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root/radiance/ray/src/cv/bsdfrep.c
Revision: 2.11
Committed: Thu Nov 22 06:07:17 2012 UTC (11 years, 5 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.10: +2 -2 lines
Log Message:
Bug fix in geodesic() and other minor improvements

File Contents

# Content
1 #ifndef lint
2 static const char RCSid[] = "$Id: bsdfrep.c,v 2.10 2012/11/18 03:56:39 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 /* processed incident DSF measurements */
30 RBFNODE *dsf_list = NULL;
31
32 /* RBF-linking matrices (edges) */
33 MIGRATION *mig_list = NULL;
34
35 /* current input direction */
36 double theta_in_deg, phi_in_deg;
37
38 /* Register new input direction */
39 int
40 new_input_direction(double new_theta, double new_phi)
41 {
42 if (!input_orient) /* check input orientation */
43 input_orient = 1 - 2*(new_theta > 90.);
44 else if (input_orient > 0 ^ new_theta < 90.) {
45 fprintf(stderr,
46 "%s: Cannot handle input angles on both sides of surface\n",
47 progname);
48 return(0);
49 }
50 /* normalize angle ranges */
51 while (new_theta < -180.)
52 new_theta += 360.;
53 while (new_theta > 180.)
54 new_theta -= 360.;
55 if (new_theta < 0) {
56 new_theta = -new_theta;
57 new_phi += 180.;
58 }
59 if ((theta_in_deg = new_theta) < 1.0)
60 return(1); /* don't rely on phi near normal */
61 while (new_phi < 0)
62 new_phi += 360.;
63 while (new_phi >= 360.)
64 new_phi -= 360.;
65 if (single_plane_incident > 0) /* check input coverage */
66 single_plane_incident = (round(new_phi) == round(phi_in_deg));
67 else if (single_plane_incident < 0)
68 single_plane_incident = 1;
69 phi_in_deg = new_phi;
70 if ((1. < new_phi) & (new_phi < 89.))
71 inp_coverage |= INP_QUAD1;
72 else if ((91. < new_phi) & (new_phi < 179.))
73 inp_coverage |= INP_QUAD2;
74 else if ((181. < new_phi) & (new_phi < 269.))
75 inp_coverage |= INP_QUAD3;
76 else if ((271. < new_phi) & (new_phi < 359.))
77 inp_coverage |= INP_QUAD4;
78 return(1);
79 }
80
81 /* Apply symmetry to the given vector based on distribution */
82 int
83 use_symmetry(FVECT vec)
84 {
85 const double phi = get_phi360(vec);
86
87 switch (inp_coverage) {
88 case INP_QUAD1|INP_QUAD2|INP_QUAD3|INP_QUAD4:
89 break;
90 case INP_QUAD1|INP_QUAD2:
91 if ((-FTINY > phi) | (phi > 180.+FTINY))
92 goto mir_y;
93 break;
94 case INP_QUAD2|INP_QUAD3:
95 if ((90.-FTINY > phi) | (phi > 270.+FTINY))
96 goto mir_x;
97 break;
98 case INP_QUAD3|INP_QUAD4:
99 if ((180.-FTINY > phi) | (phi > 360.+FTINY))
100 goto mir_y;
101 break;
102 case INP_QUAD4|INP_QUAD1:
103 if ((270.-FTINY > phi) & (phi > 90.+FTINY))
104 goto mir_x;
105 break;
106 case INP_QUAD1:
107 if ((-FTINY > phi) | (phi > 90.+FTINY))
108 switch ((int)(phi*(1./90.))) {
109 case 1: goto mir_x;
110 case 2: goto mir_xy;
111 case 3: goto mir_y;
112 }
113 break;
114 case INP_QUAD2:
