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#include "cone.h" |
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#include "source.h" |
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|
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#ifndef NBSDFSAMPS |
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#define NBSDFSAMPS 256 /* 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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} |
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|
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|
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static void |
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new_discount() /* allocate space for direct contrib. record */ |
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{ |
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if (distsiz <= 0) |
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return; |
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direct_discount = (COLORV *)calloc(distsiz, sizeof(COLOR)); |
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if (direct_discount == NULL) |
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error(SYSTEM, "out of memory in new_discount"); |
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} |
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|
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|
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static void |
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done_discount() /* clear off direct contrib. record */ |
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{ |
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if (direct_discount == NULL) |
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return; |
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free((void *)direct_discount); |
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direct_discount = NULL; |
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} |
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|
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|
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int |
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process_ray( /* process a ray result or report error */ |
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RAY *r, |
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multcolor(r->rcol, r->rcoef); /* in case it's a source ray */ |
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colp = &distarr[r->rno * 3]; |
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addcolor(colp, r->rcol); |
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if (r->rsrc >= 0 && /* remember source contrib. */ |
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direct_discount != NULL) { |
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colp = &direct_discount[r->rno * 3]; |
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addcolor(colp, r->rcol); |
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} |
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return(1); |
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} |
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|
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d = 5.*FTINY; |
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for (i = 3; i--; ) |
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sr.rorg[i] += d*nrm[i]; |
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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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if (i < 0) |
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continue; /* must not be important */ |
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sr.rno = i; |
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d = getBSDF_incrad(il->sd, i); |
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d = 1.0/(PI*d*d); |
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d = 1.0/getBSDF_incohm(il->sd, i); |
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} else { |
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if (v[2] >= -FTINY) |
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continue; /* only sample transmission */ |
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d = 1.0 - v[2]*v[2]; |
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i = d*nalt; |
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d = atan2(-v[1], -v[0])/(2.*PI); |
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if (d < 0.0) d += 1.0; |
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j = d*nazi + 0.5; |
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if (j >= nazi) j = 0; |
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sr.rno = i*nazi + j; |
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d = nalt*nazi/PI; |
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v[0] = -v[0]; v[1] = -v[1]; v[2] = -v[2]; |
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sr.rno = flatindex(v, nalt, nazi); |
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d = nalt*nazi*(1./PI) * v[2]; |
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} |
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d *= si.dom; /* solid angle correction */ |
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scalecolor(sr.rcoef, d); |
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dv[2] = sqrt(1. - alt); |
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} |
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|
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int |
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flatindex( /* compute index for hemispherical direction */ |
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FVECT dv, |
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int nalt, |
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int nazi |
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) |
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{ |
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double d; |
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int i, j; |
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|
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d = 1.0 - dv[2]*dv[2]; |
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i = d*nalt; |
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d = atan2(dv[1], dv[0]) * (0.5/PI); |
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if (d < 0.0) d += 1.0; |
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j = d*nazi + 0.5; |
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if (j >= nazi) j = 0; |
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return(i*nazi + j); |
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} |
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|
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|
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int |
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my_default( /* default illum action */ |
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OBJREC *ob, |
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raysamp(dim[1], org, dir); |
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} |
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/* add in direct component? */ |
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if (!directvis && il->flags & IL_LIGHT) { |
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if (!directvis && (il->flags & IL_LIGHT || il->sd != NULL)) { |
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MAT4 ixfm; |
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if (il->sd == NULL) { |
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for (i = 3; i--; ) { |
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} |
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ixfm[3][0] = ixfm[3][1] = ixfm[3][2] = 0.; |
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ixfm[3][3] = 1.; |
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} else if (!invmat4(ixfm, xfm)) |
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objerror(ob, INTERNAL, "cannot invert BSDF transform"); |
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} else { |
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if (!invmat4(ixfm, xfm)) |
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objerror(ob, INTERNAL, |
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"cannot invert BSDF transform"); |
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if (!(il->flags & IL_LIGHT)) |
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new_discount(); |
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} |
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dim[0] = random(); |
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nallow = 10*il->nsamps; |
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for (i = 0; i < il->nsamps; i++) { |
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nalt = sqrt(il->sd->nout/PI) + .5; |
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nazi = PI*nalt + .5; |
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redistribute(il->sd, nalt, nazi, u, v, fa->norm, xfm); |
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done_discount(); |
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if (!il->sampdens) |
