| 1 |
#ifndef lint |
| 2 |
static const char RCSid[] = "$Id: mkillum4.c,v 2.8 2007/12/13 07:03:37 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); |
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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]); |
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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 |
} |
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|
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|
| 115 |
static double |
| 116 |
ab_getohm( /* get solid angle for this angle basis index */ |
| 117 |
int ndx, |
| 118 |
void *p |
| 119 |
) |
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{ |
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ANGLE_BASIS *ab = (ANGLE_BASIS *)p; |
| 122 |
int li; |
| 123 |
double tdia, pdia; |
| 124 |
|
| 125 |
if ((ndx < 0) | (ndx >= ab->nangles)) |
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return(0); |
| 127 |
for (li = 0; ndx >= ab->lat[li].nphis; li++) |
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ndx -= ab->lat[li].nphis; |
| 129 |
if (ab->lat[li].nphis == 1) { /* special case */ |
| 130 |
if (ab->lat[li].tmin > FTINY) |
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error(USER, "unsupported BSDF coordinate system"); |
| 132 |
tdia = PI/180. * ab->lat[li+1].tmin; |
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return(PI*tdia*tdia); |
| 134 |
} |
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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 |
|
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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]; |
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v2[2] = v[2]; |
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|
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return ab_getndx(v2, p); |
| 172 |
} |
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|
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|
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static void |
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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)) { |
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error(WARNING, "missing column/row basis for BSDF"); |
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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)) { |
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dp->ninc = abase_list[i].nangles; |
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dp->ib_priv = (void *)&abase_list[i]; |
| 195 |
dp->ib_vec = ab_getvec; |
| 196 |
dp->ib_ndx = ab_getndx; |
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dp->ib_ohm = ab_getohm; |
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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, 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 |
dp = (struct BSDF_data *)calloc(1, sizeof(struct BSDF_data)); |
| 279 |
for (wld = ezxml_child(fl, "WavelengthData"); |
| 280 |
wld != NULL; wld = wld->next) { |
| 281 |
if (strcmp(ezxml_txt(ezxml_child(wld,"Wavelength")), "Visible")) |
| 282 |
continue; |
| 283 |
wdb = ezxml_child(wld, "WavelengthDataBlock"); |
| 284 |
if (wdb == NULL) continue; |
| 285 |
if (strcmp(ezxml_txt(ezxml_child(wdb,"WavelengthDataDirection")), |
| 286 |
"Transmission Front")) |
| 287 |
continue; |
| 288 |
load_bsdf_data(dp, wdb); /* load front BTDF */ |
| 289 |
break; /* ignore the rest */ |
| 290 |
} |
| 291 |
ezxml_free(fl); /* done with XML file */ |
