. + fabs(vec[2]));
230
231 SDdisk2square(sq, vec[0]*norm, vec[1]*norm);
232
233 pos[0] = (int)(sq[0]*grid_res);
234 pos[1] = (int)(sq[1]*grid_res);
235 }
236
237 /* Compute volume associated with Gaussian lobe */
238 double
239 rbf_volume(const RBFVAL *rbfp)
240 {
241 double rad = R2ANG(rbfp->crad);
242 FVECT odir;
243 double elev, integ;
244 /* infinite integral approximation */
245 integ = (2.*M_PI) * rbfp->peak * rad*rad;
246 /* check if we're near horizon */
247 ovec_from_pos(odir, rbfp->gx, rbfp->gy);
248 elev = output_orient*odir[2];
249 /* apply cut-off correction if > 1% */
250 if (elev < 2.8*rad) {
251 /* elev = asin(elev); /* this is so crude, anyway... */
252 integ *= 1. - .5*exp(-.5*elev*elev/(rad*rad));
253 }
254 return(integ);
255 }
256
257 /* Evaluate RBF for DSF at the given normalized outgoing direction */
258 double
259 eval_rbfrep(const RBFNODE *rp, const FVECT outvec)
260 {
261 double minval = bsdf_min*output_orient*outvec[2];
262 double res = 0;
263 const RBFVAL *rbfp;
264 FVECT odir;
265 double sig2;
266 int n;
267 /* check for wrong side */
268 if (outvec[2] > 0 ^ output_orient > 0)
269 return(.0);
270 /* use minimum if no information avail. */
271 if (rp == NULL)
272 return(minval);
273 /* sum radial basis function */
274 rbfp = rp->rbfa;
275 for (n = rp->nrbf; n--; rbfp++) {
276 ovec_from_pos(odir, rbfp->gx, rbfp->gy);
277 sig2 = R2ANG(rbfp->crad);
278 sig2 = (DOT(odir,outvec) - 1.) / (sig2*sig2);
279 if (sig2 > -19.)
280 res += rbfp->peak * exp(sig2);
281 }
282 if (res < minval) /* never return less than minval */
283 return(minval);
284 return(res);
285 }
286
287 /* Insert a new directional scattering function in our global list */
288 int
289 insert_dsf(RBFNODE *newrbf)
290 {
291 RBFNODE *rbf, *rbf_last;
292 int pos;
293 /* check for redundant meas. */
294 for (rbf = dsf_list; rbf != NULL; rbf = rbf->next)
295 if (DOT(rbf->invec, newrbf->invec) >= 1.-FTINY) {
296 fprintf(stderr,
297 "%s: Duplicate incident measurement (ignored)\n",
298 progname);
299 free(newrbf);
300 return(-1);
301 }
302 /* keep in ascending theta order */
303 for (rbf_last = NULL, rbf = dsf_list; rbf != NULL;
304 rbf_last = rbf, rbf = rbf->next)
305 if (single_plane_incident && input_orient*rbf->invec[2] <
306 input_orient*newrbf->invec[2])
307 break;
308 if (rbf_last == NULL) { /* insert new node in list */
309 newrbf->ord = 0;
310 newrbf->next = dsf_list;
311 dsf_list = newrbf;
312 } else {
313 newrbf->ord = rbf_last->ord + 1;
314 newrbf->next = rbf;
315 rbf_last->next = newrbf;
316 }
317 rbf_last = newrbf;
318 while (rbf != NULL) { /* update ordinal positions */
319 rbf->ord = rbf_last->ord + 1;
320 rbf_last = rbf;
321 rbf = rbf->next;
322 }
323 return(newrbf->ord);
324 }
325
326 /* Get the DSF indicated by its ordinal position */
327 RBFNODE *
328 get_dsf(int ord)
329 {
330 RBFNODE *rbf;
331
332 for (rbf = dsf_list; rbf != NULL; rbf = rbf->next)
333 if (rbf->ord == ord)
334 return(rbf);
335 return(NULL);
336 }
337
338 /* Get triangle surface orientation (unnormalized) */
339 void
340 tri_orient(FVECT vres, const FVECT v1, const FVECT v2, const FVECT v3)
341 {
342 FVECT v2minus1, v3minus2;
343
344 VSUB(v2minus1, v2, v1);
345 VSUB(v3minus2, v3, v2);
346 VCROSS(vres, v2minus1, v3minus2);
347 }
348
349 /* Determine if vertex order is reversed (inward normal) */
