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root/radiance/ray/src/cv/bsdfrep.c
Revision: 2.12
Committed: Wed Mar 20 01:00:22 2013 UTC (11 years, 1 month ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.11: +18 -4 lines
Log Message:
Added minimum BSDF to output where we have no data.

File Contents

# User Rev Content
1 greg 2.1 #ifndef lint
2 greg 2.12 static const char RCSid[] = "$Id: bsdfrep.c,v 2.11 2012/11/22 06:07:17 greg Exp $";
3 greg 2.1 #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 greg 2.2 #include <string.h>
13 greg 2.1 #include <math.h>
14     #include "rtio.h"
15     #include "resolu.h"
16     #include "bsdfrep.h"
17 greg 2.5 /* active grid resolution */
18     int grid_res = GRIDRES;
19    
20 greg 2.4 /* coverage/symmetry using INP_QUAD? flags */
21 greg 2.1 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 greg 2.12 /* BSDF histogram */
30     int bsdf_hist[HISTLEN];
31    
32     /* BSDF value for boundary regions */
33     double bsdf_min = 0;
34    
35 greg 2.1 /* 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 greg 2.6 if ((theta_in_deg = new_theta) < 1.0)
66     return(1); /* don't rely on phi near normal */
67 greg 2.1 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 greg 2.11 const double phi = get_phi360(vec);
92 greg 2.1
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 greg 2.5 rbf->rbfa[n].gx = grid_res-1 - rbf->rbfa[n].gx;
182 greg 2.1 if (sym & MIRROR_Y)
183     for (n = rbf->nrbf; n-- > 0; )
184 greg 2.5 rbf->rbfa[n].gy = grid_res-1 - rbf->rbfa[n].gy;
185 greg 2.1 }
186    
187 greg 2.6 /* 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 greg 2.8
198 greg 2.10 for (n = ((-.01 > phi) | (phi > .01))*rbf->nrbf; n-- > 0; ) {
199 greg 2.6 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 greg 2.1 /* Compute volume associated with Gaussian lobe */
209     double
210     rbf_volume(const RBFVAL *rbfp)
211     {
212     double rad = R2ANG(rbfp->crad);
213    
214     return((2.*M_PI) * rbfp->peak * rad*rad);
215     }
216    
217     /* Compute outgoing vector from grid position */
218     void
219     ovec_from_pos(FVECT vec, int xpos, int ypos)
220     {
221     double uv[2];
222     double r2;
223    
224 greg 2.8 SDsquare2disk(uv, (xpos+.5)/grid_res, (ypos+.5)/grid_res);
225 greg 2.1 /* uniform hemispherical projection */
226     r2 = uv[0]*uv[0] + uv[1]*uv[1];
227     vec[0] = vec[1] = sqrt(2. - r2);
228     vec[0] *= uv[0];
229     vec[1] *= uv[1];
230     vec[2] = output_orient*(1. - r2);
231     }
232    
233     /* Compute grid position from normalized input/output vector */
234     void
235     pos_from_vec(int pos[2], const FVECT vec)
236     {
237     double sq[2]; /* uniform hemispherical projection */
238     double norm = 1./sqrt(1. + fabs(vec[2]));
239    
240     SDdisk2square(sq, vec[0]*norm, vec[1]*norm);
241    
242 greg 2.5 pos[0] = (int)(sq[0]*grid_res);
243     pos[1] = (int)(sq[1]*grid_res);
244 greg 2.1 }
245    
246     /* Evaluate RBF for DSF at the given normalized outgoing direction */
247     double
248     eval_rbfrep(const RBFNODE *rp, const FVECT outvec)
249     {
250 greg 2.8 double res = 0;
251 greg 2.1 const RBFVAL *rbfp;
252     FVECT odir;
253     double sig2;
254     int n;
255 greg 2.12 /* use minimum if no information avail. */
256     if (rp == NULL) {
257     if (outvec[2] > 0 ^ output_orient > 0)
258     return(.0);
259     return(bsdf_min*output_orient*outvec[2]);
260     }
261 greg 2.1 rbfp = rp->rbfa;
262     for (n = rp->nrbf; n--; rbfp++) {
263     ovec_from_pos(odir, rbfp->gx, rbfp->gy);
264     sig2 = R2ANG(rbfp->crad);
265     sig2 = (DOT(odir,outvec) - 1.) / (sig2*sig2);
266     if (sig2 > -19.)
