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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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static const char RCSid[] = "$Id$"; |
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#endif |
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|
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/* |
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* normal.c - shading function for normal materials. |
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* |
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* Later changes described in delta comments. |
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*/ |
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|
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#include "ray.h" |
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#include "copyright.h" |
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|
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#include "ray.h" |
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#include "ambient.h" |
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#include "source.h" |
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#include "otypes.h" |
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#include "rtotypes.h" |
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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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#ifndef MAXITER |
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#define MAXITER 10 /* maximum # specular ray attempts */ |
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#endif |
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/* estimate of Fresnel function */ |
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#define FRESNE(ci) (exp(-5.85*(ci)) - 0.00287989916) |
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#define FRESTHRESH 0.017999 /* minimum specularity for approx. */ |
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|
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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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* The computation of specular components has been simplified by |
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* numerous approximations and ommisions to improve speed. |
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* This routine implements the isotropic Gaussian |
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* model described by Ward in Siggraph `92 article. |
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* We orient the surface towards the incoming ray, so a single |
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* surface can be used to represent an infinitely thin object. |
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* |
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* red grn blu rspec rough trans tspec |
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*/ |
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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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#define SP_PURE 04 /* purely specular (zero roughness) */ |
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#define SP_FLAT 010 /* flat reflecting surface */ |
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#define SP_RBLT 020 /* reflection below sample threshold */ |
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#define SP_TBLT 040 /* transmission below threshold */ |
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|
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typedef struct { |
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OBJREC *mp; /* material pointer */ |
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RAY *rp; /* ray 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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double pdot; /* perturbed dot product */ |
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} NORMDAT; /* normal material data */ |
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|
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static srcdirf_t dirnorm; |
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static void gaussamp(RAY *r, NORMDAT *np); |
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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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static void |