350 int
351 is_rev_tri(const FVECT v1, const FVECT v2, const FVECT v3)
352 {
353 FVECT tor;
354
355 tri_orient(tor, v1, v2, v3);
356
357 return(DOT(tor, v2) < 0.);
358 }
359
360 /* Find vertices completing triangles on either side of the given edge */
361 int
362 get_triangles(RBFNODE *rbfv[2], const MIGRATION *mig)
363 {
364 const MIGRATION *ej1, *ej2;
365 RBFNODE *tv;
366
367 rbfv[0] = rbfv[1] = NULL;
368 if (mig == NULL)
369 return(0);
370 for (ej1 = mig->rbfv[0]->ejl; ej1 != NULL;
371 ej1 = nextedge(mig->rbfv[0],ej1)) {
372 if (ej1 == mig)
373 continue;
374 tv = opp_rbf(mig->rbfv[0],ej1);
375 for (ej2 = tv->ejl; ej2 != NULL; ej2 = nextedge(tv,ej2))
376 if (opp_rbf(tv,ej2) == mig->rbfv[1]) {
377 rbfv[is_rev_tri(mig->rbfv[0]->invec,
378 mig->rbfv[1]->invec,
379 tv->invec)] = tv;
380 break;
381 }
382 }
383 return((rbfv[0] != NULL) + (rbfv[1] != NULL));
384 }
385
386 /* Clear our BSDF representation and free memory */
387 void
388 clear_bsdf_rep(void)
389 {
390 while (mig_list != NULL) {
391 MIGRATION *mig = mig_list;
392 mig_list = mig->next;
393 free(mig);
394 }
395 while (dsf_list != NULL) {
396 RBFNODE *rbf = dsf_list;
397 dsf_list = rbf->next;
398 free(rbf);
399 }
400 inp_coverage = 0;
401 single_plane_incident = -1;
402 input_orient = output_orient = 0;
403 grid_res = GRIDRES;
404 }
405
406 /* Write our BSDF mesh interpolant out to the given binary stream */
407 void
408 save_bsdf_rep(FILE *ofp)
409 {
410 RBFNODE *rbf;
411 MIGRATION *mig;
412 int i, n;
413 /* finish header */
414 fprintf(ofp, "SYMMETRY=%d\n", !single_plane_incident * inp_coverage);
415 fprintf(ofp, "IO_SIDES= %d %d\n", input_orient, output_orient);
416 fprintf(ofp, "GRIDRES=%d\n", grid_res);
417 fprintf(ofp, "BSDFMIN=%g\n", bsdf_min);
418 fputformat(BSDFREP_FMT, ofp);
419 fputc('\n', ofp);
420 /* write each DSF */
421 for (rbf = dsf_list; rbf != NULL; rbf = rbf->next) {
422 putint(rbf->ord, 4, ofp);
423 putflt(rbf->invec[0], ofp);
424 putflt(rbf->invec[1], ofp);
425 putflt(rbf->invec[2], ofp);
426 putflt(rbf->vtotal, ofp);
427 putint(rbf->nrbf, 4, ofp);
428 for (i = 0; i < rbf->nrbf; i++) {
429 putflt(rbf->rbfa[i].peak, ofp);
430 putint(rbf->rbfa[i].crad, 2, ofp);
431 putint(rbf->rbfa[i].gx, 1, ofp);
432 putint(rbf->rbfa[i].gy, 1, ofp);
433 }
434 }
435 putint(-1, 4, ofp); /* terminator */
436 /* write each migration matrix */
437 for (mig = mig_list; mig != NULL; mig = mig->next) {
438 int zerocnt = 0;
439 putint(mig->rbfv[0]->ord, 4, ofp);
440 putint(mig->rbfv[1]->ord, 4, ofp);
441 /* write out as sparse data */
442 n = mtx_nrows(mig) * mtx_ncols(mig);
443 for (i = 0; i < n; i++) {
444 if (zerocnt == 0xff) {
445 putint(0xff, 1, ofp); zerocnt = 0;
446 }
447 if (mig->mtx[i] != 0) {
448 putint(zerocnt, 1, ofp); zerocnt = 0;
449 putflt(mig->mtx[i], ofp);
450 } else
451 ++zerocnt;
452 }
453 putint(zerocnt, 1, ofp);
454 }
455 putint(-1, 4, ofp); /* terminator */
456 putint(-1, 4, ofp);
457 if (fflush(ofp) == EOF) {
458 fprintf(stderr, "%s: error writing BSDF interpolant\n",
459 progname);
460 exit(1);
461 }
462 }
463
464 /* Check header line for critical information */
465 static int
466 headline(char *s, void *p)
467 {
468 char fmt[32];
469
470 if (!strncmp(s, "SYMMETRY=", 9)) {
471 inp_coverage = atoi(s+9);