267     res += rbfp->peak * exp(sig2);
268     }
269     return(res);
270     }
271    
272     /* Insert a new directional scattering function in our global list */
273     int
274     insert_dsf(RBFNODE *newrbf)
275     {
276     RBFNODE *rbf, *rbf_last;
277     int pos;
278     /* check for redundant meas. */
279     for (rbf = dsf_list; rbf != NULL; rbf = rbf->next)
280     if (DOT(rbf->invec, newrbf->invec) >= 1.-FTINY) {
281     fprintf(stderr,
282     "%s: Duplicate incident measurement (ignored)\n",
283     progname);
284     free(newrbf);
285     return(-1);
286     }
287     /* keep in ascending theta order */
288     for (rbf_last = NULL, rbf = dsf_list; rbf != NULL;
289     rbf_last = rbf, rbf = rbf->next)
290     if (single_plane_incident && input_orient*rbf->invec[2] <
291     input_orient*newrbf->invec[2])
292     break;
293     if (rbf_last == NULL) { /* insert new node in list */
294     newrbf->ord = 0;
295     newrbf->next = dsf_list;
296     dsf_list = newrbf;
297     } else {
298     newrbf->ord = rbf_last->ord + 1;
299     newrbf->next = rbf;
300     rbf_last->next = newrbf;
301     }
302     rbf_last = newrbf;
303     while (rbf != NULL) { /* update ordinal positions */
304     rbf->ord = rbf_last->ord + 1;
305     rbf_last = rbf;
306     rbf = rbf->next;
307     }
308     return(newrbf->ord);
309     }
310    
311     /* Get the DSF indicated by its ordinal position */
312     RBFNODE *
313     get_dsf(int ord)
314     {
315     RBFNODE *rbf;
316    
317     for (rbf = dsf_list; rbf != NULL; rbf = rbf->next)
318 greg 2.3 if (rbf->ord == ord)
319 greg 2.1 return(rbf);
320     return(NULL);
321     }
322    
323     /* Get triangle surface orientation (unnormalized) */
324     void
325     tri_orient(FVECT vres, const FVECT v1, const FVECT v2, const FVECT v3)
326     {
327     FVECT v2minus1, v3minus2;
328    
329     VSUB(v2minus1, v2, v1);
330     VSUB(v3minus2, v3, v2);
331     VCROSS(vres, v2minus1, v3minus2);
332     }
333    
334     /* Determine if vertex order is reversed (inward normal) */
335     int
336     is_rev_tri(const FVECT v1, const FVECT v2, const FVECT v3)
337     {
338     FVECT tor;
339    
340     tri_orient(tor, v1, v2, v3);
341    
342     return(DOT(tor, v2) < 0.);
343     }
344    
345     /* Find vertices completing triangles on either side of the given edge */
346     int
347     get_triangles(RBFNODE *rbfv[2], const MIGRATION *mig)
348     {
349 greg 2.4 const MIGRATION *ej1, *ej2;
350 greg 2.1 RBFNODE *tv;
351    
352     rbfv[0] = rbfv[1] = NULL;
353     if (mig == NULL)
354     return(0);
355 greg 2.4 for (ej1 = mig->rbfv[0]->ejl; ej1 != NULL;
356     ej1 = nextedge(mig->rbfv[0],ej1)) {
357     if (ej1 == mig)
358 greg 2.1 continue;
359 greg 2.4 tv = opp_rbf(mig->rbfv[0],ej1);
360 greg 2.1 for (ej2 = tv->ejl; ej2 != NULL; ej2 = nextedge(tv,ej2))
361     if (opp_rbf(tv,ej2) == mig->rbfv[1]) {
362     rbfv[is_rev_tri(mig->rbfv[0]->invec,
363     mig->rbfv[1]->invec,
364     tv->invec)] = tv;
365     break;
366     }
367     }
368     return((rbfv[0] != NULL) + (rbfv[1] != NULL));
369     }
370    
371 greg 2.4 /* Clear our BSDF representation and free memory */
372     void
373     clear_bsdf_rep(void)
374     {
375     while (mig_list != NULL) {
