ViewVC Help
View File | Revision Log | Show Annotations | Download File | Root Listing
root/radiance/ray/src/cv/bsdfrep.c
Revision: 2.19
Committed: Sat Nov 9 05:47:49 2013 UTC (10 years, 5 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.18: +18 -1 lines
Log Message:
Added tracking of BSDF sample name

File Contents

# Content
1 #ifndef lint
2 static const char RCSid[] = "$Id: bsdfrep.c,v 2.18 2013/11/08 05:37:20 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 /* name and manufacturer if known */
18 char bsdf_name[256];
19 char bsdf_manuf[256];
20 /* active grid resolution */
21 int grid_res = GRIDRES;
22
23 /* coverage/symmetry using INP_QUAD? flags */
24 int inp_coverage = 0;
25 /* all incident angles in-plane so far? */
26 int single_plane_incident = -1;
27
28 /* input/output orientations */
29 int input_orient = 0;
30 int output_orient = 0;
31
32 /* BSDF histogram */
33 unsigned long bsdf_hist[HISTLEN];
34
35 /* BSDF value for boundary regions */
36 double bsdf_min = 0;
37
38 /* processed incident DSF measurements */
39 RBFNODE *dsf_list = NULL;
40
41 /* RBF-linking matrices (edges) */
42 MIGRATION *mig_list = NULL;
43
44 /* current input direction */
45 double theta_in_deg, phi_in_deg;
46
47 /* Register new input direction */
48 int
49 new_input_direction(double new_theta, double new_phi)
50 {
51 if (!input_orient) /* check input orientation */
52 input_orient = 1 - 2*(new_theta > 90.);
53 else if (input_orient > 0 ^ new_theta < 90.) {
54 fprintf(stderr,
55 "%s: Cannot handle input angles on both sides of surface\n",
56 progname);
57 return(0);
58 }
59 /* normalize angle ranges */
60 while (new_theta < -180.)
61 new_theta += 360.;
62 while (new_theta > 180.)
63 new_theta -= 360.;
64 if (new_theta < 0) {
65 new_theta = -new_theta;
66 new_phi += 180.;
67 }
68 if ((theta_in_deg = new_theta) < 1.0)
69 return(1); /* don't rely on phi near normal */
70 while (new_phi < 0)
71 new_phi += 360.;
72 while (new_phi >= 360.)
73 new_phi -= 360.;
74 if (single_plane_incident > 0) /* check input coverage */
75 single_plane_incident = (round(new_phi) == round(phi_in_deg));
76 else if (single_plane_incident < 0)
77 single_plane_incident = 1;
78 phi_in_deg = new_phi;
79 if ((1. < new_phi) & (new_phi < 89.))
80 inp_coverage |= INP_QUAD1;
81 else if ((91. < new_phi) & (new_phi < 179.))
82 inp_coverage |= INP_QUAD2;
83 else if ((181. < new_phi) & (new_phi < 269.))
84 inp_coverage |= INP_QUAD3;
85 else if ((271. < new_phi) & (new_phi < 359.))
