| 17 |
|
/* |
| 18 |
|
* Arguments to this material include optional diffuse colors. |
| 19 |
|
* String arguments include the BSDF and function files. |
| 20 |
< |
* A thickness variable causes the strange but useful behavior |
| 21 |
< |
* of translating transmitted rays this distance past the surface |
| 22 |
< |
* intersection in the normal direction to bypass intervening geometry. |
| 23 |
< |
* This only affects scattered, non-source directed samples. Thus, |
| 24 |
< |
* thickness is relevant only if there is a transmitted component. |
| 25 |
< |
* A positive thickness has the further side-effect that an unscattered |
| 20 |
> |
* A non-zero thickness causes the strange but useful behavior |
| 21 |
> |
* of translating transmitted rays this distance beneath the surface |
| 22 |
> |
* (opposite the surface normal) to bypass any intervening geometry. |
| 23 |
> |
* Translation only affects scattered, non-source-directed samples. |
| 24 |
> |
* A non-zero thickness has the further side-effect that an unscattered |
| 25 |
|
* (view) ray will pass right through our material if it has any |
| 26 |
< |
* non-diffuse transmission, making our BSDF invisible. This allows the |
| 27 |
< |
* underlying geometry to become visible. A matching surface should be |
| 28 |
< |
* placed on the other side, less than the thickness away, if the backside |
| 29 |
< |
* reflectance is non-zero. |
| 26 |
> |
* non-diffuse transmission, making the BSDF surface invisible. This |
| 27 |
> |
* shows the proxied geometry instead. Thickness has the further |
| 28 |
> |
* effect of turning off reflection on the hidden side so that rays |
| 29 |
> |
* heading in the opposite direction pass unimpeded through the BSDF |
| 30 |
> |
* surface. A paired surface may be placed on the opposide side of |
| 31 |
> |
* the detail geometry, less than this thickness away, if a two-way |
| 32 |
> |
* proxy is desired. Note that the sign of the thickness is important. |
| 33 |
> |
* A positive thickness hides geometry behind the BSDF surface and uses |
| 34 |
> |
* front reflectance and transmission properties. A negative thickness |
| 35 |
> |
* hides geometry in front of the surface when rays hit from behind, |
| 36 |
> |
* and applies only the transmission and backside reflectance properties. |
| 37 |
> |
* Reflection is ignored on the hidden side, as those rays pass through. |
| 38 |
|
* The "up" vector for the BSDF is given by three variables, defined |
| 39 |
|
* (along with the thickness) by the named function file, or '.' if none. |
| 40 |
|
* Together with the surface normal, this defines the local coordinate |
| 41 |
|
* system for the BSDF. |
| 42 |
|
* We do not reorient the surface, so if the BSDF has no back-side |
| 43 |
< |
* reflectance and none is given in the real arguments, the surface will |
| 44 |
< |
* appear as black when viewed from behind (unless backvis is false). |
| 45 |
< |
* The diffuse compnent arguments are added to components in the BSDF file, |
| 43 |
> |
