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/* Copyright (c) 1986 Regents of the University of California */ |
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/* Copyright (c) 1992 Regents of the University of California */ |
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#ifndef lint |
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static char SCCSid[] = "$SunId$ LBL"; |
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* 12/19/85 - added stuff for metals. |
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* 6/26/87 - improved specular model. |
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* 9/28/87 - added model for translucent materials. |
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* Later changes described in delta comments. |
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*/ |
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#include "ray.h" |
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|
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– |
#include "source.h" |
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|
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#include "otypes.h" |
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|
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#include "random.h" |
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|
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extern double specthresh; /* specular sampling threshold */ |
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extern double specjitter; /* specular sampling jitter */ |
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|
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/* |
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* This routine uses portions of the reflection |
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* model described by Cook and Torrance. |
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|
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#define BSPEC(m) (6.0) /* specularity parameter b */ |
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|
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/* specularity flags */ |
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#define SP_REFL 01 /* has reflected specular component */ |
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#define SP_TRAN 02 /* has transmitted specular */ |
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#define SP_PURE 010 /* purely specular (zero roughness) */ |
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#define SP_FLAT 020 /* flat reflecting surface */ |
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#define SP_RBLT 040 /* reflection below sample threshold */ |
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#define SP_TBLT 0100 /* transmission below threshold */ |
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|
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m_normal(m, r) /* color a ray which hit something normal */ |
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register OBJREC *m; |
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register RAY *r; |
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{ |
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double exp(); |
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typedef struct { |
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OBJREC *mp; /* material pointer */ |
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> |
short specfl; /* specularity flags, defined above */ |
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COLOR mcolor; /* color of this material */ |
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COLOR scolor; /* color of specular component */ |
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FVECT vrefl; /* vector in direction of reflected ray */ |
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double alpha2; /* roughness squared times 2 */ |
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RAY lr; /* ray to illumination source */ |
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FVECT prdir; /* vector in transmitted direction */ |
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double alpha2; /* roughness squared */ |
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double rdiff, rspec; /* reflected specular, diffuse */ |
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double trans; /* transmissivity */ |
