| 22 |
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| 23 |
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extern double ssampdist; /* scatter sampling distance */ |
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|
| 25 |
+ |
#ifndef MAXSSAMP |
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+ |
#define MAXSSAMP 16 /* maximum samples per ray */ |
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+ |
#endif |
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+ |
|
| 29 |
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/* |
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* Structures used by direct() |
| 31 |
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*/ |
| 337 |
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( sr.ro != source[scp->sno].so || |
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source[scp->sno].sflags & SFOLLOW )) { |
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/* follow entire path */ |
| 340 |
< |
if (!raycont(&sr)) |
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< |
objerror(sr.ro, USER, "material not found"); |
| 340 |
> |
raycont(&sr); |
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rayparticipate(&sr); |
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if (trace != NULL) |
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(*trace)(&sr); /* trace execution */ |
| 381 |
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int nsamps; |
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RAY sr; |
| 383 |
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SRCINDEX si; |
| 384 |
< |
double t, lastt, d; |
| 385 |
< |
COLOR cumval, ctmp; |
| 384 |
> |
double t, d; |
| 385 |
> |
double re, ge, be; |
| 386 |
> |
COLOR cvext; |
| 387 |
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int i, j; |
| 388 |
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|
| 389 |
< |
if (r->slights == NULL || r->slights[0] == 0 || r->gecc >= 1.-FTINY) |
| 389 |
> |
if (r->slights == NULL || r->slights[0] == 0 |
| 390 |
> |
|| r->gecc >= 1.-FTINY || r->rot >= FHUGE) |
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return; |
| 392 |
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if (ssampdist <= FTINY || (nsamps = r->rot/ssampdist + .5) < 1) |
| 393 |
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nsamps = 1; |
| 394 |
+ |
#if MAXSSAMP |
| 395 |
+ |
else if (nsamps > MAXSSAMP) |
| 396 |
+ |
nsamps = MAXSSAMP; |
| 397 |
+ |
#endif |
| 398 |
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oldsampndx = samplendx; |
| 399 |
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samplendx = random()&0x7fff; /* randomize */ |
| 400 |
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for (i = r->slights[0]; i > 0; i--) { /* for each source */ |
| 401 |
< |
setcolor(cumval, 0., 0., 0.); |
| 393 |
< |
lastt = r->rot; |
| 394 |
< |
for (j = nsamps; j-- > 0; ) { /* for each sample position */ |
| 401 |
> |
for (j = 0; j < nsamps; j++) { /* for each sample position */ |
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samplendx++; |
| 403 |
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t = r->rot * (j+frandom())/nsamps; |
| 404 |
+ |
/* extinction */ |
| 405 |
+ |
re = t*colval(r->cext,RED); |
| 406 |
+ |
ge = t*colval(r->cext,GRN); |
| 407 |
+ |
be = t*colval(r->cext,BLU); |
| 408 |
+ |
setcolor(cvext, re > 92. ? 0. : exp(-re), |
| 409 |
+ |
ge > 92. ? 0. : exp(-ge), |
| 410 |
+ |
be > 92. ? 0. : exp(-be)); |
| 411 |
+ |
if (intens(cvext) <= FTINY) |
| 412 |
+ |
break; /* too far away */ |
| 413 |
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sr.rorg[0] = r->rorg[0] + r->rdir[0]*t; |
| 414 |
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sr.rorg[1] = r->rorg[1] + r->rdir[1]*t; |
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sr.rorg[2] = r->rorg[2] + r->rdir[2]*t; |
| 421 |
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sr.rsrc != r->slights[i]) |
| 422 |
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continue; /* no path */ |
| 423 |
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copycolor(sr.cext, r->cext); |
| 424 |
< |
sr.albedo = r->albedo; |
| 424 |
> |
copycolor(sr.albedo, r->albedo); |
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sr.gecc = r->gecc; |
| 426 |
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rayvalue(&sr); /* eval. source ray */ |
| 427 |
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if (bright(sr.rcol) <= FTINY) |
| 428 |
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continue; |
| 413 |
– |
/* compute fall-off */ |
| 414 |
– |
d = lastt - t; |
| 415 |
– |
setcolor(ctmp, 1.-d*colval(r->cext,RED), |
| 416 |
– |
1.-d*colval(r->cext,GRN), |
| 417 |
– |
1.-d*colval(r->cext,BLU)); |
| 418 |
– |
multcolor(cumval, ctmp); |
| 419 |
– |
lastt = t; |
| 429 |
|
if (r->gecc <= FTINY) /* compute P(theta) */ |
| 430 |
|
d = 1.; |
| 431 |
|
else { |
| 432 |
|
d = DOT(r->rdir, sr.rdir); |
| 433 |
< |
d = sqrt(1. + r->gecc*r->gecc - 2.*r->gecc*d); |
| 434 |
< |
d = (1. - r->gecc*r->gecc) / (d*d*d); |
| 433 |
> |
d = 1. + r->gecc*r->gecc - 2.*r->gecc*d; |
| 434 |
> |
d = (1. - r->gecc*r->gecc) / (d*sqrt(d)); |
| 435 |
|
} |
| 436 |
|
/* other factors */ |
| 437 |
< |
d *= si.dom * r->albedo * r->rot / (4.*PI*nsamps); |
| 437 |
> |
d *= si.dom * r->rot / (4.*PI*nsamps); |
| 438 |
|
multcolor(sr.rcol, r->cext); |
| 439 |
+ |
multcolor(sr.rcol, r->albedo); |
| 440 |
|
scalecolor(sr.rcol, d); |
| 441 |
< |
addcolor(cumval, sr.rcol); |
| 441 |
> |
multcolor(sr.rcol, cvext); |
| 442 |
> |
addcolor(r->rcol, sr.rcol); /* add it in */ |
| 443 |
|
} |
| 433 |
– |
/* final fall-off */ |
| 434 |
– |
setcolor(ctmp, 1.-lastt*colval(r->cext,RED), |
| 435 |
– |
1.-lastt*colval(r->cext,GRN), |
| 436 |
– |
1.-lastt*colval(r->cext,BLU)); |
| 437 |
– |
multcolor(cumval, ctmp); |
| 438 |
– |
addcolor(r->rcol, cumval); /* sum into ray result */ |
| 444 |
|
} |
| 445 |
|
samplendx = oldsampndx; |
| 446 |
|
} |
