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root/radiance/ray/src/gen/mkillum4.c
Revision: 2.11
Committed: Fri Apr 11 20:07:12 2008 UTC (16 years ago) by greg
Content type: text/plain
Branch: MAIN
CVS Tags: rad3R9
Changes since 2.10: +10 -9 lines
Log Message:
Fixed angle orientation

File Contents

# Content
1 #ifndef lint
2 static const char RCSid[] = "$Id: mkillum4.c,v 2.10 2008/03/27 01:40:30 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 */
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 v[2] = d = cos(alt);
81 d = sqrt(1. - d*d); /* sin(alt) */
82 v[0] = cos(azi)*d;
83 v[1] = sin(azi)*d;
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 v[2] = -v[2];
155
156 return(1);
157 }
158
159
160 static int
161 ab_getndxR( /* get index corresponding to the reverse vector */
162 FVECT v,
163 void *p
164 )
165 {
166 FVECT v2;
167
168 v2[0] = -v[0];
169 v2[1] = -v[1];
170 v2[2] = -v[2];
171
172 return ab_getndx(v2, p);
173 }
174
175
176 static void
177 load_bsdf_data( /* load BSDF distribution for this wavelength */
178 struct BSDF_data *dp,
179 ezxml_t wdb
180 )
181 {
182 char *cbasis = ezxml_txt(ezxml_child(wdb,"ColumnAngleBasis"));
183 char *rbasis = ezxml_txt(ezxml_child(wdb,"RowAngleBasis"));
184 char *sdata;
185 int i;
186
187 if ((cbasis == NULL) | (rbasis == NULL)) {
188 error(WARNING, "missing column/row basis for BSDF");
189 return;
190 }
191 /* XXX need to add routines for loading in foreign bases */
192 for (i = nabases; i--; )
193 if (!strcmp(cbasis, abase_list[i].name)) {
194 dp->ninc = abase_list[i].nangles;
195 dp->ib_priv = (void *)&abase_list[i];
196 dp->ib_vec = ab_getvecR;
197 dp->ib_ndx = ab_getndxR;
198 dp->ib_ohm = ab_getohm;
199 break;
200 }
201 if (i < 0) {
202 sprintf(errmsg, "unsupported ColumnAngleBasis '%s'", cbasis);
203 error(WARNING, errmsg);
204 return;
205 }
206 for (i = nabases; i--; )
207 if (!strcmp(rbasis, abase_list[i].name)) {
208 dp->nout = abase_list[i].nangles;
209 dp->ob_priv = (void *)&abase_list[i];
210 dp->ob_vec = ab_getvec;
211 dp->ob_ndx = ab_getndx;
212 dp->ob_ohm = ab_getohm;
213 break;
214 }
215 if (i < 0) {
216 sprintf(errmsg, "unsupported RowAngleBasis '%s'", cbasis);
217 error(WARNING, errmsg);
218 return;
219 }
220 /* read BSDF data */
221 sdata = ezxml_txt(ezxml_child(wdb,"ScatteringData"));
222 if (sdata == NULL) {
223 error(WARNING, "missing BSDF ScatteringData");
224 return;
225 }
226 dp->bsdf = (float *)malloc(sizeof(float)*dp->ninc*dp->nout);
227 if (dp->bsdf == NULL)
228 error(SYSTEM, "out of memory in load_bsdf_data");
229 for (i = 0; i < dp->ninc*dp->nout; i++) {
230 char *sdnext = fskip(sdata);
231 if (sdnext == NULL) {
232 error(WARNING, "bad/missing BSDF ScatteringData");
233 free(dp->bsdf); dp->bsdf = NULL;
234 return;
235 }
236 while (*sdnext && isspace(*sdnext))
237 sdnext++;
238 if (*sdnext == ',') sdnext++;
239 dp->bsdf[i] = atof(sdata);
240 sdata = sdnext;
241 }
242 while (isspace(*sdata))
243 sdata++;
244 if (*sdata) {
245 sprintf(errmsg, "%d extra characters after BSDF ScatteringData",
246 strlen(sdata));
247 error(WARNING, errmsg);
248 }
249 }
250
251
252 struct BSDF_data *
253 load_BSDF( /* load BSDF data from file */
254 char *fname
255 )
256 {
257 char *path;
258 ezxml_t fl, wtl, wld, wdb;
259 struct BSDF_data *dp;
260
261 path = getpath(fname, getrlibpath(), R_OK);
262 if (path == NULL) {
263 sprintf(errmsg, "cannot find BSDF file \"%s\"", fname);