115 if ((90.-FTINY > phi) | (phi > 180.+FTINY))
116 switch ((int)(phi*(1./90.))) {
117 case 0: goto mir_x;
118 case 2: goto mir_y;
119 case 3: goto mir_xy;
120 }
121 break;
122 case INP_QUAD3:
123 if ((180.-FTINY > phi) | (phi > 270.+FTINY))
124 switch ((int)(phi*(1./90.))) {
125 case 0: goto mir_xy;
126 case 1: goto mir_y;
127 case 3: goto mir_x;
128 }
129 break;
130 case INP_QUAD4:
131 if ((270.-FTINY > phi) | (phi > 360.+FTINY))
132 switch ((int)(phi*(1./90.))) {
133 case 0: goto mir_y;
134 case 1: goto mir_xy;
135 case 2: goto mir_x;
136 }
137 break;
138 default:
139 fprintf(stderr, "%s: Illegal input coverage (%d)\n",
140 progname, inp_coverage);
141 exit(1);
142 }
143 return(0); /* in range */
144 mir_x:
145 vec[0] = -vec[0];
146 return(MIRROR_X);
147 mir_y:
148 vec[1] = -vec[1];
149 return(MIRROR_Y);
150 mir_xy:
151 vec[0] = -vec[0];
152 vec[1] = -vec[1];
153 return(MIRROR_X|MIRROR_Y);
154 }
155
156 /* Reverse symmetry based on what was done before */
157 void
158 rev_symmetry(FVECT vec, int sym)
159 {
160 if (sym & MIRROR_X)
161 vec[0] = -vec[0];
162 if (sym & MIRROR_Y)
163 vec[1] = -vec[1];
164 }
165
166 /* Reverse symmetry for an RBF distribution */
167 void
168 rev_rbf_symmetry(RBFNODE *rbf, int sym)
169 {
170 int n;
171
172 rev_symmetry(rbf->invec, sym);
173 if (sym & MIRROR_X)
174 for (n = rbf->nrbf; n-- > 0; )
175 rbf->rbfa[n].gx = grid_res-1 - rbf->rbfa[n].gx;
176 if (sym & MIRROR_Y)
177 for (n = rbf->nrbf; n-- > 0; )
178 rbf->rbfa[n].gy = grid_res-1 - rbf->rbfa[n].gy;
179 }
180
181 /* Rotate RBF to correspond to given incident vector */
182 void
183 rotate_rbf(RBFNODE *rbf, const FVECT invec)
184 {
185 static const FVECT vnorm = {.0, .0, 1.};
186 const double phi = atan2(invec[1],invec[0]) -
187 atan2(rbf->invec[1],rbf->invec[0]);
188 FVECT outvec;
189 int pos[2];
190 int n;
191
192 for (n = ((-.01 > phi) | (phi > .01))*rbf->nrbf; n-- > 0; ) {
193 ovec_from_pos(outvec, rbf->rbfa[n].gx, rbf->rbfa[n].gy);
194 spinvector(outvec, outvec, vnorm, phi);
195 pos_from_vec(pos, outvec);
196 rbf->rbfa[n].gx = pos[0];
197 rbf->rbfa[n].gy = pos[1];
198 }
199 VCOPY(rbf->invec, invec);
200 }
201
202 /* Compute volume associated with Gaussian lobe */
203 double
204 rbf_volume(const RBFVAL *rbfp)
205 {
206 double rad = R2ANG(rbfp->crad);
207
208 return((2.*M_PI) * rbfp->peak * rad*rad);
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 /* Evaluate RBF for DSF at the given normalized outgoing direction */
241 double
242 eval_rbfrep(const RBFNODE *rp, const FVECT outvec)
243 {
244 double res = 0;
245 const RBFVAL *rbfp;
246 FVECT odir;
247 double sig2;
248 int n;
249
250 if (rp == NULL)
251 return(.0);
252 rbfp = rp->rbfa;
253 for (n = rp->nrbf; n--; rbfp++) {
254 ovec_from_pos(odir, rbfp->gx, rbfp->gy);
255 sig2 = R2ANG(rbfp->crad);
256 sig2 = (DOT(odir,outvec) - 1.) / (sig2*sig2);
257 if (sig2 > -19.)