* reflectance and none is given in the real arguments, a BSDF surface |
| 44 |
> |
* with zero thickness will appear black when viewed from behind |
| 45 |
> |
* unless backface visibility is off. |
| 46 |
> |
* The diffuse arguments are added to components in the BSDF file, |
| 47 |
|
* not multiplied. However, patterns affect this material as a multiplier |
| 48 |
|
* on everything except non-diffuse reflection. |
| 49 |
|
* |
| 96 |
|
normalize(vres); |
| 97 |
|
} |
| 98 |
|
|
| 99 |
< |
/* Compute source contribution for BSDF */ |
| 99 |
> |
/* Evaluate BSDF for direct component, returning true if OK to proceed */ |
| 100 |
> |
static int |
| 101 |
> |
direct_bsdf_OK(COLOR cval, FVECT ldir, BSDFDAT *ndp) |
| 102 |
> |
{ |
| 103 |
> |
FVECT vsrc, vjit; |
| 104 |
> |
SDValue sv; |
| 105 |
> |
SDError ec; |
| 106 |
> |
/* transform source direction */ |
| 107 |
> |
if (SDmapDir(vsrc, ndp->toloc, ldir) != SDEnone) |
| 108 |
> |
return(0); |
| 109 |
> |
/* jitter query direction */ |
| 110 |
> |
bsdf_jitter(vjit, ndp); |
| 111 |
> |
/* avoid indirect over-counting */ |
| 112 |
> |
if (ndp->thick != .0 && ndp->pr->crtype & (SPECULAR|AMBIENT) && |
| 113 |
> |
vsrc[2] > .0 ^ vjit[2] > .0) { |
| 114 |
> |
double dx = vsrc[0] + vjit[0]; |
| 115 |
> |
double dy = vsrc[1] + vjit[1]; |
| 116 |
> |
if (dx*dx + dy*dy <= ndp->sr_vpsa*ndp->sr_vpsa) |
| 117 |
> |
return(0); |
| 118 |
> |
} |
| 119 |
> |
ec = SDevalBSDF(&sv, vjit, vsrc, ndp->sd); |
| 120 |
> |
if (ec) |
| 121 |
> |
objerror(ndp->mp, USER, transSDError(ec)); |
| 122 |
> |
|
| 123 |
> |
if (sv.cieY <= FTINY) /* not worth using? */ |
| 124 |
> |
return(0); |
| 125 |
> |
/* else we're good to go */ |
| 126 |
> |
cvt_sdcolor(cval, &sv); |
| 127 |
> |
return(1); |
| 128 |
> |
} |
| 129 |
> |
|
| 130 |
> |
/* Compute source contribution for BSDF (reflected & transmitted) */ |
| 131 |
|
static void |
| 132 |
< |
dirbsdf( |
| 132 |
> |
dir_bsdf( |
| 133 |
|
COLOR cval, /* returned coefficient */ |
| 134 |
|
void *nnp, /* material data */ |
| 135 |
|
FVECT ldir, /* light source direction */ |
| 137 |
|
) |
| 138 |
|
{ |
| 139 |
|
BSDFDAT *np = (BSDFDAT *)nnp; |
| 101 |
– |
SDError ec; |
| 102 |
– |
SDValue sv; |
| 103 |
– |
FVECT vsrc; |
| 104 |
– |
FVECT vjit; |
| 140 |
|
double ldot; |
| 141 |
|
double dtmp; |
| 142 |
|
COLOR ctmp; |
| 168 |
|
/* |
| 169 |
|
* Compute scattering coefficient using BSDF. |
| 170 |
|
*/ |
| 171 |
< |
if (SDmapDir(vsrc, np->toloc, ldir) != SDEnone) |
| 171 |
> |
if (!direct_bsdf_OK(ctmp, ldir, np)) |
| 172 |
|
return; |
| 138 |
– |
bsdf_jitter(vjit, np); |
| 139 |
– |
ec = SDevalBSDF(&sv, vjit, vsrc, np->sd); |
| 140 |
– |
if (ec) |
| 141 |
– |
objerror(np->mp, USER, transSDError(ec)); |
| 142 |
– |
|
| 143 |
– |
if (sv.cieY <= FTINY) /* not worth using? */ |
| 144 |
– |
return; |
| 145 |
– |
cvt_sdcolor(ctmp, &sv); |
| 173 |
|
if (ldot > .0) { /* pattern only diffuse reflection */ |
| 174 |
|
COLOR ctmp1, ctmp2; |
| 175 |
|
dtmp = (np->pr->rod > .0) ? np->sd->rLambFront.cieY |
| 176 |
|
: np->sd->rLambBack.cieY; |
| 177 |
< |