376     MIGRATION *mig = mig_list;
377     mig_list = mig->next;
378     free(mig);
379     }
380     while (dsf_list != NULL) {
381     RBFNODE *rbf = dsf_list;
382     dsf_list = rbf->next;
383     free(rbf);
384     }
385     inp_coverage = 0;
386     single_plane_incident = -1;
387     input_orient = output_orient = 0;
388 greg 2.5 grid_res = GRIDRES;
389 greg 2.4 }
390    
391 greg 2.1 /* Write our BSDF mesh interpolant out to the given binary stream */
392     void
393     save_bsdf_rep(FILE *ofp)
394     {
395     RBFNODE *rbf;
396     MIGRATION *mig;
397     int i, n;
398     /* finish header */
399 greg 2.2 fprintf(ofp, "SYMMETRY=%d\n", !single_plane_incident * inp_coverage);
400     fprintf(ofp, "IO_SIDES= %d %d\n", input_orient, output_orient);
401 greg 2.5 fprintf(ofp, "GRIDRES=%d\n", grid_res);
402 greg 2.12 fprintf(ofp, "BSDFMIN=%g\n", bsdf_min);
403 greg 2.1 fputformat(BSDFREP_FMT, ofp);
404     fputc('\n', ofp);
405     /* write each DSF */
406     for (rbf = dsf_list; rbf != NULL; rbf = rbf->next) {
407     putint(rbf->ord, 4, ofp);
408     putflt(rbf->invec[0], ofp);
409     putflt(rbf->invec[1], ofp);
410     putflt(rbf->invec[2], ofp);
411     putflt(rbf->vtotal, ofp);
412     putint(rbf->nrbf, 4, ofp);
413     for (i = 0; i < rbf->nrbf; i++) {
414     putflt(rbf->rbfa[i].peak, ofp);
415     putint(rbf->rbfa[i].crad, 2, ofp);
416     putint(rbf->rbfa[i].gx, 1, ofp);
417     putint(rbf->rbfa[i].gy, 1, ofp);
418     }
419     }
420     putint(-1, 4, ofp); /* terminator */
421     /* write each migration matrix */
422 greg 2.2 for (mig = mig_list; mig != NULL; mig = mig->next) {
423     int zerocnt = 0;
424 greg 2.1 putint(mig->rbfv[0]->ord, 4, ofp);
425     putint(mig->rbfv[1]->ord, 4, ofp);
426 greg 2.2 /* write out as sparse data */
427 greg 2.1 n = mtx_nrows(mig) * mtx_ncols(mig);
428 greg 2.2 for (i = 0; i < n; i++) {
429 greg 2.3 if (zerocnt == 0xff) {
430     putint(0xff, 1, ofp); zerocnt = 0;
431 greg 2.2 }
432     if (mig->mtx[i] != 0) {
433     putint(zerocnt, 1, ofp); zerocnt = 0;
434     putflt(mig->mtx[i], ofp);
435     } else
436     ++zerocnt;
437     }
438     putint(zerocnt, 1, ofp);
439 greg 2.1 }
440     putint(-1, 4, ofp); /* terminator */
441     putint(-1, 4, ofp);
442     if (fflush(ofp) == EOF) {
443     fprintf(stderr, "%s: error writing BSDF interpolant\n",
444     progname);
445     exit(1);
446     }
447     }
448    
449 greg 2.2 /* Check header line for critical information */
450     static int
451     headline(char *s, void *p)
452     {
453     char fmt[32];
454    
455     if (!strncmp(s, "SYMMETRY=", 9)) {
456     inp_coverage = atoi(s+9);
457     single_plane_incident = !inp_coverage;
458     return(0);
459     }
460     if (!strncmp(s, "IO_SIDES=", 9)) {
461     sscanf(s+9, "%d %d", &input_orient, &output_orient);
462     return(0);
463     }
464 greg 2.5 if (!strncmp(s, "GRIDRES=", 8)) {
465     sscanf(s+8, "%d", &grid_res);
466     return(0);
467     }
468 greg 2.12 if (!strncmp(s, "BSDFMIN=", 8)) {
469     sscanf(s+8, "%lf", &bsdf_min);
470     return(0);
471     }
472 greg 2.2 if (formatval(fmt, s) && strcmp(fmt, BSDFREP_FMT))
473     return(-1);
474     return(0);
475     }
476    
477 greg 2.1 /* Read a BSDF mesh interpolant from the given binary stream */
