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#include "copyright.h" |
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|
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#include "ray.h" |
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#include "otypes.h" |
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#include "ambient.h" |
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#include "source.h" |
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#include "func.h" |
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#include "pmapmat.h" |
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|
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/* |
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< |
* Arguments to this material include optional diffuse colors. |
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> |
* Arguments to this material include optional diffuse colors. |
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* String arguments include the BSDF and function files. |
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< |
* A non-zero thickness causes the strange but useful behavior |
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> |
* For the MAT_BSDF type, a non-zero thickness causes the useful behavior |
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* of translating transmitted rays this distance beneath the surface |
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* (opposite the surface normal) to bypass any intervening geometry. |
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* Translation only affects scattered, non-source-directed samples. |
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* hides geometry in front of the surface when rays hit from behind, |
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* and applies only the transmission and backside reflectance properties. |
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* Reflection is ignored on the hidden side, as those rays pass through. |
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< |
* When thickness is set to zero, shadow rays will be blocked unless |
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< |
* a BTDF has a strong "through" component in the source direction. |
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> |
* For the MAT_SBSDF type, we check for a strong "through" component. |
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> |
* Such a component will cause direct rays to pass through unscattered. |
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* A separate test prevents over-counting by dropping samples that are |
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* too close to this "through" direction. BSDFs with such a through direction |
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* will also have a view component, meaning they are somewhat see-through. |
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* A MAT_BSDF type with zero thickness behaves the same as a MAT_SBSDF |
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* type with no strong through component. |
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* The "up" vector for the BSDF is given by three variables, defined |
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* (along with the thickness) by the named function file, or '.' if none. |
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* Together with the surface normal, this defines the local coordinate |
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* not multiplied. However, patterns affect this material as a multiplier |
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* on everything except non-diffuse reflection. |
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* |
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* Arguments for MAT_SBSDF are: |
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* 5+ BSDFfile ux uy uz funcfile transform |
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* 0 |
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* 0|3|6|9 rdf gdf bdf |
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* rdb gdb bdb |
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* rdt gdt bdt |
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* |
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* Arguments for MAT_BSDF are: |
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* 6+ thick BSDFfile ux uy uz funcfile transform |
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* 0 |
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RREAL toloc[3][3]; /* world to local BSDF coords */ |
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RREAL fromloc[3][3]; /* local BSDF coords to world */ |
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double thick; /* surface thickness */ |
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< |
COLOR cthru; /* "through" component multiplier */ |
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> |
COLOR cthru; /* "through" component for MAT_SBSDF */ |
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SDData *sd; /* loaded BSDF data */ |
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COLOR rdiff; /* diffuse reflection */ |
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COLOR runsamp; /* BSDF hemispherical reflection */ |
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|
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#define cvt_sdcolor(cv, svp) ccy2rgb(&(svp)->spec, (svp)->cieY, cv) |
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|
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/* Compute "through" component color */ |
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> |
/* Compute "through" component color for MAT_SBSDF */ |
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static void |
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compute_through(BSDFDAT *ndp) |
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{ |
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int i; |
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SDError ec; |
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|
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setcolor(ndp->cthru, 0, 0, 0); /* starting assumption */ |
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– |
|
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if (ndp->pr->rod > 0) |
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dfp = (ndp->sd->tf != NULL) ? ndp->sd->tf : ndp->sd->tb; |