dtmp /= PI * sv.cieY; /* diffuse fraction */ |
| 177 |
> |
/* diffuse fraction */ |
| 178 |
> |
dtmp /= PI * bright(ctmp); |
| 179 |
|
copycolor(ctmp2, np->pr->pcol); |
| 180 |
|
scalecolor(ctmp2, dtmp); |
| 181 |
|
setcolor(ctmp1, 1.-dtmp, 1.-dtmp, 1.-dtmp); |
| 190 |
|
addcolor(cval, ctmp); |
| 191 |
|
} |
| 192 |
|
|
| 193 |
+ |
/* Compute source contribution for BSDF (reflected only) */ |
| 194 |
+ |
static void |
| 195 |
+ |
dir_brdf( |
| 196 |
+ |
COLOR cval, /* returned coefficient */ |
| 197 |
+ |
void *nnp, /* material data */ |
| 198 |
+ |
FVECT ldir, /* light source direction */ |
| 199 |
+ |
double omega /* light source size */ |
| 200 |
+ |
) |
| 201 |
+ |
{ |
| 202 |
+ |
BSDFDAT *np = (BSDFDAT *)nnp; |
| 203 |
+ |
double ldot; |
| 204 |
+ |
double dtmp; |
| 205 |
+ |
COLOR ctmp, ctmp1, ctmp2; |
| 206 |
+ |
|
| 207 |
+ |
setcolor(cval, .0, .0, .0); |
| 208 |
+ |
|
| 209 |
+ |
ldot = DOT(np->pnorm, ldir); |
| 210 |
+ |
|
| 211 |
+ |
if (ldot <= FTINY) |
| 212 |
+ |
return; |
| 213 |
+ |
|
| 214 |
+ |
if (bright(np->rdiff) > FTINY) { |
| 215 |
+ |
/* |
| 216 |
+ |
* Compute added diffuse reflected component. |
| 217 |
+ |
*/ |
| 218 |
+ |
copycolor(ctmp, np->rdiff); |
| 219 |
+ |
dtmp = ldot * omega * (1./PI); |
| 220 |
+ |
scalecolor(ctmp, dtmp); |
| 221 |
+ |
addcolor(cval, ctmp); |
| 222 |
+ |
} |
| 223 |
+ |
/* |
| 224 |
+ |
* Compute reflection coefficient using BSDF. |
| 225 |
+ |
*/ |
| 226 |
+ |
if (!direct_bsdf_OK(ctmp, ldir, np)) |
| 227 |
+ |
return; |
| 228 |
+ |
/* pattern only diffuse reflection */ |
| 229 |
+ |
dtmp = (np->pr->rod > .0) ? np->sd->rLambFront.cieY |
| 230 |
+ |
: np->sd->rLambBack.cieY; |
| 231 |
+ |
dtmp /= PI * bright(ctmp); /* diffuse fraction */ |
| 232 |
+ |
copycolor(ctmp2, np->pr->pcol); |
| 233 |
+ |
scalecolor(ctmp2, dtmp); |
| 234 |
+ |
setcolor(ctmp1, 1.-dtmp, 1.-dtmp, 1.-dtmp); |
| 235 |
+ |
addcolor(ctmp1, ctmp2); |
| 236 |
+ |
multcolor(ctmp, ctmp1); /* apply derated pattern */ |
| 237 |
+ |
dtmp = ldot * omega; |
| 238 |
+ |
scalecolor(ctmp, dtmp); |
| 239 |
+ |
addcolor(cval, ctmp); |
| 240 |
+ |
} |
| 241 |
+ |
|
| 242 |
+ |
/* Compute source contribution for BSDF (transmitted only) */ |
| 243 |
+ |
static void |
| 244 |
+ |
dir_btdf( |
| 245 |
+ |
COLOR cval, /* returned coefficient */ |
| 246 |
+ |
void *nnp, /* material data */ |
| 247 |
+ |
FVECT ldir, /* light source direction */ |
| 248 |
+ |
double omega /* light source size */ |
| 249 |
+ |
) |
| 250 |
+ |
{ |
| 251 |
+ |
BSDFDAT *np = (BSDFDAT *)nnp; |
| 252 |
+ |
double ldot; |
| 253 |
+ |
double dtmp; |
| 254 |
+ |
COLOR ctmp; |
| 255 |
+ |
|
| 256 |
+ |
setcolor(cval, .0, .0, .0); |
| 257 |
+ |
|
| 258 |
+ |
ldot = DOT(np->pnorm, ldir); |
| 259 |
+ |
|
| 260 |
+ |
if (ldot >= -FTINY) |
| 261 |
+ |
return; |
| 262 |
+ |
|
| 263 |
+ |
if (bright(np->tdiff) > FTINY) { |
| 264 |
+ |
/* |
| 265 |
+ |
* Compute added diffuse transmission. |
| 266 |
+ |
*/ |
| 267 |
+ |
copycolor(ctmp, np->tdiff); |
| 268 |
+ |
dtmp = -ldot * omega * (1.0/PI); |
| 269 |
+ |
scalecolor(ctmp, dtmp); |