264 error(WARNING, errmsg);
265 return(NULL);
266 }
267 fl = ezxml_parse_file(path);
268 if (fl == NULL) {
269 sprintf(errmsg, "cannot open BSDF \"%s\"", path);
270 error(WARNING, errmsg);
271 return(NULL);
272 }
273 if (ezxml_error(fl)[0]) {
274 sprintf(errmsg, "BSDF \"%s\" %s", path, ezxml_error(fl));
275 error(WARNING, errmsg);
276 ezxml_free(fl);
277 return(NULL);
278 }
279 if (strcmp(ezxml_name(fl), "WindowElement")) {
280 sprintf(errmsg,
281 "BSDF \"%s\": top level node not 'WindowElement'",
282 path);
283 error(WARNING, errmsg);
284 ezxml_free(fl);
285 return(NULL);
286 }
287 wtl = ezxml_child(ezxml_child(fl, "Optical"), "Layer");
288 dp = (struct BSDF_data *)calloc(1, sizeof(struct BSDF_data));
289 for (wld = ezxml_child(wtl, "WavelengthData");
290 wld != NULL; wld = wld->next) {
291 if (strcmp(ezxml_txt(ezxml_child(wld,"Wavelength")), "Visible"))
292 continue;
293 wdb = ezxml_child(wld, "WavelengthDataBlock");
294 if (wdb == NULL) continue;
295 if (strcmp(ezxml_txt(ezxml_child(wdb,"WavelengthDataDirection")),
296 "Transmission Front"))
297 continue;
298 load_bsdf_data(dp, wdb); /* load front BTDF */
299 break; /* ignore the rest */
300 }
301 ezxml_free(fl); /* done with XML file */
302 if (dp->bsdf == NULL) {
303 sprintf(errmsg, "bad/missing BTDF data in \"%s\"", path);
304 error(WARNING, errmsg);
305 free_BSDF(dp);
306 dp = NULL;
307 }
308 return(dp);
309 }
310
311
312 void
313 free_BSDF( /* free BSDF data structure */
314 struct BSDF_data *b
315 )
316 {
317 if (b == NULL)
318 return;
319 if (b->bsdf != NULL)
320 free(b->bsdf);
321 free(b);
322 }
323
324
325 int
326 r_BSDF_incvec( /* compute random input vector at given location */
327 FVECT v,
328 struct BSDF_data *b,
329 int i,
330 double rv,
331 MAT4 xm
332 )
333 {
334 FVECT pert;
335 double rad;
336 int j;
337
338 if (!getBSDF_incvec(v, b, i))
339 return(0);
340 rad = sqrt(getBSDF_incohm(b, i) / PI);
341 multisamp(pert, 3, rv);
342 for (j = 0; j < 3; j++)
343 v[j] += rad*(2.*pert[j] - 1.);
344 if (xm != NULL)
345 multv3(v, v, xm);
346 return(normalize(v) != 0.0);
347 }
348
349
350 int
351 r_BSDF_outvec( /* compute random output vector at given location */
352 FVECT v,
353 struct BSDF_data *b,
354 int o,
355 double rv,
356 MAT4 xm
357 )
358 {
359 FVECT pert;
360 double rad;
361 int j;
362
363 if (!getBSDF_outvec(v, b, o))
364 return(0);
365 rad = sqrt(getBSDF_outohm(b, o) / PI);
366 multisamp(pert, 3, rv);
367 for (j = 0; j < 3; j++)
368 v[j] += rad*(2.*pert[j] - 1.);
369 if (xm != NULL)
370 multv3(v, v, xm);
371 return(normalize(v) != 0.0);
372 }
373
374
375 #define FEQ(a,b) ((a)-(b) <= 1e-7 && (b)-(a) <= 1e-7)
376
377 static int
378 addrot( /* compute rotation (x,y,z) => (xp,yp,zp) */
379 char *xfarg[],
380 FVECT xp,
381 FVECT yp,
382 FVECT zp
383 )
384 {
385 static char bufs[3][16];
386 int bn = 0;
387 char **xfp = xfarg;
388 double theta;
389
390 if (yp[2]*yp[2] + zp[2]*zp[2] < 2.*FTINY*FTINY) {
391 /* Special case for X' along Z-axis */
392 theta = -atan2(yp[0], yp[1]);
393 *xfp++ = "-ry";
394 *xfp++ = xp[2] < 0.0 ? "90" : "-90";
395 *xfp++ = "-rz";
396 sprintf(bufs[bn], "%f", theta*(180./PI));
397 *xfp++ = bufs[bn++];
398 return(xfp - xfarg);
399 }
400 theta = atan2(yp[2], zp[2]);
401 if (!FEQ(theta,0.0)) {
402 *xfp++ = "-rx";
403 sprintf(bufs[bn], "%f", theta*(180./PI));
404 *xfp++ = bufs[bn++];
405 }
406 theta = asin(-xp[2]);