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else |
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if ((vsrc[2] > 0) ^ (ndp->vray[2] > 0) && bright(ndp->cthru) > FTINY) { |
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double dx = vsrc[0] + ndp->vray[0]; |
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double dy = vsrc[1] + ndp->vray[1]; |
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< |
if (dx*dx + dy*dy <= (1.5*4./PI)*(omega + tomega + |
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> |
if (dx*dx + dy*dy <= (2.5*4./PI)*(omega + tomega + |
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2.*sqrt(omega*tomega))) |
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return(0); |
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} |
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int |
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m_bsdf(OBJREC *m, RAY *r) |
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{ |
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int hasthick = (m->otype == MAT_BSDF); |
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int hitfront; |
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COLOR ctmp; |
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SDError ec; |
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MFUNC *mf; |
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BSDFDAT nd; |
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/* check arguments */ |
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< |
if ((m->oargs.nsargs < 6) | (m->oargs.nfargs > 9) | |
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> |
if ((m->oargs.nsargs < hasthick+5) | (m->oargs.nfargs > 9) | |
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(m->oargs.nfargs % 3)) |
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objerror(m, USER, "bad # arguments"); |
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/* record surface struck */ |
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hitfront = (r->rod > 0); |
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/* load cal file */ |
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< |
mf = getfunc(m, 5, 0x1d, 1); |
| 606 |
> |
mf = hasthick ? getfunc(m, 5, 0x1d, 1) |
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> |
: getfunc(m, 4, 0xe, 1) ; |
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setfunc(m, r); |
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< |
/* get thickness */ |
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< |
nd.thick = evalue(mf->ep[0]); |
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< |
if ((-FTINY <= nd.thick) & (nd.thick <= FTINY)) |
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< |
nd.thick = 0; |
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> |
nd.thick = 0; /* set thickness */ |
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> |
if (hasthick) { |
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> |
nd.thick = evalue(mf->ep[0]); |
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> |
if ((-FTINY <= nd.thick) & (nd.thick <= FTINY)) |
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> |
nd.thick = 0; |
| 614 |
> |
} |
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/* check backface visibility */ |
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if (!hitfront & !backvis) { |
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raytrans(r); |
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nd.mp = m; |
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nd.pr = r; |
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/* get BSDF data */ |
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< |
nd.sd = loadBSDF(m->oargs.sarg[1]); |
| 630 |
> |
nd.sd = loadBSDF(m->oargs.sarg[hasthick]); |
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/* early shadow check */ |
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if (r->crtype & SHADOW && (nd.sd->tf == NULL) & (nd.sd->tb == NULL)) |
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return(1); |
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multcolor(nd.rdiff, r->pcol); |
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multcolor(nd.tdiff, r->pcol); |
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/* get up vector */ |
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< |
upvec[0] = evalue(mf->ep[1]); |
| 667 |
< |
upvec[1] = evalue(mf->ep[2]); |
| 668 |
< |
upvec[2] = evalue(mf->ep[3]); |
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> |
upvec[0] = evalue(mf->ep[hasthick+0]); |
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> |
upvec[1] = evalue(mf->ep[hasthick+1]); |
| 668 |
> |
upvec[2] = evalue(mf->ep[hasthick+2]); |
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/* return to world coords */ |
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if (mf->fxp != &unitxf) { |
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multv3(upvec, upvec, mf->fxp->xfm); |
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objerror(m, WARNING, "Illegal orientation vector"); |
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return(1); |
| 690 |
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} |
| 691 |
< |
compute_through(&nd); /* compute through component */ |
| 692 |
< |
if (r->crtype & SHADOW) { |
| 693 |
< |
RAY tr; /* attempt to pass shadow ray */ |
| 694 |
< |
if (rayorigin(&tr, TRANS, r, nd.cthru) < 0) |
| 695 |
< |
return(1); /* no through component */ |
| 696 |
< |
VCOPY(tr.rdir, r->rdir); |
| 697 |
< |
rayvalue(&tr); /* transmit with scaling */ |
| 698 |
< |
multcolor(tr.rcol, tr.rcoef); |
| 699 |
< |
copycolor(r->rcol, tr.rcol); |
| 700 |
< |
return(1); /* we're done */ |
| 691 |
> |
setcolor(nd.cthru, 0, 0, 0); /* consider through component */ |
| 692 |
> |
if (m->otype == MAT_SBSDF) { |
| 693 |
> |
compute_through(&nd); |
| 694 |
> |
if (r->crtype & SHADOW) { |
| 695 |
> |
RAY tr; /* attempt to pass shadow ray */ |
| 696 |
> |
if (rayorigin(&tr, TRANS, r, nd.cthru) < 0) |
| 697 |
> |
return(1); /* no through component */ |
| 698 |
> |
VCOPY(tr.rdir, r->rdir); |
| 699 |
> |
rayvalue(&tr); /* transmit with scaling */ |
| 700 |
> |
multcolor(tr.rcol, tr.rcoef); |
| 701 |
> |
copycolor(r->rcol, tr.rcol); |
| 702 |
> |
return(1); /* we're done */ |
| 703 |
> |
} |
| 704 |
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} |
| 705 |
|
ec = SDinvXform(nd.fromloc, nd.toloc); |
| 706 |
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if (!ec) /* determine BSDF resolution */ |