| 270 |
+ |
addcolor(cval, ctmp); |
| 271 |
+ |
} |
| 272 |
+ |
/* |
| 273 |
+ |
* Compute scattering coefficient using BSDF. |
| 274 |
+ |
*/ |
| 275 |
+ |
if (!direct_bsdf_OK(ctmp, ldir, np)) |
| 276 |
+ |
return; |
| 277 |
+ |
/* full pattern on transmission */ |
| 278 |
+ |
multcolor(ctmp, np->pr->pcol); |
| 279 |
+ |
dtmp = -ldot * omega; |
| 280 |
+ |
scalecolor(ctmp, dtmp); |
| 281 |
+ |
addcolor(cval, ctmp); |
| 282 |
+ |
} |
| 283 |
+ |
|
| 284 |
|
/* Sample separate BSDF component */ |
| 285 |
|
static int |
| 286 |
|
sample_sdcomp(BSDFDAT *ndp, SDComponent *dcp, int usepat) |
| 329 |
|
++nsent; /* Russian roulette victim */ |
| 330 |
|
continue; |
| 331 |
|
} |
| 332 |
< |
if (ndp->thick > FTINY) { /* need to move origin? */ |
| 333 |
< |
sthick = (ndp->pr->rod > .0) ? -ndp->thick : ndp->thick; |
| 334 |
< |
if (sthick < .0 ^ vsmp[2] > .0) |
| 216 |
< |
VSUM(sr.rorg, sr.rorg, ndp->pr->ron, sthick); |
| 217 |
< |
} |
| 332 |
> |
/* need to offset origin? */ |
| 333 |
> |
if (ndp->thick != .0 && ndp->pr->rod > .0 ^ vsmp[2] > .0) |
| 334 |
> |
VSUM(sr.rorg, sr.rorg, ndp->pr->ron, -ndp->thick); |
| 335 |
|
rayvalue(&sr); /* send & evaluate sample */ |
| 336 |
|
multcolor(sr.rcol, sr.rcoef); |
| 337 |
|
addcolor(ndp->pr->rcol, sr.rcol); |
| 397 |
|
int |
| 398 |
|
m_bsdf(OBJREC *m, RAY *r) |
| 399 |
|
{ |
| 400 |
+ |
int hitfront; |
| 401 |
|
COLOR ctmp; |
| 402 |
|
SDError ec; |
| 403 |
< |
FVECT upvec, outVec; |
| 403 |
> |
FVECT upvec, vtmp; |
| 404 |
|
MFUNC *mf; |
| 405 |
|
BSDFDAT nd; |
| 406 |
|
/* check arguments */ |
| 407 |
|
if ((m->oargs.nsargs < 6) | (m->oargs.nfargs > 9) | |
| 408 |
|
(m->oargs.nfargs % 3)) |
| 409 |
|
objerror(m, USER, "bad # arguments"); |
| 410 |
< |
|
| 411 |
< |
/* get BSDF data */ |
| 294 |
< |
nd.sd = loadBSDF(m->oargs.sarg[1]); |
| 410 |
> |
/* record surface struck */ |
| 411 |
> |
hitfront = (r->rod > .0); |
| 412 |
|
/* load cal file */ |
| 413 |
|
mf = getfunc(m, 5, 0x1d, 1); |
| 414 |
|
/* get thickness */ |
| 415 |
|
nd.thick = evalue(mf->ep[0]); |
| 416 |
< |
if (nd.thick < .0) |
| 416 |
> |
if ((-FTINY <= nd.thick) & (nd.thick <= FTINY)) |
| 417 |
|
nd.thick = .0; |
| 418 |
|
/* check shadow */ |
| 419 |
|
if (r->crtype & SHADOW) { |
| 420 |
< |
if ((nd.thick > FTINY) & (nd.sd->tf != NULL)) |
| 420 |
> |
if (nd.thick != .0) |
| 421 |
|
raytrans(r); /* pass-through */ |
| 422 |
< |
SDfreeCache(nd.sd); |
| 306 |
< |
return(1); /* else shadow */ |
| 422 |
> |
return(1); /* or shadow */ |
| 423 |
|
} |
| 424 |
< |
/* check unscattered ray */ |
| 425 |
< |
if (!(r->crtype & (SPECULAR|AMBIENT)) && |
| 426 |
< |
(nd.thick > FTINY) & (nd.sd->tf != NULL)) { |
| 427 |
< |
SDfreeCache(nd.sd); |
| 312 |
< |
raytrans(r); /* pass-through */ |
| 424 |
> |
/* check other rays to pass */ |
| 425 |
> |
if (nd.thick != .0 && (!(r->crtype & (SPECULAR|AMBIENT)) || |
| 426 |
> |
nd.thick > .0 ^ hitfront)) { |
| 427 |
> |
raytrans(r); /* hide our proxy */ |
| 428 |
|
return(1); |
| 429 |
|
} |
| 430 |
+ |
/* get BSDF data */ |
| 431 |
+ |