86 inp_coverage |= INP_QUAD4;
87 return(1);
88 }
89
90 /* Apply symmetry to the given vector based on distribution */
91 int
92 use_symmetry(FVECT vec)
93 {
94 const double phi = get_phi360(vec);
95
96 switch (inp_coverage) {
97 case INP_QUAD1|INP_QUAD2|INP_QUAD3|INP_QUAD4:
98 break;
99 case INP_QUAD1|INP_QUAD2:
100 if ((-FTINY > phi) | (phi > 180.+FTINY))
101 goto mir_y;
102 break;
103 case INP_QUAD2|INP_QUAD3:
104 if ((90.-FTINY > phi) | (phi > 270.+FTINY))
105 goto mir_x;
106 break;
107 case INP_QUAD3|INP_QUAD4:
108 if ((180.-FTINY > phi) | (phi > 360.+FTINY))
109 goto mir_y;
110 break;
111 case INP_QUAD4|INP_QUAD1:
112 if ((270.-FTINY > phi) & (phi > 90.+FTINY))
113 goto mir_x;
114 break;
115 case INP_QUAD1:
116 if ((-FTINY > phi) | (phi > 90.+FTINY))
117 switch ((int)(phi*(1./90.))) {
118 case 1: goto mir_x;
119 case 2: goto mir_xy;
120 case 3: goto mir_y;
121 }
122 break;
123 case INP_QUAD2:
124 if ((90.-FTINY > phi) | (phi > 180.+FTINY))
125 switch ((int)(phi*(1./90.))) {
126 case 0: goto mir_x;
127 case 2: goto mir_y;
128 case 3: goto mir_xy;
129 }
130 break;
131 case INP_QUAD3:
132 if ((180.-FTINY > phi) | (phi > 270.+FTINY))
133 switch ((int)(phi*(1./90.))) {
134 case 0: goto mir_xy;
135 case 1: goto mir_y;
136 case 3: goto mir_x;
137 }
138 break;
139 case INP_QUAD4:
140 if ((270.-FTINY > phi) | (phi > 360.+FTINY))
141 switch ((int)(phi*(1./90.))) {
142 case 0: goto mir_y;
143 case 1: goto mir_xy;
144 case 2: goto mir_x;
145 }
146 break;
147 default:
148 fprintf(stderr, "%s: Illegal input coverage (%d)\n",
149 progname, inp_coverage);
150 exit(1);
151 }
152 return(0); /* in range */
153 mir_x:
154 vec[0] = -vec[0];
155 return(MIRROR_X);
156 mir_y:
157 vec[1] = -vec[1];
158 return(MIRROR_Y);
159 mir_xy:
160 vec[0] = -vec[0];
161 vec[1] = -vec[1];
162 return(MIRROR_X|MIRROR_Y);
163 }
164
165 /* Reverse symmetry based on what was done before */
166 void
167 rev_symmetry(FVECT vec, int sym)
168 {
169 if (sym & MIRROR_X)
170 vec[0] = -vec[0];
171 if (sym & MIRROR_Y)
172 vec[1] = -vec[1];
173 }
174
175 /* Reverse symmetry for an RBF distribution */
176 void
177 rev_rbf_symmetry(RBFNODE *rbf, int sym)
178 {
179 int n;
180
181 rev_symmetry(rbf->invec, sym);
182 if (sym & MIRROR_X)
183 for (n = rbf->nrbf; n-- > 0; )
184 rbf->rbfa[n].gx = grid_res-1 - rbf->rbfa[n].gx;
185 if (sym & MIRROR_Y)
186 for (n = rbf->nrbf; n-- > 0; )
187 rbf->rbfa[n].gy = grid_res-1 - rbf->rbfa[n].gy;
188 }
189
190 /* Rotate RBF to correspond to given incident vector */
191 void
192 rotate_rbf(RBFNODE *rbf, const FVECT invec)
193 {
194 static const FVECT vnorm = {.0, .0, 1.};
195 const double phi = atan2(invec[1],invec[0]) -
196 atan2(rbf->invec[1],rbf->invec[0]);
197 FVECT outvec;
198 int pos[2];
199 int n;
200
201 for (n = ((-.01 > phi) | (phi > .01))*rbf->nrbf; n-- > 0; ) {
202 ovec_from_pos(outvec, rbf->rbfa[n].gx, rbf->rbfa[n].gy);
