| 1 |
– |
/* Copyright (c) 1986 Regents of the University of California */ |
| 2 |
– |
|
| 1 |
|
#ifndef lint |
| 2 |
< |
static char SCCSid[] = "$SunId$ LBL"; |
| 2 |
> |
static const char RCSid[] = "$Id$"; |
| 3 |
|
#endif |
| 6 |
– |
|
| 4 |
|
/* |
| 5 |
|
* dielectric.c - shading function for transparent materials. |
| 9 |
– |
* |
| 10 |
– |
* 9/6/85 |
| 6 |
|
*/ |
| 7 |
|
|
| 8 |
< |
#include "ray.h" |
| 8 |
> |
#include "copyright.h" |
| 9 |
|
|
| 10 |
+ |
#include "ray.h" |
| 11 |
|
#include "otypes.h" |
| 12 |
+ |
#include "rtotypes.h" |
| 13 |
|
|
| 14 |
|
#ifdef DISPERSE |
| 15 |
|
#include "source.h" |
| 16 |
+ |
static int disperse(OBJREC *m,RAY *r,FVECT vt,double tr,COLOR cet,COLOR abt); |
| 17 |
+ |
static int lambda(OBJREC *m, FVECT v2, FVECT dv, FVECT lr); |
| 18 |
|
#endif |
| 19 |
|
|
| 20 |
+ |
static double mylog(double x); |
| 21 |
+ |
|
| 22 |
+ |
|
| 23 |
|
/* |
| 24 |
|
* Explicit calculations for Fresnel's equation are performed, |
| 25 |
|
* but only one square root computation is necessary. |
| 51 |
|
#define MINCOS 0.997 /* minimum dot product for dispersion */ |
| 52 |
|
|
| 53 |
|
|
| 54 |
< |
m_dielectric(m, r) /* color a ray which hit something transparent */ |
| 55 |
< |
OBJREC *m; |
| 56 |
< |
register RAY *r; |
| 54 |
> |
static double |
| 55 |
> |
mylog( /* special log for extinction coefficients */ |
| 56 |
> |
double x |
| 57 |
> |
) |
| 58 |
|
{ |
| 59 |
< |
double sqrt(), pow(); |
| 59 |
> |
if (x < 1e-40) |
| 60 |
> |
return(-100.); |
| 61 |
> |
if (x >= 1.) |
| 62 |
> |
return(0.); |
| 63 |
> |
return(log(x)); |
| 64 |
> |
} |
| 65 |
> |
|
| 66 |
> |
|
| 67 |
> |
extern int |
| 68 |
> |
m_dielectric( /* color a ray which hit a dielectric interface */ |
| 69 |
> |
OBJREC *m, |
| 70 |
> |
register RAY *r |
| 71 |
> |
) |
| 72 |
> |
{ |
| 73 |
|
double cos1, cos2, nratio; |
| 74 |
< |
COLOR mcolor; |
| 75 |
< |
double mabsorp; |
| 74 |
> |
COLOR ctrans; |
| 75 |
> |
COLOR talb; |
| 76 |
> |
int hastexture; |
| 77 |
> |
double transdist, transtest=0; |
| 78 |
> |
double mirdist, mirtest=0; |
| 79 |
> |
int flatsurface; |
| 80 |
|
double refl, trans; |
| 81 |
|
FVECT dnorm; |
| 82 |
|
double d1, d2; |
| 86 |
|
if (m->oargs.nfargs != (m->otype==MAT_DIELECTRIC ? 5 : 8)) |
| 87 |
|
objerror(m, USER, "bad arguments"); |
| 88 |
|
|
| 69 |
– |
r->rt = r->rot; /* just use ray length */ |
| 70 |
– |
|
| 89 |
|
raytexture(r, m->omod); /* get modifiers */ |
| 90 |
|
|
| 91 |
< |