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double tdiff, tspec; /* transmitted specular, diffuse */ |
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FVECT pnorm; /* perturbed surface normal */ |
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double pdot; /* perturbed dot product */ |
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} NORMDAT; /* normal material data */ |
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|
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|
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dirnorm(cval, np, ldir, omega) /* compute source contribution */ |
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COLOR cval; /* returned coefficient */ |
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register NORMDAT *np; /* material data */ |
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FVECT ldir; /* light source direction */ |
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double omega; /* light source size */ |
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{ |
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double ldot; |
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double omega; |
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double dtmp; |
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int i; |
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COLOR ctmp; |
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register int i; |
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|
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if (m->oargs.nfargs != (m->otype == MAT_TRANS ? 7 : 5)) |
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objerror(m, USER, "bad # arguments"); |
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setcolor(cval, 0.0, 0.0, 0.0); |
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|
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ldot = DOT(np->pnorm, ldir); |
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|
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if (ldot < 0.0 ? np->trans <= FTINY : np->trans >= 1.0-FTINY) |
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return; /* wrong side */ |
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|
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if (ldot > FTINY && np->rdiff > FTINY) { |
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/* |
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* Compute and add diffuse reflected component to returned |
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* color. The diffuse reflected component will always be |
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* modified by the color of the material. |
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*/ |
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copycolor(ctmp, np->mcolor); |
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dtmp = ldot * omega * np->rdiff / PI; |
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scalecolor(ctmp, dtmp); |
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addcolor(cval, ctmp); |
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} |
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if (ldot > FTINY && (np->specfl&(SP_REFL|SP_PURE)) == SP_REFL) { |
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/* |
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* Compute specular reflection coefficient using |
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* gaussian distribution model. |
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*/ |
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/* roughness */ |
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dtmp = 2.0*np->alpha2; |
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/* + source if flat */ |
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if (np->specfl & SP_FLAT) |
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dtmp += omega/(2.0*PI); |
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/* gaussian */ |
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dtmp = exp((DOT(np->vrefl,ldir)-1.)/dtmp)/(2.*PI)/dtmp; |
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/* worth using? */ |
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if (dtmp > FTINY) { |
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copycolor(ctmp, np->scolor); |
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dtmp *= omega / np->pdot; |
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scalecolor(ctmp, dtmp); |
