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#include "random.h" |
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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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* This anisotropic reflection model uses a variant on the |
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* exponential Gaussian used in normal.c. |
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* 8 red grn blu rspec u-rough v-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_BADU 020 /* bad u direction calculation */ |
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> |
#define SP_FLAT 04 /* reflecting surface is flat */ |
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> |
#define SP_RBLT 010 /* reflection below sample threshold */ |
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#define SP_TBLT 020 /* transmission below threshold */ |
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> |
#define SP_BADU 040 /* bad u direction calculation */ |
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typedef struct { |
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RAY *rp; /* ray pointer */ |
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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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FVECT vrefl; /* vector in reflected direction */ |
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FVECT prdir; /* vector in transmitted direction */ |
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FVECT u, v; /* u and v vectors orienting anisotropy */ |
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double u_alpha; /* u roughness */ |
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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_BADU)) == SP_REFL) { |
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> |
if (ldot > FTINY && (np->specfl&(SP_REFL|SP_BADU)) == SP_REFL) { |
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/* |
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* Compute specular reflection coefficient using |
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* anisotropic gaussian distribution model. |
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*/ |
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/* roughness + source */ |
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au2 = av2 = omega/(4.0*PI); |
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/* add source width if flat */ |
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if (np->specfl & SP_FLAT) |
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au2 = av2 = omega/(4.0*PI); |
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else |
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au2 = av2 = 0.0; |
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au2 += np->u_alpha * np->u_alpha; |
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av2 += np->v_alpha * np->v_alpha; |
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/* half vector */ |
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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_BADU)) == SP_TRAN) { |
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> |
if (ldot < -FTINY && (np->specfl&(SP_TRAN|SP_BADU)) == 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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register RAY *r; |
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{ |
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ANISODAT 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_TRANS2) |
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> |
if (r->crtype & SHADOW) |
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return; |
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|
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if (m->oargs.nfargs != (m->otype == MAT_TRANS2 ? 8 : 6)) |
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objerror(m, USER, "bad number of real arguments"); |
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nd.rp = r; |
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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.specfl = 0; |
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nd.u_alpha = m->oargs.farg[4]; |
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nd.v_alpha = m->oargs.farg[5]; |
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if (nd.u_alpha <= FTINY || nd.v_alpha <= FTINY) |
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nd.specfl |= SP_PURE; |
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> |
if (nd.u_alpha < 1e-6 || nd.v_alpha <= 1e-6) |
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objerror(m, USER, "roughness too small"); |
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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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if (nd.pdot < .001) |
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nd.pdot = .001; /* non-zero for diraniso() */ |
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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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if ((nd.rspec = m->oargs.farg[3]) > FTINY) { |
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nd.specfl |= SP_REFL; |
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else |
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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)*nd.pdot); |
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> |
/* check threshold */ |
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> |
if (specthresh > FTINY && |
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> |
(specthresh >= 1.-FTINY || |
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specthresh > nd.rspec)) |
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> |
nd.specfl |= SP_RBLT; |
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> |
/* compute refl. direction */ |
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for (i = 0; i < 3; i++) |
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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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|