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il->sampdens = nalt*nazi/PI + .999; |
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} |
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/* write out the face and its distribution */ |
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if (average(il, distarr, n)) { |
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raysamp(dim[1], org, dir); |
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} |
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/* add in direct component? */ |
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if (!directvis && il->flags & IL_LIGHT) { |
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if (!directvis && (il->flags & IL_LIGHT || il->sd != NULL)) { |
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MAT4 ixfm; |
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if (il->sd == NULL) { |
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for (i = 3; i--; ) { |
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} |
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ixfm[3][0] = ixfm[3][1] = ixfm[3][2] = 0.; |
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ixfm[3][3] = 1.; |
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} else if (!invmat4(ixfm, xfm)) |
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objerror(ob, INTERNAL, "cannot invert BSDF transform"); |
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} else { |
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if (!invmat4(ixfm, xfm)) |
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objerror(ob, INTERNAL, |
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"cannot invert BSDF transform"); |
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if (!(il->flags & IL_LIGHT)) |
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new_discount(); |
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} |
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dim[0] = random(); |
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for (i = 0; i < il->nsamps; i++) { |
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/* randomize location */ |
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nalt = sqrt(il->sd->nout/PI) + .5; |
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nazi = PI*nalt + .5; |
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redistribute(il->sd, nalt, nazi, u, v, co->ad, xfm); |
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done_discount(); |
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if (!il->sampdens) |
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il->sampdens = nalt*nazi/PI + .999; |
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} |
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/* write out the ring and its distribution */ |
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if (average(il, distarr, n)) { |
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/* clean up */ |
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freecone(ob); |
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return(1); |
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} |
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|
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|
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void |
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redistribute( /* pass distarr ray sums through BSDF */ |
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struct BSDF_data *b, |
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int nalt, |
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int nazi, |
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FVECT u, |
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FVECT v, |
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FVECT w, |
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MAT4 xm |
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) |
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{ |
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int nout = 0; |
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MAT4 mymat, inmat; |
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COLORV *idist; |
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COLORV *cp; |
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FVECT dv; |
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double wt; |
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int i, j, k, c, o; |
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COLOR col, cinc; |
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/* copy incoming distribution */ |
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if (b->ninc > distsiz) |
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error(INTERNAL, "error 1 in redistribute"); |
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idist = (COLORV *)malloc(sizeof(COLOR)*b->ninc); |
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if (idist == NULL) |
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error(SYSTEM, "out of memory in redistribute"); |
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memcpy(idist, distarr, sizeof(COLOR)*b->ninc); |
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/* compose direction transform */ |
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for (i = 3; i--; ) { |
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mymat[i][0] = u[i]; |
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mymat[i][1] = v[i]; |
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mymat[i][2] = w[i]; |
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mymat[i][3] = 0.; |
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} |
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mymat[3][0] = mymat[3][1] = mymat[3][2] = 0.; |
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mymat[3][3] = 1.; |
698 |
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if (xm != NULL) |
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multmat4(mymat, xm, mymat); |
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for (i = 3; i--; ) { /* make sure it's normalized */ |
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wt = 1./sqrt( mymat[0][i]*mymat[0][i] + |
702 |
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mymat[1][i]*mymat[1][i] + |
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mymat[2][i]*mymat[2][i] ); |
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for (j = 3; j--; ) |
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mymat[j][i] *= wt; |
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} |
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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--; ) { |
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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. */ |
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multv3(dv, dv, mymat); |
715 |
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if (dv[2] < 0.0) { |
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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); |
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} |
719 |
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wt = getBSDF_incohm(b, i); |
720 |
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wt *= dv[2]; /* solid_angle*cosine(theta) */ |
721 |
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cp = &idist[3*i]; |
722 |
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copycolor(cinc, cp); |
723 |
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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 |
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if (b->nout != b->ninc) |
729 |
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direct_out = flatindex(dv, nalt, nazi); |
730 |
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else |
731 |
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direct_out = i; /* assumes dist. mirroring */ |
732 |
+ |
} |
733 |
+ |
for (k = nalt; k--; ) /* loop over distribution */ |
734 |
+ |
for (j = nazi; j--; ) { |
735 |
+ |
int rstart = random(); |
736 |
+ |
for (c = NBSDFSAMPS; c--; ) { |
737 |
+ |
double sp[2]; |
738 |
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multisamp(sp, 2, urand(rstart+c)); |
739 |
+ |
flatdir(dv, (k + sp[0])/nalt, |
740 |
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(j + .5 - sp[1])/nazi); |
741 |
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multv3(dv, dv, inmat); |
742 |
+ |
/* evaluate BSDF @ outgoing */ |
743 |
+ |
o = getBSDF_outndx(b, dv); |
744 |
+ |
if (o < 0) { |
745 |
+ |
nout++; |
746 |
+ |
continue; |
747 |
+ |
} |
748 |
+ |
wt = BSDF_value(b, i, o) * (1./NBSDFSAMPS); |
749 |
+ |
copycolor(col, cinc); |
750 |
+ |
if (b->nout != b->ninc) |
751 |
+ |
o = k*nazi + j; |
752 |
+ |
if (o == direct_out) |
753 |
+ |
addcolor(col, cdir); /* minus direct */ |
754 |
+ |
scalecolor(col, wt); |
755 |
+ |
cp = &distarr[3*o]; |
756 |
+ |
addcolor(cp, col); /* sum into distribution */ |
757 |
+ |
} |
758 |
+ |
} |
759 |
+ |
} |
760 |
+ |
free(idist); /* free temp space */ |
761 |
+ |
if (nout) { |
762 |
+ |
sprintf(errmsg, "missing %.1f%% of BSDF directions", |
763 |
+ |
100.*nout/(b->ninc*nalt*nazi*NBSDFSAMPS)); |
764 |
+ |
error(WARNING, errmsg); |
765 |
+ |
} |
766 |
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} |