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dirnorm( /* compute source contribution */ |
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COLOR cval, /* returned coefficient */ |
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void *nnp, /* 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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{ |
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register NORMDAT *np = nnp; |
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double ldot; |
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double dtmp; |
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int i; |
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double lrdiff, ltdiff; |
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double dtmp, d2, d3, d4; |
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FVECT vtmp; |
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COLOR ctmp; |
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|
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setcolor(cval, 0.0, 0.0, 0.0); |
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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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if (ldot > FTINY && np->rdiff > FTINY) { |
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/* Fresnel estimate */ |
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lrdiff = np->rdiff; |
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ltdiff = np->tdiff; |
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if (np->specfl & SP_PURE && np->rspec >= FRESTHRESH && |
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(lrdiff > FTINY) | (ltdiff > FTINY)) { |
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dtmp = 1. - FRESNE(fabs(ldot)); |
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lrdiff *= dtmp; |
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ltdiff *= dtmp; |
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} |
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|
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if (ldot > FTINY && lrdiff > 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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dtmp = ldot * omega * lrdiff * (1.0/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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* 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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dtmp = 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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dtmp += omega * (0.25/PI); |
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/* half vector */ |
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vtmp[0] = ldir[0] - np->rp->rdir[0]; |
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vtmp[1] = ldir[1] - np->rp->rdir[1]; |
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vtmp[2] = ldir[2] - np->rp->rdir[2]; |
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d2 = DOT(vtmp, np->pnorm); |
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d2 *= d2; |
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d3 = DOT(vtmp,vtmp); |
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d4 = (d3 - d2) / d2; |
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/* new W-G-M-D model */ |
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dtmp = exp(-d4/dtmp) * d3 / (PI * d2*d2 * 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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dtmp *= ldot * omega; |
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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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if (ldot < -FTINY && ltdiff > 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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dtmp = -ldot * omega * ltdiff * (1.0/PI); |
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scalecolor(ctmp, dtmp); |
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addcolor(cval, ctmp); |
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} |
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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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dtmp = np->alpha2 + omega*(1.0/PI); |
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/* Gaussian */ |