478     int
479     load_bsdf_rep(FILE *ifp)
480     {
481     RBFNODE rbfh;
482     int from_ord, to_ord;
483     int i;
484 greg 2.4
485     clear_bsdf_rep();
486 greg 2.5 if (ifp == NULL)
487     return(0);
488 greg 2.2 if (getheader(ifp, headline, NULL) < 0 || single_plane_incident < 0 |
489     !input_orient | !output_orient) {
490 greg 2.1 fprintf(stderr, "%s: missing/bad format for BSDF interpolant\n",
491     progname);
492     return(0);
493     }
494     rbfh.next = NULL; /* read each DSF */
495     rbfh.ejl = NULL;
496     while ((rbfh.ord = getint(4, ifp)) >= 0) {
497     RBFNODE *newrbf;
498    
499     rbfh.invec[0] = getflt(ifp);
500     rbfh.invec[1] = getflt(ifp);
501     rbfh.invec[2] = getflt(ifp);
502 greg 2.9 if (normalize(rbfh.invec) == 0) {
503     fprintf(stderr, "%s: zero incident vector\n", progname);
504     return(0);
505     }
506 greg 2.3 rbfh.vtotal = getflt(ifp);
507 greg 2.1 rbfh.nrbf = getint(4, ifp);
508     newrbf = (RBFNODE *)malloc(sizeof(RBFNODE) +
509     sizeof(RBFVAL)*(rbfh.nrbf-1));
510     if (newrbf == NULL)
511     goto memerr;
512 greg 2.8 memcpy(newrbf, &rbfh, sizeof(RBFNODE)-sizeof(RBFVAL));
513 greg 2.1 for (i = 0; i < rbfh.nrbf; i++) {
514     newrbf->rbfa[i].peak = getflt(ifp);
515     newrbf->rbfa[i].crad = getint(2, ifp) & 0xffff;
516     newrbf->rbfa[i].gx = getint(1, ifp) & 0xff;
517     newrbf->rbfa[i].gy = getint(1, ifp) & 0xff;
518     }
519     if (feof(ifp))
520     goto badEOF;
521     /* insert in global list */
522     if (insert_dsf(newrbf) != rbfh.ord) {
523     fprintf(stderr, "%s: error adding DSF\n", progname);
524     return(0);
525     }
526     }
527     /* read each migration matrix */
528     while ((from_ord = getint(4, ifp)) >= 0 &&
529     (to_ord = getint(4, ifp)) >= 0) {
530     RBFNODE *from_rbf = get_dsf(from_ord);
531     RBFNODE *to_rbf = get_dsf(to_ord);
532     MIGRATION *newmig;
533     int n;
534    
535     if ((from_rbf == NULL) | (to_rbf == NULL)) {
536     fprintf(stderr,
537     "%s: bad DSF reference in migration edge\n",
538     progname);
539     return(0);
540     }
541     n = from_rbf->nrbf * to_rbf->nrbf;
542     newmig = (MIGRATION *)malloc(sizeof(MIGRATION) +
543     sizeof(float)*(n-1));
544     if (newmig == NULL)
545     goto memerr;
546     newmig->rbfv[0] = from_rbf;
547     newmig->rbfv[1] = to_rbf;
548 greg 2.2 memset(newmig->mtx, 0, sizeof(float)*n);
549     for (i = 0; ; ) { /* read sparse data */
550     int zc = getint(1, ifp) & 0xff;
551     if ((i += zc) >= n)
552     break;
553 greg 2.3 if (zc == 0xff)
554     continue;
555 greg 2.2 newmig->mtx[i++] = getflt(ifp);
556     }
557 greg 2.1 if (feof(ifp))
558     goto badEOF;
559     /* insert in edge lists */
560     newmig->enxt[0] = from_rbf->ejl;
561     from_rbf->ejl = newmig;
562     newmig->enxt[1] = to_rbf->ejl;
563     to_rbf->ejl = newmig;
564     /* push onto global list */
565     newmig->next = mig_list;
566     mig_list = newmig;
567     }
568     return(1); /* success! */
569     memerr:
570     fprintf(stderr, "%s: Out of memory in load_bsdf_rep()\n", progname);
571     exit(1);
572     badEOF:
573     fprintf(stderr, "%s: Unexpected EOF in load_bsdf_rep()\n", progname);
574     return(0);
575     }