203 spinvector(outvec, outvec, vnorm, phi);
204 pos_from_vec(pos, outvec);
205 rbf->rbfa[n].gx = pos[0];
206 rbf->rbfa[n].gy = pos[1];
207 }
208 VCOPY(rbf->invec, invec);
209 }
210
211 /* Compute outgoing vector from grid position */
212 void
213 ovec_from_pos(FVECT vec, int xpos, int ypos)
214 {
215 double uv[2];
216 double r2;
217
218 SDsquare2disk(uv, (xpos+.5)/grid_res, (ypos+.5)/grid_res);
219 /* uniform hemispherical projection */
220 r2 = uv[0]*uv[0] + uv[1]*uv[1];
221 vec[0] = vec[1] = sqrt(2. - r2);
222 vec[0] *= uv[0];
223 vec[1] *= uv[1];
224 vec[2] = output_orient*(1. - r2);
225 }
226
227 /* Compute grid position from normalized input/output vector */
228 void
229 pos_from_vec(int pos[2], const FVECT vec)
230 {
231 double sq[2]; /* uniform hemispherical projection */
232 double norm = 1./sqrt(1. + fabs(vec[2]));
233
234 SDdisk2square(sq, vec[0]*norm, vec[1]*norm);
235
236 pos[0] = (int)(sq[0]*grid_res);
237 pos[1] = (int)(sq[1]*grid_res);
238 }
239
240 /* Compute volume associated with Gaussian lobe */
241 double
242 rbf_volume(const RBFVAL *rbfp)
243 {
244 double rad = R2ANG(rbfp->crad);
245 FVECT odir;
246 double elev, integ;
247 /* infinite integral approximation */
248 integ = (2.*M_PI) * rbfp->peak * rad*rad;
249 /* check if we're near horizon */
250 ovec_from_pos(odir, rbfp->gx, rbfp->gy);
251 elev = output_orient*odir[2];
252 /* apply cut-off correction if > 1% */
253 if (elev < 2.8*rad) {
254 /* elev = asin(elev); /* this is so crude, anyway... */
255 integ *= 1. - .5*exp(-.5*elev*elev/(rad*rad));
256 }
257 return(integ);
258 }
259
260 /* Evaluate RBF for DSF at the given normalized outgoing direction */
261 double
262 eval_rbfrep(const RBFNODE *rp, const FVECT outvec)
263 {
264 const double rfact2 = (38./M_PI/M_PI)*(grid_res*grid_res);
265 double minval = bsdf_min*output_orient*outvec[2];
266 int pos[2];
267 double res = 0;
268 const RBFVAL *rbfp;
269 FVECT odir;
270 double rad2;
271 int n;
272 /* check for wrong side */
273 if (outvec[2] > 0 ^ output_orient > 0)
274 return(.0);
275 /* use minimum if no information avail. */
276 if (rp == NULL)
277 return(minval);
278 /* optimization for fast lobe culling */
279 pos_from_vec(pos, outvec);
280 /* sum radial basis function */
281 rbfp = rp->rbfa;
282 for (n = rp->nrbf; n--; rbfp++) {
283 int d2 = (pos[0]-rbfp->gx)*(pos[0]-rbfp->gx) +
284 (pos[1]-rbfp->gy)*(pos[1]-rbfp->gy);
285 rad2 = R2ANG(rbfp->crad);
286 rad2 *= rad2;
287 if (d2 > rad2*rfact2)
288 continue;
289 ovec_from_pos(odir, rbfp->gx, rbfp->gy);
290 res += rbfp->peak * exp((DOT(odir,outvec) - 1.) / rad2);
291 }
292 if (res < minval) /* never return less than minval */
293 return(minval);
294 return(res);
295 }
296
297 /* Insert a new directional scattering function in our global list */
298 int
299 insert_dsf(RBFNODE *newrbf)