258 res += rbfp->peak * exp(sig2);
259 }
260 return(res);
261 }
262
263 /* Insert a new directional scattering function in our global list */
264 int
265 insert_dsf(RBFNODE *newrbf)
266 {
267 RBFNODE *rbf, *rbf_last;
268 int pos;
269 /* check for redundant meas. */
270 for (rbf = dsf_list; rbf != NULL; rbf = rbf->next)
271 if (DOT(rbf->invec, newrbf->invec) >= 1.-FTINY) {
272 fprintf(stderr,
273 "%s: Duplicate incident measurement (ignored)\n",
274 progname);
275 free(newrbf);
276 return(-1);
277 }
278 /* keep in ascending theta order */
279 for (rbf_last = NULL, rbf = dsf_list; rbf != NULL;
280 rbf_last = rbf, rbf = rbf->next)
281 if (single_plane_incident && input_orient*rbf->invec[2] <
282 input_orient*newrbf->invec[2])
283 break;
284 if (rbf_last == NULL) { /* insert new node in list */
285 newrbf->ord = 0;
286 newrbf->next = dsf_list;
287 dsf_list = newrbf;
288 } else {
289 newrbf->ord = rbf_last->ord + 1;
290 newrbf->next = rbf;
291 rbf_last->next = newrbf;
292 }
293 rbf_last = newrbf;
294 while (rbf != NULL) { /* update ordinal positions */
295 rbf->ord = rbf_last->ord + 1;
296 rbf_last = rbf;
297 rbf = rbf->next;
298 }
299 return(newrbf->ord);
300 }
301
302 /* Get the DSF indicated by its ordinal position */
303 RBFNODE *
304 get_dsf(int ord)
305 {
306 RBFNODE *rbf;
307
308 for (rbf = dsf_list; rbf != NULL; rbf = rbf->next)
309 if (rbf->ord == ord)
310 return(rbf);
311 return(NULL);
312 }
313
314 /* Get triangle surface orientation (unnormalized) */
315 void
316 tri_orient(FVECT vres, const FVECT v1, const FVECT v2, const FVECT v3)
317 {
318 FVECT v2minus1, v3minus2;
319
320 VSUB(v2minus1, v2, v1);
321 VSUB(v3minus2, v3, v2);
322 VCROSS(vres, v2minus1, v3minus2);
323 }
324
325 /* Determine if vertex order is reversed (inward normal) */
326 int
327 is_rev_tri(const FVECT v1, const FVECT v2, const FVECT v3)
328 {
329 FVECT tor;
330
331 tri_orient(tor, v1, v2, v3);
332
333 return(DOT(tor, v2) < 0.);
334 }
335
336 /* Find vertices completing triangles on either side of the given edge */
337 int
338 get_triangles(RBFNODE *rbfv[2], const MIGRATION *mig)
339 {
340 const MIGRATION *ej1, *ej2;
341 RBFNODE *tv;
342
343 rbfv[0] = rbfv[1] = NULL;
344 if (mig == NULL)
345 return(0);
346 for (ej1 = mig->rbfv[0]->ejl; ej1 != NULL;
347 ej1 = nextedge(mig->rbfv[0],ej1)) {
348 if (ej1 == mig)
349 continue;
350 tv = opp_rbf(mig->rbfv[0],ej1);
351 for (ej2 = tv->ejl; ej2 != NULL; ej2 = nextedge(tv,ej2))
352 if (opp_rbf(tv,ej2) == mig->rbfv[1]) {
353 rbfv[is_rev_tri(mig->rbfv[0]->invec,
354 mig->rbfv[1]->invec,
355 tv->invec)] = tv;
356 break;
357 }
358 }
359 return((rbfv[0] != NULL) + (rbfv[1] != NULL));
360 }
361
362 /* Clear our BSDF representation and free memory */
363 void
