| 25 |
|
#define MAXITER 10 /* maximum # specular ray attempts */ |
| 26 |
|
#endif |
| 27 |
|
/* estimate of Fresnel function */ |
| 28 |
< |
#define FRESNE(ci) (exp(-5.85*(ci)) - 0.00287989916) |
| 28 |
> |
#define FRESNE(ci) (exp(-6.2*(ci)) - 0.00202943064) |
| 29 |
|
#define FRESTHRESH 0.017999 /* minimum specularity for approx. */ |
| 30 |
|
|
| 31 |
|
|
| 182 |
|
{ |
| 183 |
|
NORMDAT nd; |
| 184 |
|
double fest; |
| 185 |
– |
double transtest, transdist; |
| 186 |
– |
double mirtest, mirdist; |
| 185 |
|
int hastexture; |
| 186 |
|
double d; |
| 187 |
|
COLOR ctmp; |
| 231 |
|
if (nd.pdot < .001) |
| 232 |
|
nd.pdot = .001; /* non-zero for dirnorm() */ |
| 233 |
|
multcolor(nd.mcolor, r->pcol); /* modify material color */ |
| 236 |
– |
mirtest = transtest = 0; |
| 237 |
– |
mirdist = transdist = r->rot; |
| 234 |
|
nd.rspec = m->oargs.farg[3]; |
| 235 |
|
/* compute Fresnel approx. */ |
| 236 |
|
if (nd.specfl & SP_PURE && nd.rspec >= FRESTHRESH) { |
| 251 |
|
nd.specfl |= SP_TBLT; |
| 252 |
|
if (!hastexture || r->crtype & (SHADOW|AMBIENT)) { |
| 253 |
|
VCOPY(nd.prdir, r->rdir); |
| 258 |
– |
transtest = 2; |
| 254 |
|
} else { |
| 255 |
|
/* perturb */ |
| 256 |
|
VSUB(nd.prdir, r->rdir, r->pert); |
| 262 |
|
} |
| 263 |
|
} else |
| 264 |
|
nd.tdiff = nd.tspec = nd.trans = 0.0; |
| 265 |
+ |
/* diffuse reflection */ |
| 266 |
+ |
nd.rdiff = 1.0 - nd.trans - nd.rspec; |
| 267 |
|
/* transmitted ray */ |
| 271 |
– |
|
| 268 |
|
if ((nd.specfl&(SP_TRAN|SP_PURE|SP_TBLT)) == (SP_TRAN|SP_PURE)) { |
| 269 |
|
RAY lr; |
| 270 |
|
copycolor(lr.rcoef, nd.mcolor); /* modified by color */ |
| 274 |
|
rayvalue(&lr); |
| 275 |
|
multcolor(lr.rcol, lr.rcoef); |
| 276 |
|
addcolor(r->rcol, lr.rcol); |
| 277 |
< |
transtest *= bright(lr.rcol); |
| 278 |
< |
transdist = r->rot + lr.rt; |
| 277 |
> |
if (nd.tspec >= 1.0-FTINY) { |
| 278 |
> |
/* completely transparent */ |
| 279 |
> |
multcolor(lr.mcol, lr.rcoef); |
| 280 |
> |
copycolor(r->mcol, lr.mcol); |
| 281 |
> |
r->rmt = r->rot + lr.rmt; |
| 282 |
> |
r->rxt = r->rot + lr.rxt; |
| 283 |
> |
} else if (nd.tspec > nd.tdiff + nd.rdiff) |
| 284 |
> |
r->rxt = r->rot + raydistance(&lr); |
| 285 |
|
} |
| 286 |
< |
} else |
| 285 |
< |
transtest = 0; |
| 286 |
> |
} |
| 287 |
|
|
| 288 |
< |
if (r->crtype & SHADOW) { /* the rest is shadow */ |
| 288 |
< |
r->rt = transdist; |
| 288 |
> |
if (r->crtype & SHADOW) /* the rest is shadow */ |
| 289 |
|
return(1); |
| 290 |
– |
} |
| 290 |
|
/* get specular reflection */ |
| 291 |
|
if (nd.rspec > FTINY) { |
| 292 |
|
nd.specfl |= SP_REFL; |
| 319 |
|
VCOPY(lr.rdir, nd.vrefl); |
| 320 |
|
rayvalue(&lr); |
| 321 |
|
multcolor(lr.rcol, lr.rcoef); |
| 322 |
+ |
copycolor(r->mcol, lr.rcol); |
| 323 |
|
addcolor(r->rcol, lr.rcol); |
| 324 |
+ |
r->rmt = r->rot; |
| 325 |
|
if (nd.specfl & SP_FLAT && |
| 326 |
< |
!hastexture | (r->crtype & AMBIENT)) { |
| 327 |
< |
mirtest = 2.*bright(lr.rcol); |
| 327 |
< |
mirdist = r->rot + lr.rt; |
| 328 |
< |
} |
| 326 |
> |
!hastexture | (r->crtype & AMBIENT)) |
| 327 |
> |
r->rmt += raydistance(&lr); |
| 328 |
|
} |
| 329 |
|
} |
| 331 |
– |
/* diffuse reflection */ |
| 332 |
– |
nd.rdiff = 1.0 - nd.trans - nd.rspec; |
| 330 |
|
|
| 331 |
< |
if (nd.specfl & SP_PURE && nd.rdiff <= FTINY && nd.tdiff <= FTINY) { |
| 335 |
< |
if (mirtest > transtest+FTINY) |
| 336 |
< |
r->rt = mirdist; |
| 337 |
< |
else if (transtest > FTINY) |
| 338 |
< |
r->rt = transdist; |
| 331 |
> |
if (nd.specfl & SP_PURE && nd.rdiff <= FTINY && nd.tdiff <= FTINY) |
| 332 |
|
return(1); /* 100% pure specular */ |
| 333 |
< |
} |
| 333 |
> |
|
| 334 |
|
if (!(nd.specfl & SP_PURE)) |
| 335 |
|
gaussamp(&nd); /* checks *BLT flags */ |
| 336 |
|
|
| 362 |
|
} |
| 363 |
|
/* add direct component */ |
| 364 |
|
direct(r, dirnorm, &nd); |
| 372 |
– |
/* check distance */ |
| 373 |
– |
d = bright(r->rcol); |
| 374 |
– |
if (transtest > d) |
| 375 |
– |
r->rt = transdist; |
| 376 |
– |
else if (mirtest > d) |
| 377 |
– |
r->rt = mirdist; |
| 365 |
|
|
| 366 |
|
return(1); |
| 367 |
|
} |