nd.sd = loadBSDF(m->oargs.sarg[1]); |
| 432 |
|
/* diffuse reflectance */ |
| 433 |
< |
if (r->rod > .0) { |
| 433 |
> |
if (hitfront) { |
| 434 |
|
if (m->oargs.nfargs < 3) |
| 435 |
|
setcolor(nd.rdiff, .0, .0, .0); |
| 436 |
|
else |
| 462 |
|
nd.pr = r; |
| 463 |
|
/* get modifiers */ |
| 464 |
|
raytexture(r, m->omod); |
| 348 |
– |
if (bright(r->pcol) <= FTINY) { /* black pattern?! */ |
| 349 |
– |
SDfreeCache(nd.sd); |
| 350 |
– |
return(1); |
| 351 |
– |
} |
| 465 |
|
/* modify diffuse values */ |
| 466 |
|
multcolor(nd.rdiff, r->pcol); |
| 467 |
|
multcolor(nd.tdiff, r->pcol); |
| 495 |
|
SDfreeCache(nd.sd); |
| 496 |
|
return(1); |
| 497 |
|
} |
| 498 |
< |
|
| 386 |
< |
if (r->rod < .0) { /* perturb normal towards hit */ |
| 498 |
> |
if (!hitfront) { /* perturb normal towards hit */ |
| 499 |
|
nd.pnorm[0] = -nd.pnorm[0]; |
| 500 |
|
nd.pnorm[1] = -nd.pnorm[1]; |
| 501 |
|
nd.pnorm[2] = -nd.pnorm[2]; |
| 507 |
|
/* compute indirect diffuse */ |
| 508 |
|
copycolor(ctmp, nd.rdiff); |
| 509 |
|
addcolor(ctmp, nd.runsamp); |
| 510 |
< |
if (bright(ctmp) > FTINY) { /* ambient from this side */ |
| 511 |
< |
if (r->rod < .0) |
| 510 |
> |
if (bright(ctmp) > FTINY) { /* ambient from reflection */ |
| 511 |
> |
if (!hitfront) |
| 512 |
|
flipsurface(r); |
| 513 |
|
multambient(ctmp, r, nd.pnorm); |
| 514 |
|
addcolor(r->rcol, ctmp); |
| 515 |
< |
if (r->rod < .0) |
| 515 |
> |
if (!hitfront) |
| 516 |
|
flipsurface(r); |
| 517 |
|
} |
| 518 |
|
copycolor(ctmp, nd.tdiff); |
| 519 |
|
addcolor(ctmp, nd.tunsamp); |
| 520 |
|
if (bright(ctmp) > FTINY) { /* ambient from other side */ |
| 521 |
|
FVECT bnorm; |
| 522 |
< |
if (r->rod > .0) |
| 522 |
> |
if (hitfront) |
| 523 |
|
flipsurface(r); |
| 524 |
|
bnorm[0] = -nd.pnorm[0]; |
| 525 |
|
bnorm[1] = -nd.pnorm[1]; |
| 526 |
|
bnorm[2] = -nd.pnorm[2]; |
| 527 |
< |
multambient(ctmp, r, bnorm); |
| 527 |
> |
if (nd.thick != .0) { /* proxy with offset? */ |
| 528 |
> |
VCOPY(vtmp, r->rop); |
| 529 |
> |
VSUM(r->rop, vtmp, r->ron, -nd.thick); |
| 530 |
> |
multambient(ctmp, r, bnorm); |
| 531 |
> |
VCOPY(r->rop, vtmp); |
| 532 |
> |
} else |
| 533 |
> |
multambient(ctmp, r, bnorm); |
| 534 |
|
addcolor(r->rcol, ctmp); |
| 535 |
< |
if (r->rod > .0) |
| 535 |
> |
if (hitfront) |
| 536 |
|
flipsurface(r); |
| 537 |
|
} |
| 538 |
|
/* add direct component */ |
| 539 |
< |
direct(r, dirbsdf, &nd); |
| 539 |
> |
if ((bright(nd.tdiff) <= FTINY) & (nd.sd->tf == NULL)) { |
| 540 |
> |
direct(r, dir_brdf, &nd); /* reflection only */ |
| 541 |
> |
} else if (nd.thick == .0) { |
| 542 |
> |
direct(r, dir_bsdf, &nd); /* thin surface scattering */ |
| 543 |
> |
} else { |
| 544 |
> |
direct(r, dir_brdf, &nd); /* reflection first */ |
| 545 |
> |
VCOPY(vtmp, r->rop); /* offset for transmitted */ |
| 546 |
> |
VSUM(r->rop, vtmp, r->ron, -nd.thick); |
| 547 |
> |
direct(r, dir_btdf, &nd); /* separate transmission */ |
| 548 |
> |
VCOPY(r->rop, vtmp); |
| 549 |
> |
} |
| 550 |
|
/* clean up */ |
| 551 |
|
SDfreeCache(nd.sd); |
| 552 |
|
return(1); |