300 {
301 RBFNODE *rbf, *rbf_last;
302 int pos;
303 /* check for redundant meas. */
304 for (rbf = dsf_list; rbf != NULL; rbf = rbf->next)
305 if (DOT(rbf->invec, newrbf->invec) >= 1.-FTINY) {
306 fprintf(stderr,
307 "%s: Duplicate incident measurement (ignored)\n",
308 progname);
309 free(newrbf);
310 return(-1);
311 }
312 /* keep in ascending theta order */
313 for (rbf_last = NULL, rbf = dsf_list; rbf != NULL;
314 rbf_last = rbf, rbf = rbf->next)
315 if (single_plane_incident && input_orient*rbf->invec[2] <
316 input_orient*newrbf->invec[2])
317 break;
318 if (rbf_last == NULL) { /* insert new node in list */
319 newrbf->ord = 0;
320 newrbf->next = dsf_list;
321 dsf_list = newrbf;
322 } else {
323 newrbf->ord = rbf_last->ord + 1;
324 newrbf->next = rbf;
325 rbf_last->next = newrbf;
326 }
327 rbf_last = newrbf;
328 while (rbf != NULL) { /* update ordinal positions */
329 rbf->ord = rbf_last->ord + 1;
330 rbf_last = rbf;
331 rbf = rbf->next;
332 }
333 return(newrbf->ord);
334 }
335
336 /* Get the DSF indicated by its ordinal position */
337 RBFNODE *
338 get_dsf(int ord)
339 {
340 RBFNODE *rbf;
341
342 for (rbf = dsf_list; rbf != NULL; rbf = rbf->next)
343 if (rbf->ord == ord)
344 return(rbf);
345 return(NULL);
346 }
347
348 /* Get triangle surface orientation (unnormalized) */
349 void
350 tri_orient(FVECT vres, const FVECT v1, const FVECT v2, const FVECT v3)
351 {
352 FVECT v2minus1, v3minus2;
353
354 VSUB(v2minus1, v2, v1);
355 VSUB(v3minus2, v3, v2);
356 VCROSS(vres, v2minus1, v3minus2);
357 }
358
359 /* Determine if vertex order is reversed (inward normal) */
360 int
361 is_rev_tri(const FVECT v1, const FVECT v2, const FVECT v3)
362 {
363 FVECT tor;
364
365 tri_orient(tor, v1, v2, v3);
366
367 return(DOT(tor, v2) < 0.);
368 }
369
370 /* Find vertices completing triangles on either side of the given edge */
371 int
372 get_triangles(RBFNODE *rbfv[2], const MIGRATION *mig)
373 {
374 const MIGRATION *ej1, *ej2;
375 RBFNODE *tv;
376
377 rbfv[0] = rbfv[1] = NULL;
378 if (mig == NULL)
379 return(0);
380 for (ej1 = mig->rbfv[0]->ejl; ej1 != NULL;
381 ej1 = nextedge(mig->rbfv[0],ej1)) {
382 if (ej1 == mig)
383 continue;
384 tv = opp_rbf(mig->rbfv[0],ej1);
385 for (ej2 = tv->ejl; ej2 != NULL; ej2 = nextedge(tv,ej2))
386 if (opp_rbf(tv,ej2) == mig->rbfv[1]) {
387 rbfv[is_rev_tri(mig->rbfv[0]->invec,
388 mig->rbfv[1]->invec,
389 tv->invec)] = tv;
390 break;
391 }
392 }
393 return((rbfv[0] != NULL) + (rbfv[1] != NULL));
394 }
395
396 /* Clear our BSDF representation and free memory */
397 void
398 clear_bsdf_rep(void)
399 {
400 while (mig_list != NULL) {
401 MIGRATION *mig = mig_list;
402 mig_list = mig->next;
403 free(mig);
404 }
405 while (dsf_list != NULL) {
406 RBFNODE *rbf = dsf_list;
407 dsf_list = rbf->next;
408 free(rbf);
409 }
410 bsdf_name[0] = '\0';
411 bsdf_manuf[0] = '\0';