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dtmp = exp((2.*DOT(np->prdir,ldir)-2.)/dtmp)/(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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dtmp *= np->tspec * omega * sqrt(-ldot/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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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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extern int |
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m_normal( /* 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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{ |
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NORMDAT nd; |
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double fest; |
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double transtest, transdist; |
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double dtmp; |
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double mirtest, mirdist; |
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int hastexture; |
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double d; |
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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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return(1); |
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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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/* check for back side */ |
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if (r->rod < 0.0) { |
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if (!backvis && m->otype != MAT_TRANS) { |
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raytrans(r); |
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return(1); |
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} |
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raytexture(r, m->omod); |
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flipsurface(r); /* reorient if backvis */ |
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} else |
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raytexture(r, m->omod); |
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nd.mp = m; |
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nd.rp = r; |
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/* get material color */ |
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setcolor(nd.mcolor, m->oargs.farg[0], |
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m->oargs.farg[1], |
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nd.alpha2 = m->oargs.farg[4]; |
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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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nd.pdot = raynormal(nd.pnorm, r); /* perturb normal */ |
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|
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if ( (hastexture = (DOT(r->pert,r->pert) > FTINY*FTINY)) ) { |
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nd.pdot = raynormal(nd.pnorm, r); /* perturb normal */ |
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} else { |
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VCOPY(nd.pnorm, r->ron); |
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nd.pdot = r->rod; |
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} |
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if (r->ro != NULL && isflat(r->ro->otype)) |
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nd.specfl |= SP_FLAT; |
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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; |
226 |
< |
/* get specular component */ |
227 |
< |
if ((nd.rspec = m->oargs.farg[3]) > FTINY) { |
228 |
< |
nd.specfl |= SP_REFL; |
229 |
< |
/* compute specular color */ |
230 |
< |
if (m->otype == MAT_METAL) |
231 |
< |
copycolor(nd.scolor, nd.mcolor); |
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< |
else |
233 |
< |
setcolor(nd.scolor, 1.0, 1.0, 1.0); |
188 |
< |
scalecolor(nd.scolor, nd.rspec); |
189 |
< |
/* improved model */ |
190 |
< |
dtmp = exp(-BSPEC(m)*nd.pdot); |
191 |
< |
for (i = 0; i < 3; i++) |
192 |
< |
colval(nd.scolor,i) += (1.0-colval(nd.scolor,i))*dtmp; |
193 |
< |
nd.rspec += (1.0-nd.rspec)*dtmp; |
194 |
< |
/* check threshold */ |
195 |
< |
if (specthresh > FTINY && |
196 |
< |
((specthresh >= 1.-FTINY || |
197 |
< |
specthresh + (.1 - .2*urand(8199+samplendx)) |
198 |
< |
> nd.rspec))) |
199 |
< |
nd.specfl |= SP_RBLT; |
200 |
< |