364 clear_bsdf_rep(void)
365 {
366 while (mig_list != NULL) {
367 MIGRATION *mig = mig_list;
368 mig_list = mig->next;
369 free(mig);
370 }
371 while (dsf_list != NULL) {
372 RBFNODE *rbf = dsf_list;
373 dsf_list = rbf->next;
374 free(rbf);
375 }
376 inp_coverage = 0;
377 single_plane_incident = -1;
378 input_orient = output_orient = 0;
379 grid_res = GRIDRES;
380 }
381
382 /* Write our BSDF mesh interpolant out to the given binary stream */
383 void
384 save_bsdf_rep(FILE *ofp)
385 {
386 RBFNODE *rbf;
387 MIGRATION *mig;
388 int i, n;
389 /* finish header */
390 fprintf(ofp, "SYMMETRY=%d\n", !single_plane_incident * inp_coverage);
391 fprintf(ofp, "IO_SIDES= %d %d\n", input_orient, output_orient);
392 fprintf(ofp, "GRIDRES=%d\n", grid_res);
393 fputformat(BSDFREP_FMT, ofp);
394 fputc('\n', ofp);
395 /* write each DSF */
396 for (rbf = dsf_list; rbf != NULL; rbf = rbf->next) {
397 putint(rbf->ord, 4, ofp);
398 putflt(rbf->invec[0], ofp);
399 putflt(rbf->invec[1], ofp);
400 putflt(rbf->invec[2], ofp);
401 putflt(rbf->vtotal, ofp);
402 putint(rbf->nrbf, 4, ofp);
403 for (i = 0; i < rbf->nrbf; i++) {
404 putflt(rbf->rbfa[i].peak, ofp);
405 putint(rbf->rbfa[i].crad, 2, ofp);
406 putint(rbf->rbfa[i].gx, 1, ofp);
407 putint(rbf->rbfa[i].gy, 1, ofp);
408 }
409 }
410 putint(-1, 4, ofp); /* terminator */
411 /* write each migration matrix */
412 for (mig = mig_list; mig != NULL; mig = mig->next) {
413 int zerocnt = 0;
414 putint(mig->rbfv[0]->ord, 4, ofp);
415 putint(mig->rbfv[1]->ord, 4, ofp);
416 /* write out as sparse data */
417 n = mtx_nrows(mig) * mtx_ncols(mig);
418 for (i = 0; i < n; i++) {
419 if (zerocnt == 0xff) {
420 putint(0xff, 1, ofp); zerocnt = 0;
421 }
422 if (mig->mtx[i] != 0) {
423 putint(zerocnt, 1, ofp); zerocnt = 0;
424 putflt(mig->mtx[i], ofp);
425 } else
426 ++zerocnt;
427 }
428 putint(zerocnt, 1, ofp);
429 }
430 putint(-1, 4, ofp); /* terminator */
431 putint(-1, 4, ofp);
432 if (fflush(ofp) == EOF) {
433 fprintf(stderr, "%s: error writing BSDF interpolant\n",
434 progname);
435 exit(1);
436 }
437 }
438
439 /* Check header line for critical information */
440 static int
441 headline(char *s, void *p)
442 {
443 char fmt[32];
444
445 if (!strncmp(s, "SYMMETRY=", 9)) {
446 inp_coverage = atoi(s+9);
447 single_plane_incident = !inp_coverage;
448 return(0);
449 }
450 if (!strncmp(s, "IO_SIDES=", 9)) {
451 sscanf(s+9, "%d %d", &input_orient, &output_orient);
452 return(0);
453 }
454 if (!strncmp(s, "GRIDRES=", 8)) {
455 sscanf(s+8, "%d", &grid_res);
456 return(0);
457 }
458 if (formatval(fmt, s) && strcmp(fmt, BSDFREP_FMT))
459 return(-1);
460 return(0);
461 }
462
463 /* Read a BSDF mesh interpolant from the given binary stream */
464 int
465 load_bsdf_rep(FILE *ifp)
466 {