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addcolor(cval, ctmp); |
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} |
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} |
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if (ldot < -FTINY && np->tdiff > FTINY) { |
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/* |
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* Compute diffuse transmission. |
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*/ |
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copycolor(ctmp, np->mcolor); |
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dtmp = -ldot * omega * np->tdiff / PI; |
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scalecolor(ctmp, dtmp); |
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addcolor(cval, ctmp); |
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} |
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if (ldot < -FTINY && (np->specfl&(SP_TRAN|SP_PURE)) == SP_TRAN) { |
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/* |
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* Compute specular transmission. Specular transmission |
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* is always modified by material color. |
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*/ |
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/* roughness + source */ |
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dtmp = np->alpha2 + omega/(2.0*PI); |
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/* gaussian */ |
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dtmp = exp((DOT(np->prdir,ldir)-1.)/dtmp)/(2.*PI)/dtmp; |
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/* worth using? */ |
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if (dtmp > FTINY) { |
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copycolor(ctmp, np->mcolor); |
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dtmp *= np->tspec * omega / np->pdot; |
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scalecolor(ctmp, dtmp); |
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addcolor(cval, ctmp); |
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} |
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} |
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} |
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|
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|
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m_normal(m, r) /* color a ray that hit something normal */ |
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register OBJREC *m; |
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register RAY *r; |
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{ |
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NORMDAT nd; |
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double transtest, transdist; |
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double dtmp; |
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COLOR ctmp; |
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register int i; |
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/* easy shadow test */ |
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if (r->crtype & SHADOW && m->otype != MAT_TRANS) |
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return; |
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+ |
|
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if (m->oargs.nfargs != (m->otype == MAT_TRANS ? 7 : 5)) |
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objerror(m, USER, "bad number of arguments"); |
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nd.mp = m; |
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/* get material color */ |
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< |
setcolor(mcolor, m->oargs.farg[0], |
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> |
setcolor(nd.mcolor, m->oargs.farg[0], |
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m->oargs.farg[1], |
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m->oargs.farg[2]); |
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/* get roughness */ |
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< |
alpha2 = m->oargs.farg[4]; |
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< |
alpha2 *= 2.0 * alpha2; |
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> |
nd.specfl = 0; |
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> |
nd.alpha2 = m->oargs.farg[4]; |
| 168 |
> |
if ((nd.alpha2 *= nd.alpha2) <= FTINY) |
