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root/radiance/ray/src/gen/mkillum4.c
Revision: 2.10
Committed: Thu Mar 27 01:40:30 2008 UTC (17 years, 1 month ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.9: +13 -4 lines
Log Message:
Updated for newer XML format of BSDF data

File Contents

# Content
1 #ifndef lint
2 static const char RCSid[] = "$Id: mkillum4.c,v 2.9 2008/01/25 02:11:13 greg Exp $";
3 #endif
4 /*
5 * Routines for handling BSDF data within mkillum
6 */
7
8 #include "mkillum.h"
9 #include "paths.h"
10 #include "ezxml.h"
11
12 #define MAXLATS 46 /* maximum number of latitudes */
13
14 /* BSDF angle specification (terminate with nphi = -1) */
15 typedef struct {
16 char name[64]; /* basis name */
17 int nangles; /* total number of directions */
18 struct {
19 float tmin; /* starting theta */
20 short nphis; /* number of phis (0 term) */
21 } lat[MAXLATS+1]; /* latitudes */
22 } ANGLE_BASIS;
23
24 #define MAXABASES 3 /* limit on defined bases */
25
26 ANGLE_BASIS abase_list[MAXABASES] = {
27 {
28 "LBNL/Klems Full", 145,
29 { {-5., 1},
30 {5., 8},
31 {15., 16},
32 {25., 20},
33 {35., 24},
34 {45., 24},
35 {55., 24},
36 {65., 16},
37 {75., 12},
38 {90., 0} }
39 }, {
40 "LBNL/Klems Half", 73,
41 { {-6.5, 1},
42 {6.5, 8},
43 {19.5, 12},
44 {32.5, 16},
45 {46.5, 20},
46 {61.5, 12},
47 {76.5, 4},
48 {90., 0} }
49 }, {
50 "LBNL/Klems Quarter", 41,
51 { {-9., 1},
52 {9., 8},
53 {27., 12},
54 {46., 12},
55 {66., 8},
56 {90., 0} }
57 }
58 };
59
60 static int nabases = 3; /* current number of defined bases */
61
62
63 static int
64 ab_getvec( /* get vector for this angle basis index */
65 FVECT v,
66 int ndx,
67 void *p
68 )
69 {
70 ANGLE_BASIS *ab = (ANGLE_BASIS *)p;
71 int li;
72 double alt, azi, d;
73
74 if ((ndx < 0) | (ndx >= ab->nangles))
75 return(0);
76 for (li = 0; ndx >= ab->lat[li].nphis; li++)
77 ndx -= ab->lat[li].nphis;
78 alt = PI/180.*0.5*(ab->lat[li].tmin + ab->lat[li+1].tmin);
79 azi = 2.*PI*ndx/ab->lat[li].nphis;
80 d = sin(alt);
81 v[0] = cos(azi)*d;
82 v[1] = sin(azi)*d;
83 v[2] = cos(alt);
84 return(1);
85 }
86
87
88 static int
89 ab_getndx( /* get index corresponding to the given vector */
90 FVECT v,
91 void *p
92 )
93 {
94 ANGLE_BASIS *ab = (ANGLE_BASIS *)p;
95 int li, ndx;
96 double alt, azi, d;
97
98 if ((v[2] < -1.0) | (v[2] > 1.0))
99 return(-1);
100 alt = 180.0/PI*acos(v[2]);
101 azi = 180.0/PI*atan2(v[1], v[0]);
102 if (azi < 0.0) azi += 360.0;
103 for (li = 1; ab->lat[li].tmin <= alt; li++)
104 if (!ab->lat[li].nphis)
105 return(-1);
106 --li;
107 ndx = (int)((1./360.)*azi*ab->lat[li].nphis + 0.5);
108 if (ndx >= ab->lat[li].nphis) ndx = 0;
109 while (li--)
110 ndx += ab->lat[li].nphis;
111 return(ndx);
112 }
113
114
115 static double
116 ab_getohm( /* get solid angle for this angle basis index */
117 int ndx,
118 void *p
119 )
120 {
121 ANGLE_BASIS *ab = (ANGLE_BASIS *)p;
122 int li;
123 double tdia, pdia;
124
125 if ((ndx < 0) | (ndx >= ab->nangles))
126 return(0);
127 for (li = 0; ndx >= ab->lat[li].nphis; li++)
128 ndx -= ab->lat[li].nphis;
129 if (ab->lat[li].nphis == 1) { /* special case */
130 if (ab->lat[li].tmin > FTINY)
131 error(USER, "unsupported BSDF coordinate system");
132 tdia = PI/180. * ab->lat[li+1].tmin;
133 return(PI*tdia*tdia);
134 }