/* compute reflected ray */ |
201 |
< |
for (i = 0; i < 3; i++) |
202 |
< |
nd.vrefl[i] = r->rdir[i] + 2.0*nd.pdot*nd.pnorm[i]; |
203 |
< |
|
204 |
< |
if (!(r->crtype & SHADOW) && nd.specfl & SP_PURE) { |
205 |
< |
RAY lr; |
206 |
< |
if (rayorigin(&lr, r, REFLECTED, nd.rspec) == 0) { |
207 |
< |
VCOPY(lr.rdir, nd.vrefl); |
208 |
< |
rayvalue(&lr); |
209 |
< |
multcolor(lr.rcol, nd.scolor); |
210 |
< |
addcolor(r->rcol, lr.rcol); |
211 |
< |
} |
212 |
< |
} |
213 |
< |
} |
225 |
> |
mirtest = transtest = 0; |
226 |
> |
mirdist = transdist = r->rot; |
227 |
> |
nd.rspec = m->oargs.farg[3]; |
228 |
> |
/* compute Fresnel approx. */ |
229 |
> |
if (nd.specfl & SP_PURE && nd.rspec >= FRESTHRESH) { |
230 |
> |
fest = FRESNE(r->rod); |
231 |
> |
nd.rspec += fest*(1. - nd.rspec); |
232 |
> |
} else |
233 |
> |
fest = 0.; |
234 |
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/* compute transmission */ |
235 |
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if (m->otype == MAT_TRANS) { |
236 |
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nd.trans = m->oargs.farg[5]*(1.0 - nd.rspec); |
239 |
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if (nd.tspec > FTINY) { |
240 |
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nd.specfl |= SP_TRAN; |
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/* check threshold */ |
242 |
< |
if (specthresh > FTINY && |
243 |
< |
((specthresh >= 1.-FTINY || |
224 |
< |
specthresh + |
225 |
< |
(.1 - .2*urand(7241+samplendx)) |
226 |
< |
> nd.tspec))) |
242 |
> |
if (!(nd.specfl & SP_PURE) && |
243 |
> |
specthresh >= nd.tspec-FTINY) |
244 |
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nd.specfl |= SP_TBLT; |
245 |
< |
if (r->crtype & SHADOW || |
229 |
< |
DOT(r->pert,r->pert) <= FTINY*FTINY) { |
245 |
> |
if (!hastexture || r->crtype & SHADOW) { |
246 |
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VCOPY(nd.prdir, r->rdir); |
247 |
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transtest = 2; |
248 |
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} else { |
249 |
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for (i = 0; i < 3; i++) /* perturb */ |
250 |
< |
nd.prdir[i] = r->rdir[i] - |
251 |
< |
.75*r->pert[i]; |
252 |
< |
normalize(nd.prdir); |
250 |
> |
nd.prdir[i] = r->rdir[i] - r->pert[i]; |
251 |
> |
if (DOT(nd.prdir, r->ron) < -FTINY) |
252 |
> |
normalize(nd.prdir); /* OK */ |
253 |
> |
else |
254 |
> |
VCOPY(nd.prdir, r->rdir); |
255 |
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} |
256 |
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} |
257 |
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} else |
258 |
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nd.tdiff = nd.tspec = nd.trans = 0.0; |
259 |
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/* transmitted ray */ |
260 |
< |
if ((nd.specfl&(SP_TRAN|SP_PURE)) == (SP_TRAN|SP_PURE)) { |
260 |
> |
if ((nd.specfl&(SP_TRAN|SP_PURE|SP_TBLT)) == (SP_TRAN|SP_PURE)) { |
261 |
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RAY lr; |
262 |
< |
if (rayorigin(&lr, r, TRANS, nd.tspec) == 0) { |
262 |
> |
copycolor(lr.rcoef, nd.mcolor); /* modified by color */ |
263 |
> |
scalecolor(lr.rcoef, nd.tspec); |
264 |
> |
if (rayorigin(&lr, TRANS, r, lr.rcoef) == 0) { |
265 |
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VCOPY(lr.rdir, nd.prdir); |
266 |
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rayvalue(&lr); |
267 |
< |
scalecolor(lr.rcol, nd.tspec); |
248 |
< |
multcolor(lr.rcol, nd.mcolor); /* modified by color */ |
267 |
> |
multcolor(lr.rcol, lr.rcoef); |
268 |
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addcolor(r->rcol, lr.rcol); |
269 |
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transtest *= bright(lr.rcol); |
270 |
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transdist = r->rot + lr.rt; |
271 |
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} |
272 |
< |
} |
272 |
> |
} else |
273 |
> |
transtest = 0; |
274 |
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|
275 |
< |
if (r->crtype & SHADOW) /* the rest is shadow */ |
276 |
< |
return; |
275 |
> |
if (r->crtype & SHADOW) { /* the rest is shadow */ |
276 |
> |
r->rt = transdist; |
277 |
> |
return(1); |
278 |
> |
} |
279 |
> |
/* get specular reflection */ |
280 |
> |
if (nd.rspec > FTINY) { |
281 |
> |
nd.specfl |= SP_REFL; |
282 |
> |
/* compute specular color */ |
283 |
> |
if (m->otype != MAT_METAL) { |
284 |
> |
setcolor(nd.scolor, nd.rspec, nd.rspec, nd.rspec); |