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if (!(r->crtype & SHADOW) && nd.specfl & SP_PURE) { |
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< |
RAY lr; |
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< |
if (rayorigin(&lr, r, REFLECTED, nd.rspec) == 0) { |
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< |
for (i = 0; i < 3; i++) |
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lr.rdir[i] = r->rdir[i] + |
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2.0*nd.pdot*nd.pnorm[i]; |
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rayvalue(&lr); |
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multcolor(lr.rcol, nd.scolor); |
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addcolor(r->rcol, lr.rcol); |
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< |
} |
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< |
} |
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> |
nd.vrefl[i] = r->rdir[i] + 2.0*nd.pdot*nd.pnorm[i]; |
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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]; |
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} |
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/* compute transmission */ |
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if (m->otype == MAT_TRANS) { |
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nd.tdiff = nd.trans - nd.tspec; |
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if (nd.tspec > FTINY) { |
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nd.specfl |= SP_TRAN; |
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if (r->crtype & SHADOW || |
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DOT(r->pert,r->pert) <= FTINY*FTINY) { |
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> |
/* check threshold */ |
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if (specthresh > FTINY && |
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(specthresh >= 1.-FTINY || |
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specthresh > nd.tspec)) |
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> |
nd.specfl |= SP_TBLT; |
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> |
if (DOT(r->pert,r->pert) <= FTINY*FTINY) { |
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VCOPY(nd.prdir, r->rdir); |
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transtest = 2; |
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} else { |
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for (i = 0; i < 3; i++) /* perturb */ |
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nd.prdir[i] = r->rdir[i] - |
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< |
.75*r->pert[i]; |
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< |
normalize(nd.prdir); |
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> |
0.5*r->pert[i]; |
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> |
if (DOT(nd.prdir, r->ron) < -FTINY) |
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> |
normalize(nd.prdir); /* OK */ |
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> |
else |
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> |
VCOPY(nd.prdir, r->rdir); |
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} |
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} |
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} else |
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nd.tdiff = nd.tspec = nd.trans = 0.0; |
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/* transmitted ray */ |
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if ((nd.specfl&(SP_TRAN|SP_PURE)) == (SP_TRAN|SP_PURE)) { |
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RAY lr; |
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if (rayorigin(&lr, r, TRANS, nd.tspec) == 0) { |
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– |
VCOPY(lr.rdir, nd.prdir); |
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– |
rayvalue(&lr); |
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scalecolor(lr.rcol, nd.tspec); |
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multcolor(lr.rcol, nd.mcolor); /* modified by color */ |
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addcolor(r->rcol, lr.rcol); |
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transtest *= bright(lr.rcol); |
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transdist = r->rot + lr.rt; |
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– |
} |
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– |
} |
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if (r->crtype & SHADOW) /* the rest is shadow */ |
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– |
return; |
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/* diffuse reflection */ |
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nd.rdiff = 1.0 - nd.trans - nd.rspec; |
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< |
if (nd.specfl & SP_PURE && nd.rdiff <= FTINY && nd.tdiff <= FTINY) |
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< |
return; /* 100% pure specular */ |
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> |
if (r->ro != NULL && (r->ro->otype == OBJ_FACE || |
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> |
r->ro->otype == OBJ_RING)) |
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> |
nd.specfl |= SP_FLAT; |
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getacoords(r, &nd); /* set up coordinates */ |
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< |
if (nd.specfl & (SP_REFL|SP_TRAN) && !(nd.specfl & (SP_PURE|SP_BADU))) |
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> |
if (nd.specfl & (SP_REFL|SP_TRAN) && !(nd.specfl & SP_BADU)) |
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agaussamp(r, &nd); |
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if (nd.rdiff > FTINY) { /* ambient from this side */ |
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ambient(ctmp, r); |
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< |
scalecolor(ctmp, nd.rdiff); |
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> |
if (nd.specfl & SP_RBLT) |
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> |
scalecolor(ctmp, 1.0-nd.trans); |
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> |
else |
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> |