467 RBFNODE rbfh;
468 int from_ord, to_ord;
469 int i;
470
471 clear_bsdf_rep();
472 if (ifp == NULL)
473 return(0);
474 if (getheader(ifp, headline, NULL) < 0 || single_plane_incident < 0 |
475 !input_orient | !output_orient) {
476 fprintf(stderr, "%s: missing/bad format for BSDF interpolant\n",
477 progname);
478 return(0);
479 }
480 rbfh.next = NULL; /* read each DSF */
481 rbfh.ejl = NULL;
482 while ((rbfh.ord = getint(4, ifp)) >= 0) {
483 RBFNODE *newrbf;
484
485 rbfh.invec[0] = getflt(ifp);
486 rbfh.invec[1] = getflt(ifp);
487 rbfh.invec[2] = getflt(ifp);
488 if (normalize(rbfh.invec) == 0) {
489 fprintf(stderr, "%s: zero incident vector\n", progname);
490 return(0);
491 }
492 rbfh.vtotal = getflt(ifp);
493 rbfh.nrbf = getint(4, ifp);
494 newrbf = (RBFNODE *)malloc(sizeof(RBFNODE) +
495 sizeof(RBFVAL)*(rbfh.nrbf-1));
496 if (newrbf == NULL)
497 goto memerr;
498 memcpy(newrbf, &rbfh, sizeof(RBFNODE)-sizeof(RBFVAL));
499 for (i = 0; i < rbfh.nrbf; i++) {
500 newrbf->rbfa[i].peak = getflt(ifp);
501 newrbf->rbfa[i].crad = getint(2, ifp) & 0xffff;
502 newrbf->rbfa[i].gx = getint(1, ifp) & 0xff;
503 newrbf->rbfa[i].gy = getint(1, ifp) & 0xff;
504 }
505 if (feof(ifp))
506 goto badEOF;
507 /* insert in global list */
508 if (insert_dsf(newrbf) != rbfh.ord) {
509 fprintf(stderr, "%s: error adding DSF\n", progname);
510 return(0);
511 }
512 }
513 /* read each migration matrix */
514 while ((from_ord = getint(4, ifp)) >= 0 &&
515 (to_ord = getint(4, ifp)) >= 0) {
516 RBFNODE *from_rbf = get_dsf(from_ord);
517 RBFNODE *to_rbf = get_dsf(to_ord);
518 MIGRATION *newmig;
519 int n;
520
521 if ((from_rbf == NULL) | (to_rbf == NULL)) {
522 fprintf(stderr,
523 "%s: bad DSF reference in migration edge\n",
524 progname);
525 return(0);
526 }
527 n = from_rbf->nrbf * to_rbf->nrbf;
528 newmig = (MIGRATION *)malloc(sizeof(MIGRATION) +
529 sizeof(float)*(n-1));
530 if (newmig == NULL)
531 goto memerr;
532 newmig->rbfv[0] = from_rbf;
533 newmig->rbfv[1] = to_rbf;
534 memset(newmig->mtx, 0, sizeof(float)*n);
535 for (i = 0; ; ) { /* read sparse data */
536 int zc = getint(1, ifp) & 0xff;
537 if ((i += zc) >= n)
538 break;
539 if (zc == 0xff)
540 continue;
541 newmig->mtx[i++] = getflt(ifp);
542 }
543 if (feof(ifp))
544 goto badEOF;
545 /* insert in edge lists */
546 newmig->enxt[0] = from_rbf->ejl;
547 from_rbf->ejl = newmig;
548 newmig->enxt[1] = to_rbf->ejl;
549 to_rbf->ejl = newmig;
550 /* push onto global list */
551 newmig->next = mig_list;
552 mig_list = newmig;
553 }
554 return(1); /* success! */
555 memerr:
556 fprintf(stderr, "%s: Out of memory in load_bsdf_rep()\n", progname);
557 exit(1);
558 badEOF:
559 fprintf(stderr, "%s: Unexpected EOF in load_bsdf_rep()\n", progname);
560 return(0);
561 }