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nd.specfl |= SP_PURE; |
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/* reorient if necessary */ |
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if (r->rod < 0.0) |
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flipsurface(r); |
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/* get modifiers */ |
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raytexture(r, m->omod); |
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pdot = raynormal(pnorm, r); /* perturb normal */ |
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multcolor(mcolor, r->pcol); /* modify material color */ |
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> |
nd.pdot = raynormal(nd.pnorm, r); /* perturb normal */ |
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> |
if (nd.pdot < .001) |
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nd.pdot = .001; /* non-zero for dirnorm() */ |
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multcolor(nd.mcolor, r->pcol); /* modify material color */ |
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transtest = 0; |
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/* get specular component */ |
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< |
rspec = m->oargs.farg[3]; |
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< |
|
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< |
if (rspec > FTINY) { /* has specular component */ |
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> |
if ((nd.rspec = m->oargs.farg[3]) > FTINY) { |
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nd.specfl |= SP_REFL; |
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/* compute specular color */ |
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if (m->otype == MAT_METAL) |
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< |
copycolor(scolor, mcolor); |
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> |
copycolor(nd.scolor, nd.mcolor); |
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else |
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< |
setcolor(scolor, 1.0, 1.0, 1.0); |
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< |
scalecolor(scolor, rspec); |
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> |
setcolor(nd.scolor, 1.0, 1.0, 1.0); |
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> |
scalecolor(nd.scolor, nd.rspec); |
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/* improved model */ |
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< |
dtmp = exp(-BSPEC(m)*pdot); |
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> |
dtmp = exp(-BSPEC(m)*nd.pdot); |
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for (i = 0; i < 3; i++) |
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< |
colval(scolor,i) += (1.0-colval(scolor,i))*dtmp; |
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< |
rspec += (1.0-rspec)*dtmp; |
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> |
colval(nd.scolor,i) += (1.0-colval(nd.scolor,i))*dtmp; |
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> |
nd.rspec += (1.0-nd.rspec)*dtmp; |
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> |
/* check threshold */ |
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> |
if (specthresh > FTINY && |
| 196 |
> |
((specthresh >= 1.-FTINY || |
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> |
specthresh + (.1 - .2*urand(8199+samplendx)) |
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> |
> nd.rspec))) |
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> |
nd.specfl |= SP_RBLT; |
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/* compute reflected ray */ |
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for (i = 0; i < 3; i++) |
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< |
vrefl[i] = r->rdir[i] + 2.0*pdot*pnorm[i]; |
| 202 |
> |
nd.vrefl[i] = r->rdir[i] + 2.0*nd.pdot*nd.pnorm[i]; |
| 203 |
> |
if (DOT(nd.vrefl, r->ron) <= FTINY) /* penetration? */ |
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> |
for (i = 0; i < 3; i++) /* safety measure */ |
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> |
nd.vrefl[i] = r->rdir[i] + 2.*r->rod*r->ron[i]; |
| 206 |
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|
| 207 |
< |
if (alpha2 <= FTINY && !(r->crtype & SHADOW)) |
| 208 |
< |
if (rayorigin(&lr, r, REFLECTED, rspec) == 0) { |
| 209 |
< |
VCOPY(lr.rdir, vrefl); |
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> |