scalecolor(ctmp, nd.rdiff); |
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multcolor(ctmp, nd.mcolor); /* modified by material color */ |
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addcolor(r->rcol, ctmp); /* add to returned color */ |
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} |
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if (nd.tdiff > FTINY) { /* ambient from other side */ |
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flipsurface(r); |
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ambient(ctmp, r); |
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< |
scalecolor(ctmp, nd.tdiff); |
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> |
if (nd.specfl & SP_TBLT) |
| 263 |
> |
scalecolor(ctmp, nd.trans); |
| 264 |
> |
else |
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> |
scalecolor(ctmp, nd.tdiff); |
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multcolor(ctmp, nd.mcolor); /* modified by color */ |
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addcolor(r->rcol, ctmp); |
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flipsurface(r); |
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} |
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/* add direct component */ |
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direct(r, diraniso, &nd); |
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/* check distance */ |
| 276 |
– |
if (transtest > bright(r->rcol)) |
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r->rt = transdist; |
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} |
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| 274 |
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|
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FVECT h; |
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double rv[2]; |
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double d, sinp, cosp; |
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– |
int confuse; |
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|
register int i; |
| 314 |
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/* compute reflection */ |
| 315 |
< |
if (np->specfl & SP_REFL && |
| 315 |
> |
if ((np->specfl & (SP_REFL|SP_RBLT)) == SP_REFL && |
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rayorigin(&sr, r, SPECULAR, np->rspec) == 0) { |
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– |
confuse = 0; |
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dimlist[ndims++] = (int)np->mp; |
| 318 |
< |
refagain: |
| 327 |
< |
dimlist[ndims] = confuse += 3601; |
| 328 |
< |
d = urand(ilhash(dimlist,ndims+1)+samplendx); |
| 318 |
> |
d = urand(ilhash(dimlist,ndims)+samplendx); |
| 319 |
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multisamp(rv, 2, d); |
| 320 |
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d = 2.0*PI * rv[0]; |
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cosp = np->u_alpha * cos(d); |
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d = sqrt(cosp*cosp + sinp*sinp); |
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cosp /= d; |
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sinp /= d; |
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+ |
rv[1] = 1.0 - specjitter*rv[1]; |
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if (rv[1] <= FTINY) |
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d = 1.0; |
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else |
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< |
d = sqrt( -log(rv[1]) / |
| 330 |
> |
d = sqrt(-log(rv[1]) / |
| 331 |
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(cosp*cosp/(np->u_alpha*np->u_alpha) + |
| 332 |
< |
sinp*sinp/(np->v_alpha*np->v_alpha)) ); |
| 332 |
> |
sinp*sinp/(np->v_alpha*np->v_alpha))); |
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for (i = 0; i < 3; i++) |
| 334 |
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h[i] = np->pnorm[i] + |
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< |
d*(cosp*np->u[i] + sinp*np->v[i]); |
| 335 |
> |
d*(cosp*np->u[i] + sinp*np->v[i]); |
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d = -2.0 * DOT(h, r->rdir) / (1.0 + d*d); |
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for (i = 0; i < 3; i++) |
| 338 |
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sr.rdir[i] = r->rdir[i] + d*h[i]; |
| 339 |
< |
if (DOT(sr.rdir, r->ron) <= FTINY) /* oops! */ |
| 340 |
< |
goto refagain; |
| 339 |
> |
if (DOT(sr.rdir, r->ron) <= FTINY) /* penetration? */ |
| 340 |
> |
VCOPY(sr.rdir, np->vrefl); /* jitter no good */ |
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rayvalue(&sr); |
| 342 |
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multcolor(sr.rcol, np->scolor); |
| 343 |
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addcolor(r->rcol, sr.rcol); |
| 344 |
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ndims--; |
| 345 |
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} |
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/* compute transmission */ |
| 347 |
+ |
if ((np->specfl & (SP_TRAN|SP_TBLT)) == SP_TRAN && |
| 348 |
+ |
rayorigin(&sr, r, SPECULAR, np->tspec) == 0) { |
| 349 |
+ |
dimlist[ndims++] = (int)np->mp; |
| 350 |
+ |
d = urand(ilhash(dimlist,ndims)+1823+samplendx); |
| 351 |
+ |
multisamp(rv, 2, d); |
| 352 |
+ |
d = 2.0*PI * rv[0]; |
| 353 |
+ |
cosp = cos(d); |
| 354 |
+ |
sinp = sin(d); |
| 355 |
+ |
rv[1] = 1.0 - specjitter*rv[1]; |
| 356 |
+ |
if (rv[1] <= FTINY) |
| 357 |
+ |
d = 1.0; |
| 358 |
+ |
else |
| 359 |
+ |
d = sqrt(-log(rv[1]) / |
| 360 |
+ |
(cosp*cosp*4./(np->u_alpha*np->u_alpha) + |
| 361 |
+ |
sinp*sinp*4./(np->v_alpha*np->v_alpha))); |
| 362 |
+ |
for (i = 0; i < 3; i++) |
| 363 |
+ |
sr.rdir[i] = np->prdir[i] + |
| 364 |
+ |
d*(cosp*np->u[i] + sinp*np->v[i]); |
| 365 |
+ |
if (DOT(sr.rdir, r->ron) < -FTINY) |
| 366 |
+ |
normalize(sr.rdir); /* OK, normalize */ |
| 367 |
+ |
else |
| 368 |
+ |
VCOPY(sr.rdir, np->prdir); /* else no jitter */ |
| 369 |
+ |
rayvalue(&sr); |
| 370 |
+ |
scalecolor(sr.rcol, np->tspec); |
| 371 |
+ |
multcolor(sr.rcol, np->mcolor); /* modify by color */ |
| 372 |
+ |
addcolor(r->rcol, sr.rcol); |
| 373 |
+ |
ndims--; |
| 374 |
+ |
} |
| 375 |
|
} |