| 292 |
if (dp->bsdf == NULL) { |
| 293 |
sprintf(errmsg, "bad/missing BTDF data in \"%s\"", path); |
| 294 |
error(WARNING, errmsg); |
| 295 |
free_BSDF(dp); |
| 296 |
dp = NULL; |
| 297 |
} |
| 298 |
return(dp); |
| 299 |
} |
| 300 |
|
| 301 |
|
| 302 |
void |
| 303 |
free_BSDF( /* free BSDF data structure */ |
| 304 |
struct BSDF_data *b |
| 305 |
) |
| 306 |
{ |
| 307 |
if (b == NULL) |
| 308 |
return; |
| 309 |
if (b->bsdf != NULL) |
| 310 |
free(b->bsdf); |
| 311 |
free(b); |
| 312 |
} |
| 313 |
|
| 314 |
|
| 315 |
int |
| 316 |
r_BSDF_incvec( /* compute random input vector at given location */ |
| 317 |
FVECT v, |
| 318 |
struct BSDF_data *b, |
| 319 |
int i, |
| 320 |
double rv, |
| 321 |
MAT4 xm |
| 322 |
) |
| 323 |
{ |
| 324 |
FVECT pert; |
| 325 |
double rad; |
| 326 |
int j; |
| 327 |
|
| 328 |
if (!getBSDF_incvec(v, b, i)) |
| 329 |
return(0); |
| 330 |
rad = sqrt(getBSDF_incohm(b, i) / PI); |
| 331 |
multisamp(pert, 3, rv); |
| 332 |
for (j = 0; j < 3; j++) |
| 333 |
v[j] += rad*(2.*pert[j] - 1.); |
| 334 |
if (xm != NULL) |
| 335 |
multv3(v, v, xm); |
| 336 |
return(normalize(v) != 0.0); |
| 337 |
} |
| 338 |
|
| 339 |
|
| 340 |
int |
| 341 |
r_BSDF_outvec( /* compute random output vector at given location */ |
| 342 |
FVECT v, |
| 343 |
struct BSDF_data *b, |
| 344 |
int o, |
| 345 |
double rv, |
| 346 |
MAT4 xm |
| 347 |
) |
| 348 |
{ |
| 349 |
FVECT pert; |
| 350 |
double rad; |
| 351 |
int j; |
| 352 |
|
| 353 |
if (!getBSDF_outvec(v, b, o)) |
| 354 |
return(0); |
| 355 |
rad = sqrt(getBSDF_outohm(b, o) / PI); |
| 356 |
multisamp(pert, 3, rv); |
| 357 |
for (j = 0; j < 3; j++) |
| 358 |
v[j] += rad*(2.*pert[j] - 1.); |
| 359 |
if (xm != NULL) |
| 360 |
multv3(v, v, xm); |
| 361 |
return(normalize(v) != 0.0); |
| 362 |
} |
| 363 |
|
| 364 |
|
| 365 |
#define FEQ(a,b) ((a)-(b) <= 1e-7 && (b)-(a) <= 1e-7) |
| 366 |
|
| 367 |
static int |
| 368 |
addrot( /* compute rotation (x,y,z) => (xp,yp,zp) */ |
| 369 |
char *xfarg[], |
| 370 |
FVECT xp, |
| 371 |
FVECT yp, |
| 372 |
FVECT zp |
| 373 |
) |
| 374 |
{ |
| 375 |
static char bufs[3][16]; |
| 376 |
int bn = 0; |
| 377 |
char **xfp = xfarg; |
| 378 |
double theta; |
| 379 |
|
| 380 |
if (yp[2]*yp[2] + zp[2]*zp[2] < 2.*FTINY*FTINY) { |
| 381 |
/* Special case for X' along Z-axis */ |
| 382 |
theta = -atan2(yp[0], yp[1]); |
| 383 |
*xfp++ = "-ry"; |
| 384 |
*xfp++ = xp[2] < 0.0 ? "90" : "-90"; |
| 385 |
*xfp++ = "-rz"; |
| 386 |
sprintf(bufs[bn], "%f", theta*(180./PI)); |
| 387 |
*xfp++ = bufs[bn++]; |
| 388 |
return(xfp - xfarg); |
| 389 |
} |
| 390 |
theta = atan2(yp[2], zp[2]); |
| 391 |
if (!FEQ(theta,0.0)) { |
| 392 |
*xfp++ = "-rx"; |
| 393 |
sprintf(bufs[bn], "%f", theta*(180./PI)); |
| 394 |
*xfp++ = bufs[bn++]; |
| 395 |
} |
| 396 |
theta = asin(-xp[2]); |
| 397 |
if (!FEQ(theta,0.0)) { |
| 398 |
*xfp++ = "-ry"; |
| 399 |
sprintf(bufs[bn], " %f", theta*(180./PI)); |
| 400 |
*xfp++ = bufs[bn++]; |
| 401 |
} |
| 402 |
theta = atan2(xp[1], xp[0]); |
| 403 |
if (!FEQ(theta,0.0)) { |
| 404 |
*xfp++ = "-rz"; |
| 405 |
sprintf(bufs[bn], "%f", theta*(180./PI)); |
| 406 |
*xfp++ = bufs[bn++]; |
| 407 |
} |
| 408 |
*xfp = NULL; |
| 409 |
return(xfp - xfarg); |
| 410 |
} |
| 411 |
|
| 412 |
|
| 413 |
int |
| 414 |
getBSDF_xfm( /* compute BSDF orient. -> world orient. transform */ |
| 415 |
MAT4 xm, |
| 416 |
FVECT nrm, |
| 417 |
UpDir ud |
| 418 |
) |
| 419 |
{ |
| 420 |
char *xfargs[7]; |
| 421 |
XF myxf; |
| 422 |
FVECT updir, xdest, ydest; |
| 423 |
|
| 424 |