cos1 = raynormal(dnorm, r); /* cosine of theta1 */ |
| 91 |
> |
if ( (hastexture = DOT(r->pert,r->pert) > FTINY*FTINY) ) |
| 92 |
> |
cos1 = raynormal(dnorm, r); /* perturb normal */ |
| 93 |
> |
else { |
| 94 |
> |
VCOPY(dnorm, r->ron); |
| 95 |
> |
cos1 = r->rod; |
| 96 |
> |
} |
| 97 |
> |
flatsurface = !hastexture && r->ro != NULL && isflat(r->ro->otype); |
| 98 |
> |
|
| 99 |
|
/* index of refraction */ |
| 100 |
|
if (m->otype == MAT_DIELECTRIC) |
| 101 |
|
nratio = m->oargs.farg[3] + m->oargs.farg[4]/MLAMBDA; |
| 103 |
|
nratio = m->oargs.farg[3] / m->oargs.farg[7]; |
| 104 |
|
|
| 105 |
|
if (cos1 < 0.0) { /* inside */ |
| 106 |
+ |
hastexture = -hastexture; |
| 107 |
|
cos1 = -cos1; |
| 108 |
|
dnorm[0] = -dnorm[0]; |
| 109 |
|
dnorm[1] = -dnorm[1]; |
| 110 |
|
dnorm[2] = -dnorm[2]; |
| 111 |
< |
setcolor(mcolor, pow(m->oargs.farg[0], r->rot), |
| 112 |
< |
pow(m->oargs.farg[1], r->rot), |
| 113 |
< |
pow(m->oargs.farg[2], r->rot)); |
| 111 |
> |
setcolor(r->cext, -mylog(m->oargs.farg[0]*colval(r->pcol,RED)), |
| 112 |
> |
-mylog(m->oargs.farg[1]*colval(r->pcol,GRN)), |
| 113 |
> |
-mylog(m->oargs.farg[2]*colval(r->pcol,BLU))); |
| 114 |
> |
setcolor(r->albedo, 0., 0., 0.); |
| 115 |
> |
r->gecc = 0.; |
| 116 |
> |
if (m->otype == MAT_INTERFACE) { |
| 117 |
> |
setcolor(ctrans, |
| 118 |
> |
-mylog(m->oargs.farg[4]*colval(r->pcol,RED)), |
| 119 |
> |
-mylog(m->oargs.farg[5]*colval(r->pcol,GRN)), |
| 120 |
> |
-mylog(m->oargs.farg[6]*colval(r->pcol,BLU))); |
| 121 |
> |
setcolor(talb, 0., 0., 0.); |
| 122 |
> |
} else { |
| 123 |
> |
copycolor(ctrans, cextinction); |
| 124 |
> |
copycolor(talb, salbedo); |
| 125 |
> |
} |
| 126 |
|
} else { /* outside */ |
| 127 |
|
nratio = 1.0 / nratio; |
| 128 |
< |
if (m->otype == MAT_INTERFACE) |
| 129 |
< |
setcolor(mcolor, pow(m->oargs.farg[4], r->rot), |
| 130 |
< |
pow(m->oargs.farg[5], r->rot), |
| 131 |
< |
pow(m->oargs.farg[6], r->rot)); |
| 132 |
< |
else |
| 133 |
< |
setcolor(mcolor, 1.0, 1.0, 1.0); |
| 128 |
> |
|
| 129 |
> |
setcolor(ctrans, -mylog(m->oargs.farg[0]*colval(r->pcol,RED)), |
| 130 |
> |
-mylog(m->oargs.farg[1]*colval(r->pcol,GRN)), |
| 131 |
> |
-mylog(m->oargs.farg[2]*colval(r->pcol,BLU))); |
| 132 |
> |
setcolor(talb, 0., 0., 0.); |
| 133 |
> |
if (m->otype == MAT_INTERFACE) { |
| 134 |
> |
setcolor(r->cext, |
| 135 |
> |
-mylog(m->oargs.farg[4]*colval(r->pcol,RED)), |
| 136 |
> |
-mylog(m->oargs.farg[5]*colval(r->pcol,GRN)), |
