--- ray/src/rt/aniso.c 1992/05/14 11:32:09 2.15 +++ ray/src/rt/aniso.c 2004/09/20 17:32:04 2.42 @@ -1,27 +1,27 @@ -/* Copyright (c) 1992 Regents of the University of California */ - #ifndef lint -static char SCCSid[] = "$SunId$ LBL"; +static const char RCSid[] = "$Id: aniso.c,v 2.42 2004/09/20 17:32:04 greg Exp $"; #endif - /* * Shading functions for anisotropic materials. */ -#include "ray.h" +#include "copyright.h" +#include "ray.h" +#include "ambient.h" #include "otypes.h" - +#include "rtotypes.h" +#include "source.h" #include "func.h" - #include "random.h" -extern double specthresh; /* specular sampling threshold */ -extern double specjitter; /* specular sampling jitter */ +#ifndef MAXITER +#define MAXITER 10 /* maximum # specular ray attempts */ +#endif /* - * This anisotropic reflection model uses a variant on the - * exponential Gaussian used in normal.c. + * This routine implements the anisotropic Gaussian + * model described by Ward in Siggraph `92 article. * We orient the surface towards the incoming ray, so a single * surface can be used to represent an infinitely thin object. * @@ -34,8 +34,6 @@ extern double specjitter; /* specular sampling jitte * 8 red grn blu rspec u-rough v-rough trans tspec */ -#define BSPEC(m) (6.0) /* specularity parameter b */ - /* specularity flags */ #define SP_REFL 01 /* has reflected specular component */ #define SP_TRAN 02 /* has transmitted specular */ @@ -62,15 +60,22 @@ typedef struct { double pdot; /* perturbed dot product */ } ANISODAT; /* anisotropic material data */ +static srcdirf_t diraniso; +static void getacoords(RAY *r, ANISODAT *np); +static void agaussamp(RAY *r, ANISODAT *np); -diraniso(cval, np, ldir, omega) /* compute source contribution */ -COLOR cval; /* returned coefficient */ -register ANISODAT *np; /* material data */ -FVECT ldir; /* light source direction */ -double omega; /* light source size */ + +static void +diraniso( /* compute source contribution */ + COLOR cval, /* returned coefficient */ + void *nnp, /* material data */ + FVECT ldir, /* light source direction */ + double omega /* light source size */ +) { + register ANISODAT *np = nnp; double ldot; - double dtmp, dtmp2; + double dtmp, dtmp1, dtmp2; FVECT h; double au2, av2; COLOR ctmp; @@ -89,7 +94,7 @@ double omega; /* light source size */ * modified by the color of the material. */ copycolor(ctmp, np->mcolor); - dtmp = ldot * omega * np->rdiff / PI; + dtmp = ldot * omega * np->rdiff * (1.0/PI); scalecolor(ctmp, dtmp); addcolor(cval, ctmp); } @@ -100,28 +105,28 @@ double omega; /* light source size */ */ /* add source width if flat */ if (np->specfl & SP_FLAT) - au2 = av2 = omega/(4.0*PI); + au2 = av2 = omega * (0.25/PI); else au2 = av2 = 0.0; - au2 += np->u_alpha * np->u_alpha; - av2 += np->v_alpha * np->v_alpha; + au2 += np->u_alpha*np->u_alpha; + av2 += np->v_alpha*np->v_alpha; /* half vector */ h[0] = ldir[0] - np->rp->rdir[0]; h[1] = ldir[1] - np->rp->rdir[1]; h[2] = ldir[2] - np->rp->rdir[2]; - normalize(h); /* ellipse */ - dtmp = DOT(np->u, h); - dtmp *= dtmp / au2; + dtmp1 = DOT(np->u, h); + dtmp1 *= dtmp1 / au2; dtmp2 = DOT(np->v, h); dtmp2 *= dtmp2 / av2; /* gaussian */ - dtmp = (dtmp + dtmp2) / (1.0 + DOT(np->pnorm, h)); - dtmp = exp(-2.0*dtmp) / (4.0*PI * sqrt(au2*av2)); + dtmp = DOT(np->pnorm, h); + dtmp = (dtmp1 + dtmp2) / (dtmp*dtmp); + dtmp = exp(-dtmp) / (4.0*PI * np->pdot * sqrt(au2*av2)); /* worth using? */ if (dtmp > FTINY) { copycolor(ctmp, np->scolor); - dtmp *= omega * sqrt(ldot/np->pdot); + dtmp *= omega; scalecolor(ctmp, dtmp); addcolor(cval, ctmp); } @@ -131,7 +136,7 @@ double omega; /* light source size */ * Compute diffuse transmission. */ copycolor(ctmp, np->mcolor); - dtmp = -ldot * omega * np->tdiff / PI; + dtmp = -ldot * omega * np->tdiff * (1.0/PI); scalecolor(ctmp, dtmp); addcolor(cval, ctmp); } @@ -141,12 +146,32 @@ double omega; /* light source size */ * is always modified by material color. */ /* roughness + source */ + au2 = av2 = omega * (1.0/PI); + au2 += np->u_alpha*np->u_alpha; + av2 += np->v_alpha*np->v_alpha; + /* "half vector" */ + h[0] = ldir[0] - np->prdir[0]; + h[1] = ldir[1] - np->prdir[1]; + h[2] = ldir[2] - np->prdir[2]; + dtmp = DOT(h,h); + if (dtmp > FTINY*FTINY) { + dtmp1 = DOT(h,np->pnorm); + dtmp = 1.0 - dtmp1*dtmp1/dtmp; + if (dtmp > FTINY*FTINY) { + dtmp1 = DOT(h,np->u); + dtmp1 *= dtmp1 / au2; + dtmp2 = DOT(h,np->v); + dtmp2 *= dtmp2 / av2; + dtmp = (dtmp1 + dtmp2) / dtmp; + } + } else + dtmp = 0.0; /* gaussian */ - dtmp = 0.0; + dtmp = exp(-dtmp) / (PI * np->pdot * sqrt(au2*av2)); /* worth using? */ if (dtmp > FTINY) { copycolor(ctmp, np->mcolor); - dtmp *= np->tspec * omega * sqrt(ldot/np->pdot); + dtmp *= np->tspec * omega; scalecolor(ctmp, dtmp); addcolor(cval, ctmp); } @@ -154,23 +179,34 @@ double omega; /* light source size */ } -m_aniso(m, r) /* shade ray that hit something anisotropic */ -register OBJREC *m; -register RAY *r; +extern int +m_aniso( /* shade ray that hit something anisotropic */ + register OBJREC *m, + register RAY *r +) { ANISODAT nd; - double dtmp; COLOR ctmp; register int i; /* easy shadow test */ if (r->crtype & SHADOW) - return; + return(1); if (m->oargs.nfargs != (m->otype == MAT_TRANS2 ? 8 : 6)) objerror(m, USER, "bad number of real arguments"); + /* check for back side */ + if (r->rod < 0.0) { + if (!backvis && m->otype != MAT_TRANS2) { + raytrans(r); + return(1); + } + raytexture(r, m->omod); + flipsurface(r); /* reorient if backvis */ + } else + raytexture(r, m->omod); + /* get material color */ nd.mp = m; nd.rp = r; - /* get material color */ setcolor(nd.mcolor, m->oargs.farg[0], m->oargs.farg[1], m->oargs.farg[2]); @@ -178,13 +214,9 @@ register RAY *r; nd.specfl = 0; nd.u_alpha = m->oargs.farg[4]; nd.v_alpha = m->oargs.farg[5]; - if (nd.u_alpha < 1e-6 || nd.v_alpha <= 1e-6) + if (nd.u_alpha < FTINY || nd.v_alpha <= FTINY) objerror(m, USER, "roughness too small"); - /* reorient if necessary */ - if (r->rod < 0.0) - flipsurface(r); - /* get modifiers */ - raytexture(r, m->omod); + nd.pdot = raynormal(nd.pnorm, r); /* perturb normal */ if (nd.pdot < .001) nd.pdot = .001; /* non-zero for diraniso() */ @@ -198,15 +230,8 @@ register RAY *r; else setcolor(nd.scolor, 1.0, 1.0, 1.0); scalecolor(nd.scolor, nd.rspec); - /* improved model */ - dtmp = exp(-BSPEC(m)*nd.pdot); - for (i = 0; i < 3; i++) - colval(nd.scolor,i) += (1.0-colval(nd.scolor,i))*dtmp; - nd.rspec += (1.0-nd.rspec)*dtmp; /* check threshold */ - if (specthresh > FTINY && - (specthresh >= 1.