135 tdia = PI/180.*(ab->lat[li+1].tmin - ab->lat[li].tmin);
136 tdia *= sin(PI/180.*(ab->lat[li].tmin + ab->lat[li+1].tmin));
137 pdia = 2.*PI/ab->lat[li].nphis;
138 return(tdia*pdia);
139 }
140
141
142 static int
143 ab_getvecR( /* get reverse vector for this angle basis index */
144 FVECT v,
145 int ndx,
146 void *p
147 )
148 {
149 if (!ab_getvec(v, ndx, p))
150 return(0);
151
152 v[0] = -v[0];
153 v[1] = -v[1];
154
155 return(1);
156 }
157
158
159 static int
160 ab_getndxR( /* get index corresponding to the reverse vector */
161 FVECT v,
162 void *p
163 )
164 {
165 FVECT v2;
166
167 v2[0] = -v[0];
168 v2[1] = -v[1];
169 v2[2] = v[2];
170
171 return ab_getndx(v2, p);
172 }
173
174
175 static void
176 load_bsdf_data( /* load BSDF distribution for this wavelength */
177 struct BSDF_data *dp,
178 ezxml_t wdb
179 )
180 {
181 char *cbasis = ezxml_txt(ezxml_child(wdb,"ColumnAngleBasis"));
182 char *rbasis = ezxml_txt(ezxml_child(wdb,"RowAngleBasis"));
183 char *sdata;
184 int i;
185
186 if ((cbasis == NULL) | (rbasis == NULL)) {
187 error(WARNING, "missing column/row basis for BSDF");
188 return;
189 }
190 /* XXX need to add routines for loading in foreign bases */
191 for (i = nabases; i--; )
192 if (!strcmp(cbasis, abase_list[i].name)) {
193 dp->ninc = abase_list[i].nangles;
194 dp->ib_priv = (void *)&abase_list[i];
195 dp->ib_vec = ab_getvec;
196 dp->ib_ndx = ab_getndx;
197 dp->ib_ohm = ab_getohm;
198 break;
199 }
200 if (i < 0) {
201 sprintf(errmsg, "unsupported ColumnAngleBasis '%s'", cbasis);
202 error(WARNING, errmsg);
203 return;
204 }
205 for (i = nabases; i--; )
206 if (!strcmp(rbasis, abase_list[i].name)) {
207 dp->nout = abase_list[i].nangles;
208 dp->ob_priv = (void *)&abase_list[i];
209 dp->ob_vec = ab_getvecR;
210 dp->ob_ndx = ab_getndxR;
211 dp->ob_ohm = ab_getohm;
212 break;
213 }
214 if (i < 0) {
215 sprintf(errmsg, "unsupported RowAngleBasis '%s'", cbasis);
216 error(WARNING, errmsg);
217 return;
218 }
219 /* read BSDF data */
220 sdata = ezxml_txt(ezxml_child(wdb,"ScatteringData"));
221 if (sdata == NULL) {
222 error(WARNING, "missing BSDF ScatteringData");
223 return;
224 }
225 dp->bsdf = (float *)malloc(sizeof(float)*dp->ninc*dp->nout);
226 if (dp->bsdf == NULL)
227 error(SYSTEM, "out of memory in load_bsdf_data");
228 for (i = 0; i < dp->ninc*dp->nout; i++) {
229 char *sdnext = fskip(sdata);
230 if (sdnext == NULL) {
231 error(WARNING, "bad/missing BSDF ScatteringData");
232 free(dp->bsdf); dp->bsdf = NULL;
233 return;
234 }
235 while (*sdnext && isspace(*sdnext))
236 sdnext++;
237 if (*sdnext == ',') sdnext++;
238 dp->bsdf[i] = atof(sdata);
239 sdata = sdnext;
240 }
241 while (isspace(*sdata))
242 sdata++;
243 if (*sdata) {
244 sprintf(errmsg, "%d extra characters after BSDF ScatteringData",
245 strlen(sdata));
246 error(WARNING, errmsg);
247 }
248 }
249
250
251 struct BSDF_data *
252 load_BSDF( /* load BSDF data from file */
253 char *fname
254 )
255 {
256 char *path;
257 ezxml_t fl, wtl, wld, wdb;
258 struct BSDF_data *dp;
259
260 path = getpath(fname, getrlibpath(), R_OK);
261 if (path == NULL) {
262 sprintf(errmsg, "cannot find BSDF file \"%s\"", fname);
263 error(WARNING, errmsg);
264 return(NULL);
265 }
266 fl = ezxml_parse_file(path);
267 if (fl == NULL) {
268 sprintf(errmsg, "cannot open BSDF \"%s\"", path);
269 error(WARNING, errmsg);
