| 381 |
|
int nsamps; |
| 382 |
|
RAY sr; |
| 383 |
|
SRCINDEX si; |
| 384 |
< |
double t, lastt, d; |
| 385 |
< |
COLOR cumval, ctmp; |
| 384 |
> |
double t, d; |
| 385 |
> |
double re, ge, be; |
| 386 |
> |
COLOR cvext; |
| 387 |
|
int i, j; |
| 388 |
|
|
| 389 |
|
if (r->slights == NULL || r->slights[0] == 0 |
| 398 |
|
oldsampndx = samplendx; |
| 399 |
|
samplendx = random()&0x7fff; /* randomize */ |
| 400 |
|
for (i = r->slights[0]; i > 0; i--) { /* for each source */ |
| 401 |
< |
setcolor(cumval, 0., 0., 0.); |
| 401 |
< |
lastt = r->rot; |
| 402 |
< |
for (j = nsamps; j-- > 0; ) { /* for each sample position */ |
| 401 |
> |
for (j = 0; j < nsamps; j++) { /* for each sample position */ |
| 402 |
|
samplendx++; |
| 403 |
|
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 |
|
sr.rorg[0] = r->rorg[0] + r->rdir[0]*t; |
| 414 |
|
sr.rorg[1] = r->rorg[1] + r->rdir[1]*t; |
| 415 |
|
sr.rorg[2] = r->rorg[2] + r->rdir[2]*t; |
| 426 |
|
rayvalue(&sr); /* eval. source ray */ |
| 427 |
|
if (bright(sr.rcol) <= FTINY) |
| 428 |
|
continue; |
| 421 |
– |
/* compute fall-off */ |
| 422 |
– |
d = lastt - t; |
| 423 |
– |
setcolor(ctmp, 1.-d*colval(r->cext,RED), |
| 424 |
– |
1.-d*colval(r->cext,GRN), |
| 425 |
– |
1.-d*colval(r->cext,BLU)); |
| 426 |
– |
multcolor(cumval, ctmp); |
| 427 |
– |
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->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 |
|
} |
| 442 |
– |
/* final fall-off */ |
| 443 |
– |
setcolor(ctmp, 1.-lastt*colval(r->cext,RED), |
| 444 |
– |
1.-lastt*colval(r->cext,GRN), |
| 445 |
– |
1.-lastt*colval(r->cext,BLU)); |
| 446 |
– |
multcolor(cumval, ctmp); |
| 447 |
– |
addcolor(r->rcol, cumval); /* sum into ray result */ |
| 444 |
|
} |
| 445 |
|
samplendx = oldsampndx; |
| 446 |
|
} |