-FTINY || - specthresh + .05 - .1*frandom() > nd.rspec)) + if (specthresh >= nd.rspec-FTINY) nd.specfl |= SP_RBLT; /* compute refl. direction */ for (i = 0; i < 3; i++) @@ -216,23 +241,20 @@ register RAY *r; nd.vrefl[i] = r->rdir[i] + 2.*r->rod*r->ron[i]; } /* compute transmission */ - if (m->otype == MAT_TRANS) { + if (m->otype == MAT_TRANS2) { nd.trans = m->oargs.farg[6]*(1.0 - nd.rspec); nd.tspec = nd.trans * m->oargs.farg[7]; nd.tdiff = nd.trans - nd.tspec; if (nd.tspec > FTINY) { nd.specfl |= SP_TRAN; /* check threshold */ - if (specthresh > FTINY && - (specthresh >= 1.-FTINY || - specthresh + .05 - .1*frandom() > nd.tspec)) + if (specthresh >= nd.tspec-FTINY) nd.specfl |= SP_TBLT; if (DOT(r->pert,r->pert) <= FTINY*FTINY) { VCOPY(nd.prdir, r->rdir); } else { for (i = 0; i < 3; i++) /* perturb */ - nd.prdir[i] = r->rdir[i] - - 0.5*r->pert[i]; + nd.prdir[i] = r->rdir[i] - r->pert[i]; if (DOT(nd.prdir, r->ron) < -FTINY) normalize(nd.prdir); /* OK */ else @@ -245,8 +267,7 @@ register RAY *r; /* diffuse reflection */ nd.rdiff = 1.0 - nd.trans - nd.rspec; - if (r->ro != NULL && (r->ro->otype == OBJ_FACE || - r->ro->otype == OBJ_RING)) + if (r->ro != NULL && isflat(r->ro->otype)) nd.specfl |= SP_FLAT; getacoords(r, &nd); /* set up coordinates */ @@ -255,7 +276,7 @@ register RAY *r; agaussamp(r, &nd); if (nd.rdiff > FTINY) { /* ambient from this side */ - ambient(ctmp, r); + ambient(ctmp, r, nd.pnorm); if (nd.specfl & SP_RBLT) scalecolor(ctmp, 1.0-nd.trans); else @@ -264,8 +285,13 @@ register RAY *r; addcolor(r->rcol, ctmp); /* add to returned color */ } if (nd.tdiff > FTINY) { /* ambient from other side */ + FVECT bnorm; + flipsurface(r); - ambient(ctmp, r); + bnorm[0] = -nd.pnorm[0]; + bnorm[1] = -nd.pnorm[1]; + bnorm[2] = -nd.pnorm[2]; + ambient(ctmp, r, bnorm); if (nd.specfl & SP_TBLT) scalecolor(ctmp, nd.trans); else @@ -276,13 +302,16 @@ register RAY *r; } /* add direct component */ direct(r, diraniso, &nd); + + return(1); } -static -getacoords(r, np) /* set up coordinate system */ -RAY *r; -register ANISODAT *np; +static void +getacoords( /* set up coordinate system */ + RAY *r, + register ANISODAT *np +) { register MFUNC *mf; register int i; @@ -292,12 +321,13 @@ register ANISODAT *np; errno = 0; for (i = 0; i < 3; i++) np->u[i] = evalue(mf->ep[i]); - if (errno) { + if (errno == EDOM || errno == ERANGE) { objerror(np->mp, WARNING, "compute error"); np->specfl |= SP_BADU; return; } - multv3(np->u, np->u, mf->f->xfm); + if (mf->f != &unitxf) + multv3(np->u, np->u, mf->f->xfm); fcross(np->v, np->pnorm, np->u); if (normalize(np->v) == 0.0) { objerror(np->mp, WARNING, "illegal orientation vector"); @@ -308,75 +338,91 @@ register ANISODAT *np; } -static -agaussamp(r, np) /* sample anisotropic gaussian specular */ -RAY *r; -register ANISODAT *np; +static void +agaussamp( /* sample anisotropic gaussian specular */ + RAY *r, + register ANISODAT *np +) { RAY sr; FVECT h; double rv[2]; double d, sinp, cosp; + int niter; register int i; /* compute reflection */ if ((np->specfl & (SP_REFL|SP_RBLT)) == SP_REFL && rayorigin(&sr, r, SPECULAR, np->rspec) == 0) { dimlist[ndims++] = (int)np->mp; - d = urand(ilhash(dimlist,ndims)+samplendx); - multisamp(rv, 2, d); - d = 2.0*PI * rv[0]; - cosp = np->u_alpha * cos(d); - sinp = np->v_alpha * sin(d); - d = sqrt(cosp*cosp + sinp*sinp); - cosp /= d; - sinp /= d; - rv[1] = 1.0 - specjitter*rv[1]; - if (rv[1] <= FTINY) - d = 1.0; - else - d = sqrt(-log(rv[1]) / - (cosp*cosp/(np->u_alpha*np->u_alpha) + - sinp*sinp/(np->v_alpha*np->v_alpha))); - for (i = 0; i < 3; i++) - h[i] = np->pnorm[i] + - d*(cosp*np->u[i] + sinp*np->v[i]); - d = -2.0 * DOT(h, r->rdir) / (1.0 + d*d); - for (i = 0; i < 3; i++) - sr.rdir[i] = r->rdir[i] + d*h[i]; - if (DOT(sr.rdir, r->ron) <= FTINY) /* penetration? */ - VCOPY(sr.rdir, np->vrefl); /* jitter no good */ - rayvalue(&sr); - multcolor(sr.rcol, np->scolor); - addcolor(r->rcol, sr.rcol); + for (niter = 0; niter < MAXITER; niter++) { + if (niter) + d = frandom(); + else + d = urand(ilhash(dimlist,ndims)+samplendx); + multisamp(rv, 2, d); + d = 2.0*PI * rv[0]; + cosp = tcos(d) * np->u_alpha; + sinp = tsin(d) * np->v_alpha; + d = sqrt(cosp*cosp + sinp*sinp); + cosp /= d; + sinp /= d; + rv[1] = 1.0 - specjitter*rv[1]; + if (rv[1] <= FTINY) + d = 1.0; + else + d = sqrt(-log(rv[1]) / + (cosp*cosp/(np->u_alpha*np->u_alpha) + + sinp*sinp/(np->v_alpha*np->v_alpha))); + for (i = 0; i < 3; i++) + h[i] = np->pnorm[i] + + d*(cosp*np->u[i] + sinp*np->v[i]); + d = -2.0 * DOT(h, r->rdir) / (1.0 + d*d); + for (i = 0; i < 3; i++) + sr.rdir[i] = r->rdir[i] + d*h[i]; + if (DOT(sr.rdir, r->ron) > FTINY) { + rayvalue(&sr); + multcolor(sr.rcol, np->scolor); + addcolor(r->rcol, sr.rcol); + break; + } + } ndims--; } /* compute transmission */ if ((np->specfl & (SP_TRAN|SP_TBLT)) == SP_TRAN && rayorigin(&sr, r, SPECULAR, np->tspec) == 0) { dimlist[ndims++] = (int)np->mp; - d = urand(ilhash(dimlist,ndims)+1823+samplendx); - multisamp(rv, 2, d); - d = 2.0*PI * rv[0]; - cosp = cos(d); - sinp = sin(d); - rv[1] = 1.0 - specjitter*rv[1]; - if (rv[1] <= FTINY) - d = 1.0; - else - d = sqrt(-log(rv[1]) / - (cosp*cosp*4./(np->u_alpha*np->u_alpha) + - sinp*sinp*4./(np->v_alpha*np->v_alpha))); - for (i = 0; i < 3; i++) - sr.rdir[i] = np->prdir[i] + - d*(cosp*np->u[i] + sinp*np->v[i]); - if (DOT(sr.rdir, r->ron) < -FTINY) - normalize(sr.rdir); /* OK, normalize */ - else - VCOPY(sr.rdir, np->prdir); /* else no jitter */ - rayvalue(&sr); - scalecolor(sr.rcol, np->tspec); - multcolor(sr.rcol, np->mcolor); /* modify by color */ - addcolor(r->rcol, sr.rcol); + for (niter = 0; niter < MAXITER; niter++) { + if (niter) + d = frandom(); + else + d = urand(ilhash(dimlist,ndims)+1823+samplendx); + multisamp(rv, 2, d); + d = 2.0*PI * rv[0]; + cosp = tcos(d) * np->u_alpha; + sinp = tsin(d) * np->v_alpha; + d = sqrt(cosp*cosp + sinp*sinp); + cosp /= d; + sinp /= d; + rv[1] = 1.0 - specjitter*rv[1]; + if (rv[1] <= FTINY) + d = 1.0; + else + d = sqrt(-log(rv[1]) / + (cosp*cosp/(np->u_alpha*np->u_alpha) + + sinp*sinp/(np->v_alpha*np->v_alpha))); + for (i = 0; i < 3; i++) + sr.rdir[i] = np->prdir[i] + + d*(cosp*np->u[i] + sinp*np->v[i]); + if (DOT(sr.rdir, r->ron) < -FTINY) { + normalize(sr.rdir); /* OK, normalize */ + rayvalue(&sr); + scalecolor(sr.rcol, np->tspec); + multcolor(sr.rcol, np->mcolor); /* modify */ + addcolor(r->rcol, sr.rcol); + break; + } + } ndims--; } }