if (!(r->crtype & SHADOW) && nd.specfl & SP_PURE) { |
| 208 |
> |
RAY lr; |
| 209 |
> |
if (rayorigin(&lr, r, REFLECTED, nd.rspec) == 0) { |
| 210 |
> |
VCOPY(lr.rdir, nd.vrefl); |
| 211 |
|
rayvalue(&lr); |
| 212 |
< |
multcolor(lr.rcol, scolor); |
| 212 |
> |
multcolor(lr.rcol, nd.scolor); |
| 213 |
|
addcolor(r->rcol, lr.rcol); |
| 214 |
|
} |
| 215 |
+ |
} |
| 216 |
|
} |
| 217 |
< |
|
| 217 |
> |
/* compute transmission */ |
| 218 |
|
if (m->otype == MAT_TRANS) { |
| 219 |
< |
trans = m->oargs.farg[5]*(1.0 - rspec); |
| 220 |
< |
tspec = trans * m->oargs.farg[6]; |
| 221 |
< |
tdiff = trans - tspec; |
| 219 |
> |
nd.trans = m->oargs.farg[5]*(1.0 - nd.rspec); |
| 220 |
> |
nd.tspec = nd.trans * m->oargs.farg[6]; |
| 221 |
> |
nd.tdiff = nd.trans - nd.tspec; |
| 222 |
> |
if (nd.tspec > FTINY) { |
| 223 |
> |
nd.specfl |= SP_TRAN; |
| 224 |
> |
/* check threshold */ |
| 225 |
> |
if (specthresh > FTINY && |
| 226 |
> |
((specthresh >= 1.-FTINY || |
| 227 |
> |
specthresh + |
| 228 |
> |
(.1 - .2*urand(7241+samplendx)) |
| 229 |
> |
> nd.tspec))) |
| 230 |
> |
nd.specfl |= SP_TBLT; |
| 231 |
> |
if (r->crtype & SHADOW || |
| 232 |
> |
DOT(r->pert,r->pert) <= FTINY*FTINY) { |
| 233 |
> |
VCOPY(nd.prdir, r->rdir); |
| 234 |
> |
transtest = 2; |
| 235 |
> |
} else { |
| 236 |
> |
for (i = 0; i < 3; i++) /* perturb */ |
| 237 |
> |
nd.prdir[i] = r->rdir[i] - |
| 238 |
> |
.75*r->pert[i]; |
| 239 |
> |
if (DOT(nd.prdir, r->ron) < -FTINY) |
| 240 |
> |
normalize(nd.prdir); /* OK */ |
| 241 |
> |
else |
| 242 |
> |
VCOPY(nd.prdir, r->rdir); |
| 243 |
> |
} |
| 244 |
> |
} |
| 245 |
|
} else |
| 246 |
< |
tdiff = tspec = trans = 0.0; |
| 246 |
> |
nd.tdiff = nd.tspec = nd.trans = 0.0; |
| 247 |
|
/* transmitted ray */ |
| 248 |
< |
if (tspec > FTINY && alpha2 <= FTINY) |
| 249 |
< |
if (rayorigin(&lr, r, TRANS, tspec) == 0) { |
| 250 |
< |
VCOPY(lr.rdir, r->rdir); |
| 248 |
> |
if ((nd.specfl&(SP_TRAN|SP_PURE)) == (SP_TRAN|SP_PURE)) { |
| 249 |
> |
RAY lr; |
| 250 |
> |
if (rayorigin(&lr, r, TRANS, nd.tspec) == 0) { |
| 251 |
> |
VCOPY(lr.rdir, nd.prdir); |
| 252 |
|
rayvalue(&lr); |
| 253 |
< |
scalecolor(lr.rcol, tspec); |
| 253 |
> |
scalecolor(lr.rcol, nd.tspec); |
| 254 |
> |
multcolor(lr.rcol, nd.mcolor); /* modified by color */ |
| 255 |
|
addcolor(r->rcol, lr.rcol); |
| 256 |
+ |
transtest *= bright(lr.rcol); |
| 257 |
+ |
transdist = r->rot + lr.rt; |
| 258 |
|
} |
| 259 |
+ |
} |
| 260 |
+ |
|
| 261 |
|
if (r->crtype & SHADOW) /* the rest is shadow */ |
| 262 |
|
return; |
| 263 |
|
/* diffuse reflection */ |
| 264 |
< |
rdiff = 1.0 - trans - rspec; |
| 264 |
> |
nd.rdiff = 1.0 - nd.trans - nd.rspec; |
| 265 |
|
|
| 266 |
< |
if (rdiff <= FTINY && tdiff <= FTINY && alpha2 <= FTINY) |
| 267 |
< |
return; /* purely specular */ |
| 266 |
> |
if (nd.specfl & SP_PURE && nd.rdiff <= FTINY && nd.tdiff <= FTINY) |
| 267 |
> |
return; /* 100% pure specular */ |
| 268 |
|
|
| 269 |
< |
if (rdiff > FTINY) { /* ambient from this side */ |
| 269 |
> |
if (r->ro->otype == OBJ_FACE || r->ro->otype == OBJ_RING) |
| 270 |
> |
nd.specfl |= SP_FLAT; |
| 271 |
> |
|
| 272 |
> |
if (nd.specfl & (SP_REFL|SP_TRAN) && !(nd.specfl & SP_PURE)) |
| 273 |
> |
gaussamp(r, &nd); |
| 274 |
> |
|
| 275 |
> |
if (nd.rdiff > FTINY) { /* ambient from this side */ |
| 276 |
|
ambient(ctmp, r); |
| 277 |
< |
if (alpha2 <= FTINY) |
| 278 |
< |
scalecolor(ctmp, rdiff); |
| 277 |
> |
if (nd.specfl & SP_RBLT) |
| 278 |
> |
scalecolor(ctmp, 1.0-nd.trans); |
| 279 |
|
else |
| 280 |
< |
scalecolor(ctmp, 1.0-trans); |
| 281 |
< |
multcolor(ctmp, mcolor); /* modified by material color */ |
| 280 |
> |
scalecolor(ctmp, nd.rdiff); |
| 281 |
> |
multcolor(ctmp, nd.mcolor); /* modified by material color */ |
| 282 |
|
addcolor(r->rcol, ctmp); /* add to returned color */ |
| 283 |
|
} |
| 284 |
< |
if (tdiff > FTINY) { /* ambient from other side */ |
| 284 |
> |
if (nd.tdiff > FTINY) { /* ambient from other side */ |
| 285 |
|
flipsurface(r); |
| 286 |
|
ambient(ctmp, r); |
| 287 |
< |
if (alpha2 <= FTINY) |
| 288 |
< |
scalecolor(ctmp, tdiff); |
| 287 |
> |
if (nd.specfl & SP_TBLT) |
| 288 |
> |
scalecolor(ctmp, nd.trans); |
| 289 |
|
else |
| 290 |
< |
scalecolor(ctmp, trans); |
| 291 |
< |
multcolor(ctmp, mcolor); |
| 290 |
> |
scalecolor(ctmp, nd.tdiff); |
| 291 |
> |
multcolor(ctmp, nd.mcolor); /* modified by color */ |
| 292 |
|
addcolor(r->rcol, ctmp); |
| 293 |
|
flipsurface(r); |
| 294 |
|
} |
| 295 |
< |
|
| 296 |
< |
for (i = 0; i < nsources; i++) { /* add specular and diffuse */ |
| 295 |
> |