285 |
> |
} else if (fest > FTINY) { |
286 |
> |
d = nd.rspec*(1. - fest); |
287 |
> |
for (i = 0; i < 3; i++) |
288 |
> |
nd.scolor[i] = fest + nd.mcolor[i]*d; |
289 |
> |
} else { |
290 |
> |
copycolor(nd.scolor, nd.mcolor); |
291 |
> |
scalecolor(nd.scolor, nd.rspec); |
292 |
> |
} |
293 |
> |
/* check threshold */ |
294 |
> |
if (!(nd.specfl & SP_PURE) && specthresh >= nd.rspec-FTINY) |
295 |
> |
nd.specfl |= SP_RBLT; |
296 |
> |
/* compute reflected ray */ |
297 |
> |
VSUM(nd.vrefl, r->rdir, nd.pnorm, 2.*nd.pdot); |
298 |
> |
/* penetration? */ |
299 |
> |
if (hastexture && DOT(nd.vrefl, r->ron) <= FTINY) |
300 |
> |
VSUM(nd.vrefl, r->rdir, r->ron, 2.*r->rod); |
301 |
> |
checknorm(nd.vrefl); |
302 |
> |
} |
303 |
> |
/* reflected ray */ |
304 |
> |
if ((nd.specfl&(SP_REFL|SP_PURE|SP_RBLT)) == (SP_REFL|SP_PURE)) { |
305 |
> |
RAY lr; |
306 |
> |
if (rayorigin(&lr, REFLECTED, r, nd.scolor) == 0) { |
307 |
> |
VCOPY(lr.rdir, nd.vrefl); |
308 |
> |
rayvalue(&lr); |
309 |
> |
multcolor(lr.rcol, lr.rcoef); |
310 |
> |
addcolor(r->rcol, lr.rcol); |
311 |
> |
if (!hastexture && nd.specfl & SP_FLAT) { |
312 |
> |
mirtest = 2.*bright(lr.rcol); |
313 |
> |
mirdist = r->rot + lr.rt; |
314 |
> |
} |
315 |
> |
} |
316 |
> |
} |
317 |
|
/* diffuse reflection */ |
318 |
|
nd.rdiff = 1.0 - nd.trans - nd.rspec; |
319 |
|
|
320 |
|
if (nd.specfl & SP_PURE && nd.rdiff <= FTINY && nd.tdiff <= FTINY) |
321 |
< |
return; /* 100% pure specular */ |
321 |
> |
return(1); /* 100% pure specular */ |
322 |
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|
323 |
< |
if (r->ro->otype == OBJ_FACE || r->ro->otype == OBJ_RING) |
324 |
< |
nd.specfl |= SP_FLAT; |
323 |
> |
if (!(nd.specfl & SP_PURE)) |
324 |
> |
gaussamp(r, &nd); /* checks *BLT flags */ |
325 |
|
|
266 |
– |
if (nd.specfl & (SP_REFL|SP_TRAN) && !(nd.specfl & SP_PURE)) |
267 |
– |
gaussamp(r, &nd); |
268 |
– |
|
326 |
|
if (nd.rdiff > FTINY) { /* ambient from this side */ |
327 |
< |
ambient(ctmp, r); |
327 |
> |
copycolor(ctmp, nd.mcolor); /* modified by material color */ |
328 |
|
if (nd.specfl & SP_RBLT) |
329 |
|
scalecolor(ctmp, 1.0-nd.trans); |
330 |
|
else |
331 |
|
scalecolor(ctmp, nd.rdiff); |
332 |
< |
multcolor(ctmp, nd.mcolor); /* modified by material color */ |
332 |
> |
multambient(ctmp, r, hastexture ? nd.pnorm : r->ron); |
333 |
|
addcolor(r->rcol, ctmp); /* add to returned color */ |
334 |
|
} |
335 |
|
if (nd.tdiff > FTINY) { /* ambient from other side */ |
336 |
< |
flipsurface(r); |
280 |
< |
ambient(ctmp, r); |
336 |
> |
copycolor(ctmp, nd.mcolor); /* modified by color */ |
337 |
|
if (nd.specfl & SP_TBLT) |
338 |
|
scalecolor(ctmp, nd.trans); |
339 |
|
else |
340 |
|
scalecolor(ctmp, nd.tdiff); |
341 |
< |
multcolor(ctmp, nd.mcolor); /* modified by color */ |
341 |
> |
flipsurface(r); |
342 |
> |
if (hastexture) { |
343 |
> |
FVECT bnorm; |
344 |
> |
bnorm[0] = -nd.pnorm[0]; |
345 |
> |
bnorm[1] = -nd.pnorm[1]; |
346 |
> |
bnorm[2] = -nd.pnorm[2]; |
347 |
> |
multambient(ctmp, r, bnorm); |
348 |
> |
} else |
349 |
> |
multambient(ctmp, r, r->ron); |
350 |
|
addcolor(r->rcol, ctmp); |
351 |
|
flipsurface(r); |
352 |
|
} |
353 |
|
/* add direct component */ |
354 |
|
direct(r, dirnorm, &nd); |
355 |
|
/* check distance */ |
356 |
< |
if (transtest > bright(r->rcol)) |
356 |
> |
d = bright(r->rcol); |
357 |
> |
if (transtest > d) |
358 |
|
r->rt = transdist; |
359 |
+ |
else if (mirtest > d) |
360 |
+ |
r->rt = mirdist; |
361 |
+ |
|
362 |
+ |
return(1); |
363 |
|
} |
364 |
|
|
365 |
|
|
366 |
< |
static |
367 |
< |
gaussamp(r, np) /* sample gaussian specular */ |
368 |
< |
RAY *r; |
369 |
< |
register NORMDAT *np; |
366 |
> |
static void |
367 |
> |
gaussamp( /* sample Gaussian specular */ |
368 |
> |
RAY *r, |
369 |
> |
register NORMDAT *np |
370 |
> |
) |
371 |
|
{ |
372 |
|
RAY sr; |
373 |
|
FVECT u, v, h; |
374 |
|
double rv[2]; |
375 |
|
double d, sinp, cosp; |
376 |
< |
int ntries; |
376 |
> |
COLOR scol; |
377 |
> |
int maxiter, ntrials, nstarget, nstaken; |
378 |
|
register int i; |
379 |
+ |
/* quick test */ |
380 |
+ |
if ((np->specfl & (SP_REFL|SP_RBLT)) != SP_REFL && |
381 |
+ |
(np->specfl & (SP_TRAN|SP_TBLT)) != SP_TRAN) |
382 |
+ |
return; |
383 |
|
/* set up sample coordinates */ |
384 |
|
v[0] = v[1] = v[2] = 0.0; |
385 |
|
for (i = 0; i < 3; i++) |
391 |
|
fcross(v, np->pnorm, u); |
392 |
|
/* compute reflection */ |
393 |
|
if ((np->specfl & (SP_REFL|SP_RBLT)) == SP_REFL && |
394 |
< |
rayorigin(&sr, r, SPECULAR, np->rspec) == 0) { |