407 if (!FEQ(theta,0.0)) {
408 *xfp++ = "-ry";
409 sprintf(bufs[bn], " %f", theta*(180./PI));
410 *xfp++ = bufs[bn++];
411 }
412 theta = atan2(xp[1], xp[0]);
413 if (!FEQ(theta,0.0)) {
414 *xfp++ = "-rz";
415 sprintf(bufs[bn], "%f", theta*(180./PI));
416 *xfp++ = bufs[bn++];
417 }
418 *xfp = NULL;
419 return(xfp - xfarg);
420 }
421
422
423 int
424 getBSDF_xfm( /* compute BSDF orient. -> world orient. transform */
425 MAT4 xm,
426 FVECT nrm,
427 UpDir ud
428 )
429 {
430 char *xfargs[7];
431 XF myxf;
432 FVECT updir, xdest, ydest;
433
434 updir[0] = updir[1] = updir[2] = 0.;
435 switch (ud) {
436 case UDzneg:
437 updir[2] = -1.;
438 break;
439 case UDyneg:
440 updir[1] = -1.;
441 break;
442 case UDxneg:
443 updir[0] = -1.;
444 break;
445 case UDxpos:
446 updir[0] = 1.;
447 break;
448 case UDypos:
449 updir[1] = 1.;
450 break;
451 case UDzpos:
452 updir[2] = 1.;
453 break;
454 case UDunknown:
455 return(0);
456 }
457 fcross(xdest, updir, nrm);
458 if (normalize(xdest) == 0.0)
459 return(0);
460 fcross(ydest, nrm, xdest);
461 xf(&myxf, addrot(xfargs, xdest, ydest, nrm), xfargs);
462 copymat4(xm, myxf.xfm);
463 return(1);
464 }
465
466
467 void
468 redistribute( /* pass distarr ray sums through BSDF */
469 struct BSDF_data *b,
470 int nalt,
471 int nazi,
472 FVECT u,
473 FVECT v,
474 FVECT w,
475 MAT4 xm
476 )
477 {
478 int nout = 0;
479 MAT4 mymat, inmat;
480 COLORV *idist;
481 COLORV *cp, *csum;
482 FVECT dv;
483 double wt;
484 int i, j, k, o;
485 COLOR col, cinc;
486 /* copy incoming distribution */
487 if (b->ninc != distsiz)
488 error(INTERNAL, "error 1 in redistribute");
489 idist = (COLORV *)malloc(sizeof(COLOR)*distsiz);
490 if (idist == NULL)
491 error(SYSTEM, "out of memory in redistribute");
492 memcpy(idist, distarr, sizeof(COLOR)*distsiz);
493 /* compose direction transform */
494 for (i = 3; i--; ) {
495 mymat[i][0] = u[i];
496 mymat[i][1] = v[i];
497 mymat[i][2] = w[i];
498 mymat[i][3] = 0.;
499 }
500 mymat[3][0] = mymat[3][1] = mymat[3][2] = 0.;
501 mymat[3][3] = 1.;
502 if (xm != NULL)
503 multmat4(mymat, xm, mymat);
504 for (i = 3; i--; ) { /* make sure it's normalized */
505 wt = 1./sqrt( mymat[0][i]*mymat[0][i] +
506 mymat[1][i]*mymat[1][i] +
507 mymat[2][i]*mymat[2][i] );
508 for (j = 3; j--; )
509 mymat[j][i] *= wt;
510 }
511 if (!invmat4(inmat, mymat)) /* need inverse as well */
512 error(INTERNAL, "cannot invert BSDF transform");
513 newdist(nalt*nazi); /* resample distribution */
514 for (i = b->ninc; i--; ) {
515 getBSDF_incvec(dv, b, i); /* compute incident irrad. */
516 multv3(dv, dv, mymat);
517 if (dv[2] < 0.0) dv[2] = -dv[2];
518 wt = getBSDF_incohm(b, i);
519 wt *= dv[2]; /* solid_angle*cosine(theta) */
520 cp = &idist[3*i];
521 copycolor(cinc, cp);
522 scalecolor(cinc, wt);
523 for (k = nalt; k--; ) /* loop over distribution */
524 for (j = nazi; j--; ) {
525 flatdir(dv, (k + .5)/nalt, (double)j/nazi);
526 multv3(dv, dv, inmat);
527 /* evaluate BSDF @ outgoing */
528 o = getBSDF_outndx(b, dv);
529 if (o < 0) {
530 nout++;
531 continue;
532 }
533 wt = BSDF_value(b, i, o);
534 copycolor(col, cinc);
535 scalecolor(col, wt);
536 csum = &distarr[3*(k*nazi + j)];
537 addcolor(csum, col); /* sum into distribution */
538 }
539 }
540 free(idist); /* free temp space */
541 if (nout) {
542 sprintf(errmsg, "missing %.1f%% of BSDF directions",
543 100.*nout/(b->ninc*nalt*nazi));
544 error(WARNING, errmsg);
545 }
546 }