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; |
88 |
|
|
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 |
|
} |
95 |
– |
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 |
+ |
setcolor(p.rcoef, trans, trans, trans); |
168 |
+ |
|
169 |
+ |
if (rayorigin(&p, REFRACTED, r, p.rcoef) == 0) { |
170 |
+ |
|
171 |
|
/* compute refracted ray */ |
172 |
|
d1 = nratio*cos1 - cos2; |
173 |
|
for (i = 0; i < 3; i++) |
174 |
|
p.rdir[i] = nratio*r->rdir[i] + d1*dnorm[i]; |
175 |
< |
|
175 |
> |
/* accidental reflection? */ |
176 |
> |
if (hastexture && |
177 |
> |
DOT(p.rdir,r->ron)*hastexture >= -FTINY) { |
178 |
> |
d1 *= (double)hastexture; |
179 |
> |
for (i = 0; i < 3; i++) /* ignore texture */ |
180 |
> |
p.rdir[i] = nratio*r->rdir[i] + |
181 |
> |
d1*r->ron[i]; |
182 |
> |
normalize(p.rdir); /* not exact */ |
183 |
> |
} else |
184 |
> |
checknorm(p.rdir); |
185 |
|
#ifdef DISPERSE |
186 |
|
if (m->otype != MAT_DIELECTRIC |
187 |
|
|| r->rod > 0.0 |
188 |
|
|| r->crtype & SHADOW |
189 |
+ |
|| !directvis |
190 |
|
|| m->oargs.farg[4] == 0.0 |
191 |
< |
|| !disperse(m, r, p.rdir, trans)) |
191 |
> |
|| !disperse(m, r, p.rdir, |
192 |
> |
trans, ctrans, talb)) |
193 |
|
#endif |
194 |
|
{ |
195 |
+ |
copycolor(p.cext, ctrans); |
196 |
+ |
copycolor(p.albedo, talb); |
197 |
|
rayvalue(&p); |
198 |
< |
multcolor(mcolor, r->pcol); /* modify */ |
136 |
< |
scalecolor(p.rcol, trans); |
198 |
> |
multcolor(p.rcol, p.rcoef); |
199 |
|
addcolor(r->rcol, p.rcol); |
200 |
< |
r->rt = r->rot + p.rt; |
200 |
> |
/* virtual distance */ |
201 |
> |
if (flatsurface || |
202 |
> |
(1.-FTINY <= nratio && |
203 |
> |
nratio <= 1.+FTINY)) { |
204 |
> |
transtest = 2*bright(p.rcol); |
205 |
> |
transdist = r->rot + p.rt; |
206 |
> |
} |
207 |
|
} |
208 |
|
} |
209 |
|
} |
210 |
< |
|
210 |
> |
setcolor(p.rcoef, refl, refl, refl); |
211 |
> |
|
212 |
|
if (!(r->crtype & SHADOW) && |
213 |
< |
rayorigin(&p, r, REFLECTED, mabsorp*refl) == 0) { |
213 |
> |
rayorigin(&p, REFLECTED, r, p.rcoef) == 0) { |
214 |
|
|
215 |
|
/* compute reflected ray */ |
216 |
< |
for (i = 0; i < 3; i++) |
217 |
< |
p.rdir[i] = r->rdir[i] + 2.0*cos1*dnorm[i]; |
218 |
< |
|
216 |
> |
VSUM(p.rdir, r->rdir, dnorm, 2.*cos1); |
217 |
> |
/* accidental penetration? */ |
218 |
> |
if (hastexture && DOT(p.rdir,r->ron)*hastexture <= FTINY) |
219 |
> |
VSUM(p.rdir, r->rdir, r->ron, 2.*r->rod); |
220 |
> |
checknorm(p.rdir); |
221 |
|
rayvalue(&p); /* reflected ray value */ |
222 |
|
|
223 |
< |
scalecolor(p.rcol, refl); /* color contribution */ |
223 |
> |
multcolor(p.rcol, p.rcoef); /* color contribution */ |
224 |
|
addcolor(r->rcol, p.rcol); |
225 |
< |
if (refl > trans) |
226 |
< |
r->rt = r->rot + p.rt; |
225 |
> |
/* virtual distance */ |
226 |
> |
if (flatsurface) { |
227 |
> |
mirtest = 2*bright(p.rcol); |
228 |
> |
mirdist = r->rot + p.rt; |
229 |
> |
} |
230 |
|
} |
231 |
< |
|
232 |
< |
multcolor(r->rcol, mcolor); /* multiply by transmittance */ |
231 |
> |
/* check distance to return */ |
232 |
> |
d1 = bright(r->rcol); |
233 |
> |
if (transtest > d1) |
234 |
> |
r->rt = transdist; |
235 |
> |
else if (mirtest > d1) |
236 |
> |
r->rt = mirdist; |
237 |
> |
/* rayvalue() computes absorption */ |
238 |
> |
return(1); |
239 |
|
} |
240 |
|
|
241 |
|
|
242 |
|
#ifdef DISPERSE |
243 |
|
|
244 |
< |
static |
245 |
< |
disperse(m, r, vt, tr) /* check light sources for dispersion */ |