270 return(NULL);
271 }
272 if (ezxml_error(fl)[0]) {
273 sprintf(errmsg, "BSDF \"%s\" %s", path, ezxml_error(fl));
274 error(WARNING, errmsg);
275 ezxml_free(fl);
276 return(NULL);
277 }
278 if (strcmp(ezxml_name(fl), "WindowElement")) {
279 sprintf(errmsg,
280 "BSDF \"%s\": top level node not 'WindowElement'",
281 path);
282 error(WARNING, errmsg);
283 ezxml_free(fl);
284 return(NULL);
285 }
286 wtl = ezxml_child(ezxml_child(fl, "Optical"), "Layer");
287 dp = (struct BSDF_data *)calloc(1, sizeof(struct BSDF_data));
288 for (wld = ezxml_child(wtl, "WavelengthData");
289 wld != NULL; wld = wld->next) {
290 if (strcmp(ezxml_txt(ezxml_child(wld,"Wavelength")), "Visible"))
291 continue;
292 wdb = ezxml_child(wld, "WavelengthDataBlock");
293 if (wdb == NULL) continue;
294 if (strcmp(ezxml_txt(ezxml_child(wdb,"WavelengthDataDirection")),
295 "Transmission Front"))
296 continue;
297 load_bsdf_data(dp, wdb); /* load front BTDF */
298 break; /* ignore the rest */
299 }
300 ezxml_free(fl); /* done with XML file */
301 if (dp->bsdf == NULL) {
302 sprintf(errmsg, "bad/missing BTDF data in \"%s\"", path);
303 error(WARNING, errmsg);
304 free_BSDF(dp);
305 dp = NULL;
306 }
307 return(dp);
308 }
309
310
311 void
312 free_BSDF( /* free BSDF data structure */
313 struct BSDF_data *b
314 )
315 {
316 if (b == NULL)
317 return;
318 if (b->bsdf != NULL)
319 free(b->bsdf);
320 free(b);
321 }
322
323
324 int
325 r_BSDF_incvec( /* compute random input vector at given location */
326 FVECT v,
327 struct BSDF_data *b,
328 int i,
329 double rv,
330 MAT4 xm
331 )
332 {
333 FVECT pert;
334 double rad;
335 int j;
336
337 if (!getBSDF_incvec(v, b, i))
338 return(0);
339 rad = sqrt(getBSDF_incohm(b, i) / PI);
340 multisamp(pert, 3, rv);
341 for (j = 0; j < 3; j++)
342 v[j] += rad*(2.*pert[j] - 1.);
343 if (xm != NULL)
344 multv3(v, v, xm);
345 return(normalize(v) != 0.0);
346 }
347
348
349 int
350 r_BSDF_outvec( /* compute random output vector at given location */
351 FVECT v,
352 struct BSDF_data *b,
353 int o,
354 double rv,
355 MAT4 xm
356 )
357 {
358 FVECT pert;
359 double rad;
360 int j;
361
362 if (!getBSDF_outvec(v, b, o))
363 return(0);
364 rad = sqrt(getBSDF_outohm(b, o) / PI);
365 multisamp(pert, 3, rv);
366 for (j = 0; j < 3; j++)
367 v[j] += rad*(2.*pert[j] - 1.);
368 if (xm != NULL)
369 multv3(v, v, xm);
370 return(normalize(v) != 0.0);
371 }
372
373
374 #define FEQ(a,b) ((a)-(b) <= 1e-7 && (b)-(a) <= 1e-7)
375
376 static int
377 addrot( /* compute rotation (x,y,z) => (xp,yp,zp) */
378 char *xfarg[],
379 FVECT xp,
380 FVECT yp,
381 FVECT zp
382 )
383 {
384 static char bufs[3][16];
385 int bn = 0;
386 char **xfp = xfarg;
387 double theta;
388
389 if (yp[2]*yp[2] + zp[2]*zp[2] < 2.*FTINY*FTINY) {
390 /* Special case for X' along Z-axis */
391 theta = -atan2(yp[0], yp[1]);
392 *xfp++ = "-ry";
393 *xfp++ = xp[2] < 0.0 ? "90" : "-90";
394 *xfp++ = "-rz";
395 sprintf(bufs[bn], "%f", theta*(180./PI));
396 *xfp++ = bufs[bn++];
397 return(xfp - xfarg);
398 }
399 theta = atan2(yp[2], zp[2]);
400 if (!FEQ(theta,0.0)) {
401 *xfp++ = "-rx";
402 sprintf(bufs[bn], "%f", theta*(180./PI));
403 *xfp++ = bufs[bn++];
404 }
405 theta = asin(-xp[2]);
406 if (!FEQ(theta,0.0)) {
407 *xfp++ = "-ry";
408 sprintf(bufs[bn], " %f", theta*(180./PI));
409 *xfp++ = bufs[bn++];