395 |
< |
dimlist[ndims++] = (int)np->mp; |
396 |
< |
for (ntries = 0; ntries < 10; ntries++) { |
397 |
< |
dimlist[ndims] = ntries * 8912; |
398 |
< |
d = urand(ilhash(dimlist,ndims+1)+samplendx); |
394 |
> |
rayorigin(&sr, SPECULAR, r, np->scolor) == 0) { |
395 |
> |
nstarget = 1; |
396 |
> |
if (specjitter > 1.5) { /* multiple samples? */ |
397 |
> |
nstarget = specjitter*r->rweight + .5; |
398 |
> |
if (sr.rweight <= minweight*nstarget) |
399 |
> |
nstarget = sr.rweight/minweight; |
400 |
> |
if (nstarget > 1) { |
401 |
> |
d = 1./nstarget; |
402 |
> |
scalecolor(sr.rcoef, d); |
403 |
> |
sr.rweight *= d; |
404 |
> |
} else |
405 |
> |
nstarget = 1; |
406 |
> |
} |
407 |
> |
setcolor(scol, 0., 0., 0.); |
408 |
> |
dimlist[ndims++] = (int)(size_t)np->mp; |
409 |
> |
maxiter = MAXITER*nstarget; |
410 |
> |
for (nstaken = ntrials = 0; nstaken < nstarget && |
411 |
> |
ntrials < maxiter; ntrials++) { |
412 |
> |
if (ntrials) |
413 |
> |
d = frandom(); |
414 |
> |
else |
415 |
> |
d = urand(ilhash(dimlist,ndims)+samplendx); |
416 |
|
multisamp(rv, 2, d); |
417 |
|
d = 2.0*PI * rv[0]; |
418 |
< |
cosp = cos(d); |
419 |
< |
sinp = sin(d); |
420 |
< |
rv[1] = 1.0 - specjitter*rv[1]; |
418 |
> |
cosp = tcos(d); |
419 |
> |
sinp = tsin(d); |
420 |
> |
if ((0. <= specjitter) & (specjitter < 1.)) |
421 |
> |
rv[1] = 1.0 - specjitter*rv[1]; |
422 |
|
if (rv[1] <= FTINY) |
423 |
|
d = 1.0; |
424 |
|
else |
426 |
|
for (i = 0; i < 3; i++) |
427 |
|
h[i] = np->pnorm[i] + d*(cosp*u[i] + sinp*v[i]); |
428 |
|
d = -2.0 * DOT(h, r->rdir) / (1.0 + d*d); |
429 |
< |
for (i = 0; i < 3; i++) |
430 |
< |
sr.rdir[i] = r->rdir[i] + d*h[i]; |
431 |
< |
if (DOT(sr.rdir, r->ron) > FTINY) { |
429 |
> |
VSUM(sr.rdir, r->rdir, h, d); |
430 |
> |
/* sample rejection test */ |
431 |
> |
if ((d = DOT(sr.rdir, r->ron)) <= FTINY) |
432 |
> |
continue; |
433 |
> |
checknorm(sr.rdir); |
434 |
> |
if (nstarget > 1) { /* W-G-M-D adjustment */ |
435 |
> |
if (nstaken) rayclear(&sr); |
436 |
|
rayvalue(&sr); |
437 |
< |
multcolor(sr.rcol, np->scolor); |
437 |
> |
d = 2./(1. + r->rod/d); |
438 |
> |
scalecolor(sr.rcol, d); |
439 |
> |
addcolor(scol, sr.rcol); |
440 |
> |
} else { |
441 |
> |
rayvalue(&sr); |
442 |
> |
multcolor(sr.rcol, sr.rcoef); |
443 |
|
addcolor(r->rcol, sr.rcol); |
342 |
– |
break; |
444 |
|
} |
445 |
+ |
++nstaken; |
446 |
|
} |
447 |
+ |
if (nstarget > 1) { /* final W-G-M-D weighting */ |
448 |
+ |
multcolor(scol, sr.rcoef); |
449 |
+ |
d = (double)nstarget/ntrials; |
450 |
+ |
scalecolor(scol, d); |
451 |
+ |
addcolor(r->rcol, scol); |
452 |
+ |
} |
453 |
|
ndims--; |
454 |
|
} |
455 |
|
/* compute transmission */ |
456 |
+ |
copycolor(sr.rcoef, np->mcolor); /* modified by color */ |
457 |
+ |
scalecolor(sr.rcoef, np->tspec); |
458 |
+ |
if ((np->specfl & (SP_TRAN|SP_TBLT)) == SP_TRAN && |
459 |
+ |
rayorigin(&sr, SPECULAR, r, sr.rcoef) == 0) { |
460 |
+ |
nstarget = 1; |
461 |
+ |
if (specjitter > 1.5) { /* multiple samples? */ |
462 |
+ |
nstarget = specjitter*r->rweight + .5; |
463 |
+ |
if (sr.rweight <= minweight*nstarget) |
464 |
+ |
nstarget = sr.rweight/minweight; |
465 |
+ |
if (nstarget > 1) { |
466 |
+ |
d = 1./nstarget; |
467 |
+ |
scalecolor(sr.rcoef, d); |
468 |
+ |
sr.rweight *= d; |
469 |
+ |
} else |
470 |
+ |
nstarget = 1; |
471 |
+ |
} |
472 |
+ |
dimlist[ndims++] = (int)(size_t)np->mp; |
473 |
+ |
maxiter = MAXITER*nstarget; |
474 |
+ |
for (nstaken = ntrials = 0; nstaken < nstarget && |
475 |
+ |
ntrials < maxiter; ntrials++) { |
476 |
+ |
if (ntrials) |
477 |
+ |
d = frandom(); |
478 |
+ |
else |
479 |
+ |
d = urand(ilhash(dimlist,ndims)+samplendx); |
480 |
+ |
multisamp(rv, 2, d); |
481 |
+ |
d = 2.0*PI * rv[0]; |
482 |
+ |
cosp = tcos(d); |
483 |
+ |
sinp = tsin(d); |
484 |
+ |
if ((0. <= specjitter) & (specjitter < 1.)) |
485 |
+ |
rv[1] = 1.0 - specjitter*rv[1]; |
486 |
+ |
if (rv[1] <= FTINY) |
487 |
+ |
d = 1.0; |
488 |
+ |
else |
489 |
+ |
d = sqrt( np->alpha2 * -log(rv[1]) ); |
490 |
+ |
for (i = 0; i < 3; i++) |
491 |
+ |
sr.rdir[i] = np->prdir[i] + d*(cosp*u[i] + sinp*v[i]); |
492 |
+ |
/* sample rejection test */ |
493 |
+ |
if (DOT(sr.rdir, r->ron) >= -FTINY) |
494 |
+ |
continue; |
495 |
+ |
normalize(sr.rdir); /* OK, normalize */ |
496 |
+ |
if (nstaken) /* multi-sampling */ |
497 |
+ |
rayclear(&sr); |
498 |
+ |
rayvalue(&sr); |
499 |
+ |
multcolor(sr.rcol, sr.rcoef); |
500 |
+ |
addcolor(r->rcol, sr.rcol); |
501 |
+ |
++nstaken; |
502 |
+ |
} |
503 |
+ |
ndims--; |
504 |
+ |
} |
505 |
|
} |