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extern double ssampdist; /* scatter sampling distance */ |
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#ifndef MAXSSAMP |
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#define MAXSSAMP 16 /* maximum samples per ray */ |
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#endif |
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|
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/* |
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* Structures used by direct() |
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*/ |
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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 */ |
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if (!raycont(&sr)) |
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objerror(sr.ro, USER, "material not found"); |
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raycont(&sr); |
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rayparticipate(&sr); |
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if (trace != NULL) |
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(*trace)(&sr); /* trace execution */ |
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srcscatter(r) /* compute source scattering into ray */ |
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register RAY *r; |
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{ |
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int oldsampndx; |
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int nsamps; |
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RAY sr; |
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SRCINDEX si; |
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double t, lastt, d; |
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COLOR cumval, ctmp; |
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double t, d; |
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double re, ge, be; |
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COLOR cvext; |
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int i, j; |
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if (r->slights == NULL || r->slights[0] == 0 || r->gecc >= 1.-FTINY) |
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if (r->slights == NULL || r->slights[0] == 0 |
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|| r->gecc >= 1.-FTINY || r->rot >= FHUGE) |
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return; |
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if (ssampdist <= FTINY || (nsamps = r->rot/ssampdist + .5) < 1) |
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nsamps = 1; |
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initsrcindex(&si); |
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> |
#if MAXSSAMP |
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else if (nsamps > MAXSSAMP) |
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nsamps = MAXSSAMP; |
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#endif |
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oldsampndx = samplendx; |
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samplendx = random()&0x7fff; /* randomize */ |
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for (i = r->slights[0]; i > 0; i--) { /* for each source */ |
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setcolor(cumval, 0., 0., 0.); |
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lastt = r->rot; |
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for (j = nsamps; j-- > 0; ) { /* for each sample position */ |
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for (j = 0; j < nsamps; j++) { /* for each sample position */ |
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samplendx++; |
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t = r->rot * (j+frandom())/nsamps; |
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/* extinction */ |
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re = t*colval(r->cext,RED); |
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ge = t*colval(r->cext,GRN); |
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be = t*colval(r->cext,BLU); |
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setcolor(cvext, re > 92. ? 0. : exp(-re), |
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ge > 92. ? 0. : exp(-ge), |
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be > 92. ? 0. : exp(-be)); |
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if (intens(cvext) <= FTINY) |
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break; /* too far away */ |
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sr.rorg[0] = r->rorg[0] + r->rdir[0]*t; |
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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; |
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sr.rmax = 0.; |
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< |
/* sample ray to this source */ |
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< |
if (si.sp >= si.np-1 || !srcray(&sr, NULL, &si) || |
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< |
sr.rsrc != r->slights[i]) { |
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< |
si.sn = r->slights[i]-1; /* reset */ |
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< |
si.np = 0; |
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< |
if (!srcray(&sr, NULL, &si) || |
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< |
sr.rsrc != r->slights[i]) |
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< |
continue; /* no path */ |
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< |
} |
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> |
initsrcindex(&si); /* sample ray to this source */ |
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> |
si.sn = r->slights[i]; |
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> |
nopart(&si, &sr); |
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> |
if (!srcray(&sr, NULL, &si) || |
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> |
sr.rsrc != r->slights[i]) |
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> |
continue; /* no path */ |
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copycolor(sr.cext, r->cext); |
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< |
sr.albedo = r->albedo; |
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> |
copycolor(sr.albedo, r->albedo); |
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sr.gecc = r->gecc; |
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+ |
sr.slights = r->slights; |
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rayvalue(&sr); /* eval. source ray */ |
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if (bright(sr.rcol) <= FTINY) |
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continue; |
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/* compute fall-off */ |
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d = lastt - t; |
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setcolor(ctmp, 1.-d*colval(r->cext,RED), |
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– |
1.-d*colval(r->cext,GRN), |
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– |
1.-d*colval(r->cext,BLU)); |
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– |
multcolor(cumval, ctmp); |
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– |
lastt = t; |
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if (r->gecc <= FTINY) /* compute P(theta) */ |
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d = 1.; |
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else { |
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d = DOT(r->rdir, sr.rdir); |
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< |
d = sqrt(1. + r->gecc*r->gecc - 2.*r->gecc*d); |
| 435 |
< |
d = (1. - r->gecc*r->gecc) / (d*d*d); |
| 434 |
> |
d = 1. + r->gecc*r->gecc - 2.*r->gecc*d; |
| 435 |
> |
d = (1. - r->gecc*r->gecc) / (d*sqrt(d)); |
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} |
| 437 |
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/* other factors */ |
| 438 |
< |
d *= si.dom * r->albedo * r->rot / (4.*PI*nsamps); |
| 438 |
> |
d *= si.dom * r->rot / (4.*PI*nsamps); |
| 439 |
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multcolor(sr.rcol, r->cext); |
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+ |
multcolor(sr.rcol, r->albedo); |
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scalecolor(sr.rcol, d); |
| 442 |
< |
addcolor(cumval, sr.rcol); |
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> |
multcolor(sr.rcol, cvext); |
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> |
addcolor(r->rcol, sr.rcol); /* add it in */ |
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} |
| 434 |
– |
/* final fall-off */ |
| 435 |
– |
setcolor(ctmp, 1.-lastt*colval(r->cext,RED), |
| 436 |
– |
1.-lastt*colval(r->cext,GRN), |
| 437 |
– |
1.-lastt*colval(r->cext,BLU)); |
| 438 |
– |
multcolor(cumval, ctmp); |
| 439 |
– |
addcolor(r->rcol, cumval); /* sum into ray result */ |
| 445 |
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} |
| 446 |
+ |
samplendx = oldsampndx; |
| 447 |
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} |
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