/* add direct component */ |
| 296 |
> |
direct(r, dirnorm, &nd); |
| 297 |
> |
/* check distance */ |
| 298 |
> |
if (transtest > bright(r->rcol)) |
| 299 |
> |
r->rt = transdist; |
| 300 |
> |
} |
| 301 |
|
|
| 153 |
– |
if ((omega = srcray(&lr, r, i)) == 0.0) |
| 154 |
– |
continue; /* bad source */ |
| 302 |
|
|
| 303 |
< |
ldot = DOT(pnorm, lr.rdir); |
| 304 |
< |
|
| 305 |
< |
if (ldot < 0.0 ? trans <= FTINY : trans >= 1.0-FTINY) |
| 306 |
< |
continue; /* wrong side */ |
| 307 |
< |
|
| 308 |
< |
rayvalue(&lr); /* compute light ray value */ |
| 309 |
< |
|
| 310 |
< |
if (intens(lr.rcol) <= FTINY) |
| 311 |
< |
continue; /* didn't hit light source */ |
| 312 |
< |
|
| 313 |
< |
if (ldot > FTINY && rdiff > FTINY) { |
| 314 |
< |
/* |
| 315 |
< |
* Compute and add diffuse component to returned color. |
| 316 |
< |
* The diffuse component will always be modified by the |
| 317 |
< |
* color of the material. |
| 318 |
< |
*/ |
| 319 |
< |
copycolor(ctmp, lr.rcol); |
| 320 |
< |
dtmp = ldot * omega * rdiff / PI; |
| 321 |
< |
scalecolor(ctmp, dtmp); |
| 322 |
< |
multcolor(ctmp, mcolor); |
| 323 |
< |
addcolor(r->rcol, ctmp); |
| 324 |
< |
} |
| 325 |
< |
if (ldot > FTINY && rspec > FTINY && alpha2 > FTINY) { |
| 326 |
< |
/* |
| 327 |
< |
* Compute specular reflection coefficient using |
| 328 |
< |
* gaussian distribution model. |
| 329 |
< |
*/ |
| 330 |
< |
/* roughness + source */ |
| 331 |
< |
dtmp = alpha2 + omega/(2.0*PI); |
| 332 |
< |
/* gaussian */ |
| 333 |
< |
dtmp = exp((DOT(vrefl,lr.rdir)-1.)/dtmp)/(2.*PI)/dtmp; |
| 334 |
< |
/* worth using? */ |
| 335 |
< |
if (dtmp > FTINY) { |
| 336 |
< |
copycolor(ctmp, lr.rcol); |
| 337 |
< |
dtmp *= omega; |
| 338 |
< |
scalecolor(ctmp, dtmp); |
| 339 |
< |
multcolor(ctmp, scolor); |
| 340 |
< |
addcolor(r->rcol, ctmp); |
| 341 |
< |
} |
| 342 |
< |
} |
| 343 |
< |
if (ldot < -FTINY && tdiff > FTINY) { |
| 344 |
< |
/* |
| 345 |
< |
* Compute diffuse transmission. |
| 346 |
< |
*/ |
| 200 |
< |
copycolor(ctmp, lr.rcol); |
| 201 |
< |
dtmp = -ldot * omega * tdiff / PI; |
| 202 |
< |
scalecolor(ctmp, dtmp); |
| 203 |
< |
multcolor(ctmp, mcolor); |
| 204 |
< |
addcolor(r->rcol, ctmp); |
| 205 |
< |
} |
| 206 |
< |
if (ldot < -FTINY && tspec > FTINY && alpha2 > FTINY) { |
| 207 |
< |
/* |
| 208 |
< |
* Compute specular transmission. |
| 209 |
< |
*/ |
| 210 |
< |
/* roughness + source */ |
| 211 |
< |
dtmp = alpha2 + omega/(2.0*PI); |
| 212 |
< |
/* gaussian */ |
| 213 |
< |
dtmp = exp((DOT(r->rdir,lr.rdir)-1.)/dtmp)/(2.*PI)/dtmp; |
| 214 |
< |
/* worth using? */ |
| 215 |
< |
if (dtmp > FTINY) { |
| 216 |
< |
copycolor(ctmp, lr.rcol); |
| 217 |
< |
dtmp *= tspec * omega; |
| 218 |
< |
scalecolor(ctmp, dtmp); |
| 219 |
< |
addcolor(r->rcol, ctmp); |
| 220 |
< |
} |
| 221 |
< |
} |
| 303 |
> |
static |
| 304 |
> |
gaussamp(r, np) /* sample gaussian specular */ |
| 305 |
> |
RAY *r; |
| 306 |
> |
register NORMDAT *np; |
| 307 |
> |
{ |
| 308 |
> |
RAY sr; |
| 309 |
> |
FVECT u, v, h; |
| 310 |
> |
double rv[2]; |
| 311 |
> |
double d, sinp, cosp; |
| 312 |
> |
register int i; |
| 313 |
> |
/* set up sample coordinates */ |
| 314 |
> |
v[0] = v[1] = v[2] = 0.0; |
| 315 |
> |
for (i = 0; i < 3; i++) |
| 316 |
> |
if (np->pnorm[i] < 0.6 && np->pnorm[i] > -0.6) |
| 317 |
> |
break; |
| 318 |
> |
v[i] = 1.0; |
| 319 |
> |
fcross(u, v, np->pnorm); |
| 320 |
> |
normalize(u); |
| 321 |
> |
fcross(v, np->pnorm, u); |
| 322 |
> |
/* compute reflection */ |
| 323 |
> |
if ((np->specfl & (SP_REFL|SP_RBLT)) == SP_REFL && |
| 324 |
> |
rayorigin(&sr, r, SPECULAR, np->rspec) == 0) { |
| 325 |
> |
dimlist[ndims++] = (int)np->mp; |
| 326 |
> |
d = urand(ilhash(dimlist,ndims)+samplendx); |
| 327 |
> |
multisamp(rv, 2, d); |
| 328 |
> |
d = 2.0*PI * rv[0]; |
| 329 |
> |
cosp = cos(d); |
| 330 |
> |
sinp = sin(d); |
| 331 |
> |
rv[1] = 1.0 - specjitter*rv[1]; |
| 332 |
> |
if (rv[1] <= FTINY) |
| 333 |
> |
d = 1.0; |
| 334 |
> |
else |
| 335 |
> |
d = sqrt( np->alpha2 * -log(rv[1]) ); |
| 336 |
> |
for (i = 0; i < 3; i++) |
| 337 |
> |
h[i] = np->pnorm[i] + d*(cosp*u[i] + sinp*v[i]); |
| 338 |
> |
d = -2.0 * DOT(h, r->rdir) / (1.0 + d*d); |
| 339 |
> |
for (i = 0; i < 3; i++) |
| 340 |
> |
sr.rdir[i] = r->rdir[i] + d*h[i]; |
| 341 |
> |
if (DOT(sr.rdir, r->ron) <= FTINY) |
| 342 |
> |
VCOPY(sr.rdir, np->vrefl); /* jitter no good */ |
| 343 |
> |
rayvalue(&sr); |
| 344 |
> |
multcolor(sr.rcol, np->scolor); |
| 345 |
> |
addcolor(r->rcol, sr.rcol); |
| 346 |
> |
ndims--; |
| 347 |
|
} |
| 348 |
+ |
/* compute transmission */ |
| 349 |
|
} |