412 inp_coverage = 0;
413 single_plane_incident = -1;
414 input_orient = output_orient = 0;
415 grid_res = GRIDRES;
416 }
417
418 /* Write our BSDF mesh interpolant out to the given binary stream */
419 void
420 save_bsdf_rep(FILE *ofp)
421 {
422 RBFNODE *rbf;
423 MIGRATION *mig;
424 int i, n;
425 /* finish header */
426 if (bsdf_name[0])
427 fprintf(ofp, "NAME=%s\n", bsdf_name);
428 if (bsdf_manuf[0])
429 fprintf(ofp, "MANUFACT=%s\n", bsdf_manuf);
430 fprintf(ofp, "SYMMETRY=%d\n", !single_plane_incident * inp_coverage);
431 fprintf(ofp, "IO_SIDES= %d %d\n", input_orient, output_orient);
432 fprintf(ofp, "GRIDRES=%d\n", grid_res);
433 fprintf(ofp, "BSDFMIN=%g\n", bsdf_min);
434 fputformat(BSDFREP_FMT, ofp);
435 fputc('\n', ofp);
436 /* write each DSF */
437 for (rbf = dsf_list; rbf != NULL; rbf = rbf->next) {
438 putint(rbf->ord, 4, ofp);
439 putflt(rbf->invec[0], ofp);
440 putflt(rbf->invec[1], ofp);
441 putflt(rbf->invec[2], ofp);
442 putflt(rbf->vtotal, ofp);
443 putint(rbf->nrbf, 4, ofp);
444 for (i = 0; i < rbf->nrbf; i++) {
445 putflt(rbf->rbfa[i].peak, ofp);
446 putint(rbf->rbfa[i].crad, 2, ofp);
447 putint(rbf->rbfa[i].gx, 1, ofp);
448 putint(rbf->rbfa[i].gy, 1, ofp);
449 }
450 }
451 putint(-1, 4, ofp); /* terminator */
452 /* write each migration matrix */
453 for (mig = mig_list; mig != NULL; mig = mig->next) {
454 int zerocnt = 0;
455 putint(mig->rbfv[0]->ord, 4, ofp);
456 putint(mig->rbfv[1]->ord, 4, ofp);
457 /* write out as sparse data */
458 n = mtx_nrows(mig) * mtx_ncols(mig);
459 for (i = 0; i < n; i++) {
460 if (zerocnt == 0xff) {
461 putint(0xff, 1, ofp); zerocnt = 0;
462 }
463 if (mig->mtx[i] != 0) {
464 putint(zerocnt, 1, ofp); zerocnt = 0;
465 putflt(mig->mtx[i], ofp);
466 } else
467 ++zerocnt;
468 }
469 putint(zerocnt, 1, ofp);
470 }
471 putint(-1, 4, ofp); /* terminator */
472 putint(-1, 4, ofp);
473 if (fflush(ofp) == EOF) {
474 fprintf(stderr, "%s: error writing BSDF interpolant\n",
475 progname);
476 exit(1);
477 }
478 }
479
480 /* Check header line for critical information */
481 static int
482 headline(char *s, void *p)
483 {
484 char fmt[32];
485
486 if (!strncmp(s, "NAME=", 5)) {
487 strcpy(bsdf_name, s+5);
488 bsdf_name[strlen(bsdf_name)-1] = '\0';
489 }
490 if (!strncmp(s, "MANUFACT=", 9)) {
491 strcpy(bsdf_manuf, s+9);
492 bsdf_manuf[strlen(bsdf_manuf)-1] = '\0';
493 }
494 if (!strncmp(s, "SYMMETRY=", 9)) {
495 inp_coverage = atoi(s+9);
496 single_plane_incident = !inp_coverage;
497 return(0);
498 }
499 if (!strncmp(s, "IO_SIDES=", 9)) {
500 sscanf(s+9, "%d %d", &input_orient, &output_orient);
501 return(0);
502 }
503 if (!strncmp(s, "GRIDRES=", 8)) {
504 sscanf(s+8, "%d", &grid_res);
505 return(0);
506 }
507 if (!strncmp(s, "BSDFMIN=", 8)) {
508 sscanf(s+8, "%lf", &bsdf_min);
509 return(0);
510 }
511 if (formatval(fmt, s) && strcmp(fmt, BSDFREP_FMT))