472 single_plane_incident = !inp_coverage;
473 return(0);
474 }
475 if (!strncmp(s, "IO_SIDES=", 9)) {
476 sscanf(s+9, "%d %d", &input_orient, &output_orient);
477 return(0);
478 }
479 if (!strncmp(s, "GRIDRES=", 8)) {
480 sscanf(s+8, "%d", &grid_res);
481 return(0);
482 }
483 if (!strncmp(s, "BSDFMIN=", 8)) {
484 sscanf(s+8, "%lf", &bsdf_min);
485 return(0);
486 }
487 if (formatval(fmt, s) && strcmp(fmt, BSDFREP_FMT))
488 return(-1);
489 return(0);
490 }
491
492 /* Read a BSDF mesh interpolant from the given binary stream */
493 int
494 load_bsdf_rep(FILE *ifp)
495 {
496 RBFNODE rbfh;
497 int from_ord, to_ord;
498 int i;
499
500 clear_bsdf_rep();
501 if (ifp == NULL)
502 return(0);
503 if (getheader(ifp, headline, NULL) < 0 || single_plane_incident < 0 |
504 !input_orient | !output_orient) {
505 fprintf(stderr, "%s: missing/bad format for BSDF interpolant\n",
506 progname);
507 return(0);
508 }
509 rbfh.next = NULL; /* read each DSF */
510 rbfh.ejl = NULL;
511 while ((rbfh.ord = getint(4, ifp)) >= 0) {
512 RBFNODE *newrbf;
513
514 rbfh.invec[0] = getflt(ifp);
515 rbfh.invec[1] = getflt(ifp);
516 rbfh.invec[2] = getflt(ifp);
517 if (normalize(rbfh.invec) == 0) {
518 fprintf(stderr, "%s: zero incident vector\n", progname);
519 return(0);
520 }
521 rbfh.vtotal = getflt(ifp);
522 rbfh.nrbf = getint(4, ifp);
523 newrbf = (RBFNODE *)malloc(sizeof(RBFNODE) +
524 sizeof(RBFVAL)*(rbfh.nrbf-1));
525 if (newrbf == NULL)
526 goto memerr;
527 memcpy(newrbf, &rbfh, sizeof(RBFNODE)-sizeof(RBFVAL));
528 for (i = 0; i < rbfh.nrbf; i++) {
529 newrbf->rbfa[i].peak = getflt(ifp);
530 newrbf->rbfa[i].crad = getint(2, ifp) & 0xffff;
531 newrbf->rbfa[i].gx = getint(1, ifp) & 0xff;
532 newrbf->rbfa[i].gy = getint(1, ifp) & 0xff;
533 }
534 if (feof(ifp))
535 goto badEOF;
536 /* insert in global list */
537 if (insert_dsf(newrbf) != rbfh.ord) {
538 fprintf(stderr, "%s: error adding DSF\n", progname);
539 return(0);
540 }
541 }
542 /* read each migration matrix */
543 while ((from_ord = getint(4, ifp)) >= 0 &&
544 (to_ord = getint(4, ifp)) >= 0) {
545 RBFNODE *from_rbf = get_dsf(from_ord);
546 RBFNODE *to_rbf = get_dsf(to_ord);
547 MIGRATION *newmig;
548 int n;
549
550 if ((from_rbf == NULL) | (to_rbf == NULL)) {
551 fprintf(stderr,
552 "%s: bad DSF reference in migration edge\n",
553 progname);
554 return(0);
555 }
556 n = from_rbf->nrbf * to_rbf->nrbf;
557 newmig = (MIGRATION *)malloc(sizeof(MIGRATION) +
558 sizeof(float)*(n-1));
559 if (newmig == NULL)
560 goto memerr;
561 newmig->rbfv[0] = from_rbf;
562 newmig->rbfv[1] = to_rbf;
563 memset(newmig->mtx, 0, sizeof(float)*n);
564 for (i = 0; ; ) { /* read sparse data */
565 int zc = getint(1, ifp) & 0xff;
566 if ((i += zc) >= n)
567 break;
568 if (zc == 0xff)
569 continue;
570 newmig->mtx[i++] = getflt(ifp);
571 }
572 if (feof(ifp))
573 goto badEOF;
574 /* insert in edge lists */
575 newmig->enxt[0] = from_rbf->ejl;
576 from_rbf->ejl = newmig;
577 newmig->enxt[1] = to_rbf->ejl;
578 to_rbf->ejl = newmig;
579 /* push onto global list */
580 newmig->next = mig_list;
581 mig_list = newmig;
582 }
583 return(1); /* success! */
584 memerr:
585 fprintf(stderr, "%s: Out of memory in load_bsdf_rep()\n", progname);
586 exit(1);
587 badEOF:
588 fprintf(stderr, "%s: Unexpected EOF in load_bsdf_rep()\n", progname);
589 return(0);
590 }