updir[0] = updir[1] = updir[2] = 0.; |
| 425 |
switch (ud) { |
| 426 |
case UDzneg: |
| 427 |
updir[2] = -1.; |
| 428 |
break; |
| 429 |
case UDyneg: |
| 430 |
updir[1] = -1.; |
| 431 |
break; |
| 432 |
case UDxneg: |
| 433 |
updir[0] = -1.; |
| 434 |
break; |
| 435 |
case UDxpos: |
| 436 |
updir[0] = 1.; |
| 437 |
break; |
| 438 |
case UDypos: |
| 439 |
updir[1] = 1.; |
| 440 |
break; |
| 441 |
case UDzpos: |
| 442 |
updir[2] = 1.; |
| 443 |
break; |
| 444 |
case UDunknown: |
| 445 |
return(0); |
| 446 |
} |
| 447 |
fcross(xdest, updir, nrm); |
| 448 |
if (normalize(xdest) == 0.0) |
| 449 |
return(0); |
| 450 |
fcross(ydest, nrm, xdest); |
| 451 |
xf(&myxf, addrot(xfargs, xdest, ydest, nrm), xfargs); |
| 452 |
copymat4(xm, myxf.xfm); |
| 453 |
return(1); |
| 454 |
} |
| 455 |
|
| 456 |
|
| 457 |
void |
| 458 |
redistribute( /* pass distarr ray sums through BSDF */ |
| 459 |
struct BSDF_data *b, |
| 460 |
int nalt, |
| 461 |
int nazi, |
| 462 |
FVECT u, |
| 463 |
FVECT v, |
| 464 |
FVECT w, |
| 465 |
MAT4 xm |
| 466 |
) |
| 467 |
{ |
| 468 |
int nout = 0; |
| 469 |
MAT4 mymat, inmat; |
| 470 |
COLORV *idist; |
| 471 |
COLORV *cp, *csum; |
| 472 |
FVECT dv; |
| 473 |
double wt; |
| 474 |
int i, j, k, o; |
| 475 |
COLOR col, cinc; |
| 476 |
/* copy incoming distribution */ |
| 477 |
if (b->ninc != distsiz) |
| 478 |
error(INTERNAL, "error 1 in redistribute"); |
| 479 |
idist = (COLORV *)malloc(sizeof(COLOR)*distsiz); |
| 480 |
if (idist == NULL) |
| 481 |
error(SYSTEM, "out of memory in redistribute"); |
| 482 |
memcpy(idist, distarr, sizeof(COLOR)*distsiz); |
| 483 |
/* compose direction transform */ |
| 484 |
for (i = 3; i--; ) { |
| 485 |
mymat[i][0] = u[i]; |
| 486 |
mymat[i][1] = v[i]; |
| 487 |
mymat[i][2] = w[i]; |
| 488 |
mymat[i][3] = 0.; |
| 489 |
} |
| 490 |
mymat[3][0] = mymat[3][1] = mymat[3][2] = 0.; |
| 491 |
mymat[3][3] = 1.; |
| 492 |
if (xm != NULL) |
| 493 |
multmat4(mymat, xm, mymat); |
| 494 |
for (i = 3; i--; ) { /* make sure it's normalized */ |
| 495 |
wt = 1./sqrt( mymat[0][i]*mymat[0][i] + |
| 496 |
mymat[1][i]*mymat[1][i] + |
| 497 |
mymat[2][i]*mymat[2][i] ); |
| 498 |
for (j = 3; j--; ) |
| 499 |
mymat[j][i] *= wt; |
| 500 |
} |
| 501 |
if (!invmat4(inmat, mymat)) /* need inverse as well */ |
| 502 |
error(INTERNAL, "cannot invert BSDF transform"); |
| 503 |
newdist(nalt*nazi); /* resample distribution */ |
| 504 |
for (i = b->ninc; i--; ) { |
| 505 |
getBSDF_incvec(dv, b, i); /* compute incident irrad. */ |
| 506 |
multv3(dv, dv, mymat); |
| 507 |
if (dv[2] < 0.0) dv[2] = -dv[2]; |
| 508 |
wt = getBSDF_incohm(b, i); |
| 509 |
wt *= dv[2]; /* solid_angle*cosine(theta) */ |
| 510 |
cp = &idist[3*i]; |
| 511 |
copycolor(cinc, cp); |
| 512 |
scalecolor(cinc, wt); |
| 513 |
for (k = nalt; k--; ) /* loop over distribution */ |
| 514 |
for (j = nazi; j--; ) { |
| 515 |
flatdir(dv, (k + .5)/nalt, (double)j/nazi); |
| 516 |
multv3(dv, dv, inmat); |
| 517 |
/* evaluate BSDF @ outgoing */ |
| 518 |
o = getBSDF_outndx(b, dv); |
| 519 |
if (o < 0) { |
| 520 |
nout++; |
| 521 |
continue; |
| 522 |
} |
| 523 |
wt = BSDF_value(b, i, o); |
| 524 |
copycolor(col, cinc); |
| 525 |
scalecolor(col, wt); |
| 526 |
csum = &distarr[3*(k*nazi + j)]; |
| 527 |
addcolor(csum, col); /* sum into distribution */ |
| 528 |
} |
| 529 |
} |
| 530 |
free(idist); /* free temp space */ |
| 531 |
if (nout) { |
| 532 |
sprintf(errmsg, "missing %.1f%% of BSDF directions", |
| 533 |
100.*nout/(b->ninc*nalt*nazi)); |
| 534 |
error(WARNING, errmsg); |
| 535 |
} |
| 536 |
} |