410 }
411 theta = atan2(xp[1], xp[0]);
412 if (!FEQ(theta,0.0)) {
413 *xfp++ = "-rz";
414 sprintf(bufs[bn], "%f", theta*(180./PI));
415 *xfp++ = bufs[bn++];
416 }
417 *xfp = NULL;
418 return(xfp - xfarg);
419 }
420
421
422 int
423 getBSDF_xfm( /* compute BSDF orient. -> world orient. transform */
424 MAT4 xm,
425 FVECT nrm,
426 UpDir ud
427 )
428 {
429 char *xfargs[7];
430 XF myxf;
431 FVECT updir, xdest, ydest;
432
433 updir[0] = updir[1] = updir[2] = 0.;
434 switch (ud) {
435 case UDzneg:
436 updir[2] = -1.;
437 break;
438 case UDyneg:
439 updir[1] = -1.;
440 break;
441 case UDxneg:
442 updir[0] = -1.;
443 break;
444 case UDxpos:
445 updir[0] = 1.;
446 break;
447 case UDypos:
448 updir[1] = 1.;
449 break;
450 case UDzpos:
451 updir[2] = 1.;
452 break;
453 case UDunknown:
454 return(0);
455 }
456 fcross(xdest, updir, nrm);
457 if (normalize(xdest) == 0.0)
458 return(0);
459 fcross(ydest, nrm, xdest);
460 xf(&myxf, addrot(xfargs, xdest, ydest, nrm), xfargs);
461 copymat4(xm, myxf.xfm);
462 return(1);
463 }
464
465
466 void
467 redistribute( /* pass distarr ray sums through BSDF */
468 struct BSDF_data *b,
469 int nalt,
470 int nazi,
471 FVECT u,
472 FVECT v,
473 FVECT w,
474 MAT4 xm
475 )
476 {
477 int nout = 0;
478 MAT4 mymat, inmat;
479 COLORV *idist;
480 COLORV *cp, *csum;
481 FVECT dv;
482 double wt;
483 int i, j, k, o;
484 COLOR col, cinc;
485 /* copy incoming distribution */
486 if (b->ninc != distsiz)
487 error(INTERNAL, "error 1 in redistribute");
488 idist = (COLORV *)malloc(sizeof(COLOR)*distsiz);
489 if (idist == NULL)
490 error(SYSTEM, "out of memory in redistribute");
491 memcpy(idist, distarr, sizeof(COLOR)*distsiz);
492 /* compose direction transform */
493 for (i = 3; i--; ) {
494 mymat[i][0] = u[i];
495 mymat[i][1] = v[i];
496 mymat[i][2] = w[i];
497 mymat[i][3] = 0.;
498 }
499 mymat[3][0] = mymat[3][1] = mymat[3][2] = 0.;
500 mymat[3][3] = 1.;
501 if (xm != NULL)
502 multmat4(mymat, xm, mymat);
503 for (i = 3; i--; ) { /* make sure it's normalized */
504 wt = 1./sqrt( mymat[0][i]*mymat[0][i] +
505 mymat[1][i]*mymat[1][i] +
506 mymat[2][i]*mymat[2][i] );
507 for (j = 3; j--; )
508 mymat[j][i] *= wt;
509 }
510 if (!invmat4(inmat, mymat)) /* need inverse as well */
511 error(INTERNAL, "cannot invert BSDF transform");
512 newdist(nalt*nazi); /* resample distribution */
513 for (i = b->ninc; i--; ) {
514 getBSDF_incvec(dv, b, i); /* compute incident irrad. */
515 multv3(dv, dv, mymat);
516 if (dv[2] < 0.0) dv[2] = -dv[2];
517 wt = getBSDF_incohm(b, i);
518 wt *= dv[2]; /* solid_angle*cosine(theta) */
519 cp = &idist[3*i];
520 copycolor(cinc, cp);
521 scalecolor(cinc, wt);
522 for (k = nalt; k--; ) /* loop over distribution */
523 for (j = nazi; j--; ) {
524 flatdir(dv, (k + .5)/nalt, (double)j/nazi);
525 multv3(dv, dv, inmat);
526 /* evaluate BSDF @ outgoing */
527 o = getBSDF_outndx(b, dv);
528 if (o < 0) {
529 nout++;
530 continue;
531 }
532 wt = BSDF_value(b, i, o);
533 copycolor(col, cinc);
534 scalecolor(col, wt);
535 csum = &distarr[3*(k*nazi + j)];
536 addcolor(csum, col); /* sum into distribution */
537 }
538 }
539 free(idist); /* free temp space */
540 if (nout) {
541 sprintf(errmsg, "missing %.1f%% of BSDF directions",
542 100.*nout/(b->ninc*nalt*nazi));
543 error(WARNING, errmsg);
544 }
545 }