| 137 |
> |
-mylog(m->oargs.farg[6]*colval(r->pcol,BLU))); |
| 138 |
> |
setcolor(r->albedo, 0., 0., 0.); |
| 139 |
> |
r->gecc = 0.; |
| 140 |
> |
} |
| 141 |
|
} |
| 97 |
– |
mabsorp = bright(mcolor); |
| 142 |
|
|
| 143 |
|
d2 = 1.0 - nratio*nratio*(1.0 - cos1*cos1); /* compute cos theta2 */ |
| 144 |
|
|
| 159 |
|
d1 = (d1 - d2) / (d1 + d2); |
| 160 |
|
refl += d1 * d1; |
| 161 |
|
|
| 162 |
< |
refl /= 2.0; |
| 162 |
> |
refl *= 0.5; |
| 163 |
|
trans = 1.0 - refl; |
| 164 |
|
|
| 165 |
< |
if (rayorigin(&p, r, REFRACTED, mabsorp*trans) == 0) { |
| 165 |
> |
trans *= nratio*nratio; /* solid angle ratio */ |
| 166 |
|
|
| 167 |
+ |
if (rayorigin(&p, r, REFRACTED, trans) == 0) { |
| 168 |
+ |
|
| 169 |
|
/* compute refracted ray */ |
| 170 |
|
d1 = nratio*cos1 - cos2; |
| 171 |
|
for (i = 0; i < 3; i++) |
| 172 |
|
p.rdir[i] = nratio*r->rdir[i] + d1*dnorm[i]; |
| 173 |
< |
|
| 173 |
> |
/* accidental reflection? */ |
| 174 |
> |
if (hastexture && |
| 175 |
> |
DOT(p.rdir,r->ron)*hastexture >= -FTINY) { |
| 176 |
> |
d1 *= (double)hastexture; |
| 177 |
> |
for (i = 0; i < 3; i++) /* ignore texture */ |
| 178 |
> |
p.rdir[i] = nratio*r->rdir[i] + |
| 179 |
> |
d1*r->ron[i]; |
| 180 |
> |
normalize(p.rdir); /* not exact */ |
| 181 |
> |
} |
| 182 |
|
#ifdef DISPERSE |
| 183 |
|
if (m->otype != MAT_DIELECTRIC |
| 184 |
|
|| r->rod > 0.0 |
| 185 |
|
|| r->crtype & SHADOW |
| 186 |
< |
|| directinvis |
| 186 |
> |
|| !directvis |
| 187 |
|
|| m->oargs.farg[4] == 0.0 |
| 188 |
< |
|| !disperse(m, r, p.rdir, trans)) |
| 188 |
> |
|| !disperse(m, r, p.rdir, |
| 189 |
> |
trans, ctrans, talb)) |
| 190 |
|
#endif |
| 191 |
|
{ |
| 192 |
+ |
copycolor(p.cext, ctrans); |
| 193 |
+ |
copycolor(p.albedo, talb); |
| 194 |
|
rayvalue(&p); |
| 138 |
– |
multcolor(mcolor, r->pcol); /* modify */ |
| 195 |
|
scalecolor(p.rcol, trans); |
| 196 |
|
addcolor(r->rcol, p.rcol); |
| 197 |
+ |
/* virtual distance */ |
| 198 |
+ |
if (flatsurface || |
| 199 |
+ |
(1.-FTINY <= nratio && |
| 200 |
+ |
nratio <= 1.+FTINY)) { |
| 201 |
+ |
transtest = 2*bright(p.rcol); |
| 202 |
+ |
transdist = r->rot + p.rt; |
| 203 |
+ |
} |
| 204 |
|
} |
| 205 |
|
} |
| 206 |
|
} |
| 207 |
|
|
| 208 |
|
if (!(r->crtype & SHADOW) && |
| 209 |
< |
rayorigin(&p, r, REFLECTED, mabsorp*refl) == 0) { |
| 209 |
> |
rayorigin(&p, r, REFLECTED, refl) == 0) { |
| 210 |
|
|
| 211 |
|
/* compute reflected ray */ |
| 212 |
|
for (i = 0; i < 3; i++) |
| 213 |
|
