411 |
|
) |
412 |
|
{ |
413 |
|
static int warnedPM = 0; |
414 |
+ |
double re, ge, be; |
415 |
+ |
SCOLOR ce; |
416 |
|
|
417 |
|
setscolor(rc, 1., 1., 1.); |
418 |
+ |
re = ge = be = 0.; |
419 |
|
|
420 |
|
while (r != NULL && r->crtype&flags) { |
421 |
+ |
/* include this ray coefficient */ |
422 |
|
smultscolor(rc, r->rcoef); |
423 |
< |
/* check for participating medium */ |
420 |
< |
if (bright(r->cext) > FTINY) { |
421 |
< |
double re = r->rot*colval(r->cext,RED), |
422 |
< |
ge = r->rot*colval(r->cext,GRN), |
423 |
< |
be = r->rot*colval(r->cext,BLU); |
424 |
< |
SCOLOR ce; |
425 |
< |
setscolor(ce, re<=FTINY ? 1. : re>92. ? 0. : exp(-re), |
426 |
< |
ge<=FTINY ? 1. : ge>92. ? 0. : exp(-ge), |
427 |
< |
be<=FTINY ? 1. : be>92. ? 0. : exp(-be)); |
428 |
< |
smultscolor(rc, ce); |
429 |
< |
} |
423 |
> |
/* check participating medium */ |
424 |
|
if (!warnedPM && bright(r->albedo) > FTINY) { |
425 |
|
error(WARNING, |
426 |
|
"ray contribution calculation does not support participating media"); |
427 |
|
warnedPM++; |
428 |
|
} |
429 |
+ |
/* sum PM extinction */ |
430 |
+ |
re += r->rot*colval(r->cext,RED); |
431 |
+ |
ge += r->rot*colval(r->cext,GRN); |
432 |
+ |
be += r->rot*colval(r->cext,BLU); |
433 |
+ |
/* descend the tree */ |
434 |
|
r = r->parent; |
435 |
|
} |
436 |
+ |
/* cumulative extinction */ |
437 |
+ |
setscolor(ce, re<=FTINY ? 1. : re>92. ? 0. : exp(-re), |
438 |
+ |
ge<=FTINY ? 1. : ge>92. ? 0. : exp(-ge), |
439 |
+ |
be<=FTINY ? 1. : be>92. ? 0. : exp(-be)); |
440 |
+ |
smultscolor(rc, ce); |
441 |
|
} |
442 |
|
|
443 |
|
|