246 |
< |
OBJREC *m; |
247 |
< |
RAY *r; |
248 |
< |
FVECT vt; |
249 |
< |
double tr; |
244 |
> |
static int |
245 |
> |
disperse( /* check light sources for dispersion */ |
246 |
> |
OBJREC *m, |
247 |
> |
RAY *r, |
248 |
> |
FVECT vt, |
249 |
> |
double tr, |
250 |
> |
COLOR cet, |
251 |
> |
COLOR abt |
252 |
> |
) |
253 |
|
{ |
254 |
< |
double sqrt(); |
255 |
< |
RAY sray, *entray; |
254 |
> |
RAY sray; |
255 |
> |
const RAY *entray; |
256 |
|
FVECT v1, v2, n1, n2; |
257 |
|
FVECT dv, v2Xdv; |
258 |
|
double v2Xdvv2Xdv; |
259 |
< |
int sn, success = 0; |
260 |
< |
double omega; |
259 |
> |
int success = 0; |
260 |
> |
SRCINDEX si; |
261 |
|
FVECT vtmp1, vtmp2; |
262 |
|
double dtmp1, dtmp2; |
263 |
|
int l1, l2; |
307 |
|
VCOPY(n2, r->ron); |
308 |
|
|
309 |
|
/* first order dispersion approx. */ |
310 |
< |
dtmp1 = DOT(n1, v1); |
311 |
< |
dtmp2 = DOT(n2, v2); |
310 |
> |
dtmp1 = 1./DOT(n1, v1); |
311 |
> |
dtmp2 = 1./DOT(n2, v2); |
312 |
|
for (i = 0; i < 3; i++) |
313 |
< |
dv[i] = v1[i] + v2[i] - n1[i]/dtmp1 - n2[i]/dtmp2; |
313 |
> |
dv[i] = v1[i] + v2[i] - n1[i]*dtmp1 - n2[i]*dtmp2; |
314 |
|
|
315 |
|
if (DOT(dv, dv) <= FTINY) /* null effect */ |
316 |
|
return(0); |
319 |
|
v2Xdvv2Xdv = DOT(v2Xdv, v2Xdv); |
320 |
|
|
321 |
|
/* check sources */ |
322 |
< |
for (sn = 0; sn < nsources; sn++) { |
322 |
> |
initsrcindex(&si); |
323 |
> |
while (srcray(&sray, r, &si)) { |
324 |
|
|
325 |
< |
if ((omega = srcray(&sray, r, sn)) == 0.0 || |
242 |
< |
DOT(sray.rdir, v2) < MINCOS) |
325 |
> |
if (DOT(sray.rdir, v2) < MINCOS) |
326 |
|
continue; /* bad source */ |
244 |
– |
|
327 |
|
/* adjust source ray */ |
328 |
|
|
329 |
|
dtmp1 = DOT(v2Xdv, sray.rdir) / v2Xdvv2Xdv; |
336 |
|
if (l1 > MAXLAMBDA || l1 < MINLAMBDA) /* not visible */ |
337 |
|
continue; |
338 |
|
/* trace source ray */ |
339 |
+ |
copycolor(sray.cext, cet); |
340 |
+ |
copycolor(sray.albedo, abt); |
341 |
|
normalize(sray.rdir); |
342 |
|
rayvalue(&sray); |
343 |
|
if (bright(sray.rcol) <= FTINY) /* missed it */ |
350 |
|
*/ |
351 |
|
|
352 |
|
fcross(vtmp1, v2Xdv, sray.rdir); |
353 |
< |
dtmp1 = sqrt(omega / v2Xdvv2Xdv / PI); |
353 |
> |
dtmp1 = sqrt(si.dom / v2Xdvv2Xdv / PI); |
354 |
|
|
355 |
|
/* compute first ray */ |
356 |
< |
for (i = 0; i < 3; i++) |
273 |
< |
vtmp2[i] = sray.rdir[i] + dtmp1*vtmp1[i]; |
356 |
> |
VSUM(vtmp2, sray.rdir, vtmp1, dtmp1); |
357 |
|
|
358 |
|
l1 = lambda(m, v2, dv, vtmp2); /* first lambda */ |
359 |
|
if (l1 < 0) |
360 |
|
continue; |
361 |
|
/* compute second ray */ |
362 |
< |
for (i = 0; i < 3; i++) |
280 |
< |
vtmp2[i] = sray.rdir[i] - dtmp1*vtmp1[i]; |
362 |
> |
VSUM(vtmp2, sray.rdir, vtmp1, -dtmp1); |
363 |
|
|
364 |
|
l2 = lambda(m, v2, dv, vtmp2); /* second lambda */ |
365 |
|
if (l2 < 0) |
379 |
|
|
380 |
|
|
381 |
|
static int |
382 |
< |
lambda(m, v2, dv, lr) /* compute lambda for material */ |
383 |
< |
register OBJREC *m; |
384 |
< |
FVECT v2, dv, lr; |
382 |
> |
lambda( /* compute lambda for material */ |
383 |
> |
register OBJREC *m, |
384 |
> |
FVECT v2, |
385 |
> |
FVECT dv, |
386 |
> |
FVECT lr |
387 |
> |
) |
388 |
|
{ |
389 |
|
FVECT lrXdv, v2Xlr; |
390 |
|
double dtmp, denom; |
392 |
|
|
393 |
|
fcross(lrXdv, lr, dv); |
394 |
|
for (i = 0; i < 3; i++) |
395 |
< |
if (lrXdv[i] > FTINY || lrXdv[i] < -FTINY) |
395 |
> |
if ((lrXdv[i] > FTINY) | (lrXdv[i] < -FTINY)) |
396 |
|
break; |
397 |
|
if (i >= 3) |
398 |
|
return(-1); |