p.rdir[i] = r->rdir[i] + 2.0*cos1*dnorm[i]; |
| 214 |
+ |
/* accidental penetration? */ |
| 215 |
+ |
if (hastexture && DOT(p.rdir,r->ron)*hastexture <= FTINY) |
| 216 |
+ |
for (i = 0; i < 3; i++) /* ignore texture */ |
| 217 |
+ |
p.rdir[i] = r->rdir[i] + 2.0*r->rod*r->ron[i]; |
| 218 |
|
|
| 219 |
|
rayvalue(&p); /* reflected ray value */ |
| 220 |
|
|
| 221 |
|
scalecolor(p.rcol, refl); /* color contribution */ |
| 222 |
|
addcolor(r->rcol, p.rcol); |
| 223 |
+ |
/* virtual distance */ |
| 224 |
+ |
if (flatsurface) { |
| 225 |
+ |
mirtest = 2*bright(p.rcol); |
| 226 |
+ |
mirdist = r->rot + p.rt; |
| 227 |
+ |
} |
| 228 |
|
} |
| 229 |
< |
|
| 230 |
< |
multcolor(r->rcol, mcolor); /* multiply by transmittance */ |
| 229 |
> |
/* check distance to return */ |
| 230 |
> |
d1 = bright(r->rcol); |
| 231 |
> |
if (transtest > d1) |
| 232 |
> |
r->rt = transdist; |
| 233 |
> |
else if (mirtest > d1) |
| 234 |
> |
r->rt = mirdist; |
| 235 |
> |
/* rayvalue() computes absorption */ |
| 236 |
> |
return(1); |
| 237 |
|
} |
| 238 |
|
|
| 239 |
|
|
| 240 |
|
#ifdef DISPERSE |
| 241 |
|
|
| 242 |
< |
static |
| 243 |
< |
disperse(m, r, vt, tr) /* check light sources for dispersion */ |
| 244 |
< |
OBJREC *m; |
| 245 |
< |
RAY *r; |
| 246 |
< |
FVECT vt; |
| 247 |
< |
double tr; |
| 242 |
> |
static int |
| 243 |
> |
disperse( /* check light sources for dispersion */ |
| 244 |
> |
OBJREC *m, |
| 245 |
> |
RAY *r, |
| 246 |
> |
FVECT vt, |
| 247 |
> |
double tr, |
| 248 |
> |
COLOR cet, |
| 249 |
> |
COLOR abt |
| 250 |
> |
) |
| 251 |
|
{ |
| 171 |
– |
double sqrt(); |
| 252 |
|
RAY sray, *entray; |
| 253 |
|
FVECT v1, v2, n1, n2; |
| 254 |
|
FVECT dv, v2Xdv; |
| 333 |
|
if (l1 > MAXLAMBDA || l1 < MINLAMBDA) /* not visible */ |
| 334 |
|
continue; |
| 335 |
|
/* trace source ray */ |
| 336 |
+ |
copycolor(sray.cext, cet); |
| 337 |
+ |
copycolor(sray.albedo, abt); |
| 338 |
|
normalize(sray.rdir); |
| 339 |
|
rayvalue(&sray); |
| 340 |
|
if (bright(sray.rcol) <= FTINY) /* missed it */ |
| 378 |
|
|
| 379 |
|
|
| 380 |
|
static int |
| 381 |
< |
lambda(m, v2, dv, lr) /* compute lambda for material */ |
| 382 |
< |
register OBJREC *m; |
| 383 |
< |
FVECT v2, dv, lr; |
| 381 |
> |
lambda( /* compute lambda for material */ |
| 382 |
> |
register OBJREC *m, |
| 383 |
> |
FVECT v2, |
| 384 |
> |
FVECT dv, |
| 385 |
> |
FVECT lr |
| 386 |
> |
) |
| 387 |
|
{ |
| 388 |
|
FVECT lrXdv, v2Xlr; |
| 389 |
|
double dtmp, denom; |
