12 |
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#include "cone.h" |
13 |
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#include "source.h" |
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|
15 |
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#ifndef NBSDFSAMPS |
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#define NBSDFSAMPS 32 /* BSDF resampling count */ |
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#endif |
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|
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COLORV * distarr = NULL; /* distribution array */ |
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int distsiz = 0; |
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COLORV * direct_discount = NULL; /* amount to take off direct */ |
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|
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|
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void |
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newdist( /* allocate & clear distribution array */ |
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int siz |
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d = 5.*FTINY; |
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for (i = 3; i--; ) |
159 |
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sr.rorg[i] += d*nrm[i]; |
160 |
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samplendx++; /* increment sample counter */ |
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if (!srcray(&sr, NULL, &si)) |
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break; /* end of sources */ |
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/* index direction */ |
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/* clean up */ |
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freecone(ob); |
659 |
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return(1); |
660 |
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} |
661 |
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|
662 |
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|
663 |
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void |
664 |
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redistribute( /* pass distarr ray sums through BSDF */ |
665 |
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struct BSDF_data *b, |
666 |
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int nalt, |
667 |
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int nazi, |
668 |
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FVECT u, |
669 |
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FVECT v, |
670 |
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FVECT w, |
671 |
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MAT4 xm |
672 |
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) |
673 |
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{ |
674 |
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int nout = 0; |
675 |
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MAT4 mymat, inmat; |
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COLORV *idist; |
677 |
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COLORV *cp; |
678 |
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FVECT dv; |
679 |
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double wt; |
680 |
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int i, j, k, c, o; |
681 |
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COLOR col, cinc; |
682 |
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/* copy incoming distribution */ |
683 |
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if (b->ninc > distsiz) |
684 |
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error(INTERNAL, "error 1 in redistribute"); |
685 |
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idist = (COLORV *)malloc(sizeof(COLOR)*b->ninc); |
686 |
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if (idist == NULL) |
687 |
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error(SYSTEM, "out of memory in redistribute"); |
688 |
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memcpy(idist, distarr, sizeof(COLOR)*b->ninc); |
689 |
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/* compose direction transform */ |
690 |
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for (i = 3; i--; ) { |
691 |
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mymat[i][0] = u[i]; |
692 |
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mymat[i][1] = v[i]; |
693 |
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mymat[i][2] = w[i]; |
694 |
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mymat[i][3] = 0.; |
695 |
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} |
696 |
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mymat[3][0] = mymat[3][1] = mymat[3][2] = 0.; |
697 |
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mymat[3][3] = 1.; |
698 |
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if (xm != NULL) |
699 |
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multmat4(mymat, xm, mymat); |
700 |
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for (i = 3; i--; ) { /* make sure it's normalized */ |
701 |
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wt = 1./sqrt( mymat[0][i]*mymat[0][i] + |
702 |
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mymat[1][i]*mymat[1][i] + |
703 |
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mymat[2][i]*mymat[2][i] ); |
704 |
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for (j = 3; j--; ) |
705 |
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mymat[j][i] *= wt; |
706 |
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} |
707 |
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if (!invmat4(inmat, mymat)) /* need inverse as well */ |
708 |
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error(INTERNAL, "cannot invert BSDF transform"); |
709 |
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newdist(nalt*nazi); /* resample distribution */ |
710 |
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for (i = b->ninc; i--; ) { |
711 |
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int direct_out = -1; |
712 |
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COLOR cdir; |
713 |
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getBSDF_incvec(dv, b, i); /* compute incident irrad. */ |
714 |
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multv3(dv, dv, mymat); |
715 |
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if (dv[2] < 0.0) { |
716 |
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dv[0] = -dv[0]; dv[1] = -dv[1]; dv[2] = -dv[2]; |
717 |
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direct_out += (direct_discount != NULL); |
718 |
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} |
719 |
+ |
wt = getBSDF_incohm(b, i); |
720 |
+ |
wt *= dv[2]; /* solid_angle*cosine(theta) */ |
721 |
+ |
cp = &idist[3*i]; |
722 |
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copycolor(cinc, cp); |
723 |
+ |
scalecolor(cinc, wt); |
724 |
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if (!direct_out) { /* discount direct contr. */ |
725 |
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cp = &direct_discount[3*i]; |
726 |
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copycolor(cdir, cp); |
727 |
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scalecolor(cdir, -wt); |
728 |
+ |
direct_out = flatindex(dv, nalt, nazi); |
729 |
+ |
} |
730 |
+ |
for (k = nalt; k--; ) /* loop over distribution */ |
731 |
+ |
for (j = nazi; j--; ) { |
732 |
+ |
int rstart = random(); |
733 |
+ |
for (c = NBSDFSAMPS; c--; ) { |
734 |
+ |
double sp[2]; |
735 |
+ |
multisamp(sp, 2, urand(rstart+c)); |
736 |
+ |
flatdir(dv, (k + sp[0])/nalt, |
737 |
+ |
(j + .5 - sp[1])/nazi); |
738 |
+ |
multv3(dv, dv, inmat); |
739 |
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/* evaluate BSDF @ outgoing */ |
740 |
+ |
o = getBSDF_outndx(b, dv); |
741 |
+ |
if (o < 0) { |
742 |
+ |
nout++; |
743 |
+ |
continue; |
744 |
+ |
} |
745 |
+ |
wt = BSDF_value(b, i, o) * (1./NBSDFSAMPS); |
746 |
+ |
copycolor(col, cinc); |
747 |
+ |
o = k*nazi + j; |
748 |
+ |
if (o == direct_out) |
749 |
+ |
addcolor(col, cdir); /* minus direct */ |
750 |
+ |
scalecolor(col, wt); |
751 |
+ |
cp = &distarr[3*o]; |
752 |
+ |
addcolor(cp, col); /* sum into distribution */ |
753 |
+ |
} |
754 |
+ |
} |
755 |
+ |
} |
756 |
+ |
free(idist); /* free temp space */ |
757 |
+ |
if (nout) { |
758 |
+ |
sprintf(errmsg, "missing %.1f%% of BSDF directions", |
759 |
+ |
100.*nout/(b->ninc*nalt*nazi*NBSDFSAMPS)); |
760 |
+ |
error(WARNING, errmsg); |
761 |
+ |
} |
762 |
|
} |