512 return(-1);
513 return(0);
514 }
515
516 /* Read a BSDF mesh interpolant from the given binary stream */
517 int
518 load_bsdf_rep(FILE *ifp)
519 {
520 RBFNODE rbfh;
521 int from_ord, to_ord;
522 int i;
523
524 clear_bsdf_rep();
525 if (ifp == NULL)
526 return(0);
527 if (getheader(ifp, headline, NULL) < 0 || single_plane_incident < 0 |
528 !input_orient | !output_orient) {
529 fprintf(stderr, "%s: missing/bad format for BSDF interpolant\n",
530 progname);
531 return(0);
532 }
533 memset(&rbfh, 0, sizeof(rbfh)); /* read each DSF */
534 while ((rbfh.ord = getint(4, ifp)) >= 0) {
535 RBFNODE *newrbf;
536
537 rbfh.invec[0] = getflt(ifp);
538 rbfh.invec[1] = getflt(ifp);
539 rbfh.invec[2] = getflt(ifp);
540 if (normalize(rbfh.invec) == 0) {
541 fprintf(stderr, "%s: zero incident vector\n", progname);
542 return(0);
543 }
544 rbfh.vtotal = getflt(ifp);
545 rbfh.nrbf = getint(4, ifp);
546 newrbf = (RBFNODE *)malloc(sizeof(RBFNODE) +
547 sizeof(RBFVAL)*(rbfh.nrbf-1));
548 if (newrbf == NULL)
549 goto memerr;
550 *newrbf = rbfh;
551 for (i = 0; i < rbfh.nrbf; i++) {
552 newrbf->rbfa[i].peak = getflt(ifp);
553 newrbf->rbfa[i].crad = getint(2, ifp) & 0xffff;
554 newrbf->rbfa[i].gx = getint(1, ifp) & 0xff;
555 newrbf->rbfa[i].gy = getint(1, ifp) & 0xff;
556 }
557 if (feof(ifp))
558 goto badEOF;
559 /* insert in global list */
560 if (insert_dsf(newrbf) != rbfh.ord) {
561 fprintf(stderr, "%s: error adding DSF\n", progname);
562 return(0);
563 }
564 }
565 /* read each migration matrix */
566 while ((from_ord = getint(4, ifp)) >= 0 &&
567 (to_ord = getint(4, ifp)) >= 0) {
568 RBFNODE *from_rbf = get_dsf(from_ord);
569 RBFNODE *to_rbf = get_dsf(to_ord);
570 MIGRATION *newmig;
571 int n;
572
573 if ((from_rbf == NULL) | (to_rbf == NULL)) {
574 fprintf(stderr,
575 "%s: bad DSF reference in migration edge\n",
576 progname);
577 return(0);
578 }
579 n = from_rbf->nrbf * to_rbf->nrbf;
580 newmig = (MIGRATION *)malloc(sizeof(MIGRATION) +
581 sizeof(float)*(n-1));
582 if (newmig == NULL)
583 goto memerr;
584 newmig->rbfv[0] = from_rbf;
585 newmig->rbfv[1] = to_rbf;
586 memset(newmig->mtx, 0, sizeof(float)*n);
587 for (i = 0; ; ) { /* read sparse data */
588 int zc = getint(1, ifp) & 0xff;
589 if ((i += zc) >= n)
590 break;
591 if (zc == 0xff)
592 continue;
593 newmig->mtx[i++] = getflt(ifp);
594 }
595 if (feof(ifp))
596 goto badEOF;
597 /* insert in edge lists */
598 newmig->enxt[0] = from_rbf->ejl;
599 from_rbf->ejl = newmig;
600 newmig->enxt[1] = to_rbf->ejl;
601 to_rbf->ejl = newmig;
602 /* push onto global list */
603 newmig->next = mig_list;
604 mig_list = newmig;
605 }
606 return(1); /* success! */
607 memerr:
608 fprintf(stderr, "%s: Out of memory in load_bsdf_rep()\n", progname);
609 exit(1);
610 badEOF:
611 fprintf(stderr, "%s: Unexpected EOF in load_bsdf_rep()\n", progname);
612 return(0);
613 }