1 |
greg |
1.1 |
#ifndef lint |
2 |
greg |
2.53 |
static const char RCSid[] = "$Id: normal.c,v 2.52 2010/05/07 15:44:52 greg Exp $"; |
3 |
greg |
1.1 |
#endif |
4 |
|
|
/* |
5 |
|
|
* normal.c - shading function for normal materials. |
6 |
|
|
* |
7 |
|
|
* 8/19/85 |
8 |
|
|
* 12/19/85 - added stuff for metals. |
9 |
|
|
* 6/26/87 - improved specular model. |
10 |
|
|
* 9/28/87 - added model for translucent materials. |
11 |
greg |
2.2 |
* Later changes described in delta comments. |
12 |
greg |
1.1 |
*/ |
13 |
|
|
|
14 |
greg |
2.39 |
#include "copyright.h" |
15 |
greg |
2.38 |
|
16 |
greg |
1.1 |
#include "ray.h" |
17 |
greg |
2.46 |
#include "ambient.h" |
18 |
schorsch |
2.47 |
#include "source.h" |
19 |
greg |
1.1 |
#include "otypes.h" |
20 |
schorsch |
2.47 |
#include "rtotypes.h" |
21 |
greg |
2.2 |
#include "random.h" |
22 |
|
|
|
23 |
greg |
2.34 |
#ifndef MAXITER |
24 |
|
|
#define MAXITER 10 /* maximum # specular ray attempts */ |
25 |
|
|
#endif |
26 |
greg |
2.38 |
/* estimate of Fresnel function */ |
27 |
greg |
2.44 |
#define FRESNE(ci) (exp(-5.85*(ci)) - 0.00287989916) |
28 |
greg |
2.51 |
#define FRESTHRESH 0.017999 /* minimum specularity for approx. */ |
29 |
greg |
2.34 |
|
30 |
greg |
2.24 |
|
31 |
greg |
1.1 |
/* |
32 |
greg |
2.22 |
* This routine implements the isotropic Gaussian |
33 |
|
|
* model described by Ward in Siggraph `92 article. |
34 |
greg |
1.1 |
* We orient the surface towards the incoming ray, so a single |
35 |
|
|
* surface can be used to represent an infinitely thin object. |
36 |
|
|
* |
37 |
|
|
* Arguments for MAT_PLASTIC and MAT_METAL are: |
38 |
|
|
* red grn blu specular-frac. facet-slope |
39 |
|
|
* |
40 |
|
|
* Arguments for MAT_TRANS are: |
41 |
|
|
* red grn blu rspec rough trans tspec |
42 |
|
|
*/ |
43 |
|
|
|
44 |
greg |
2.2 |
/* specularity flags */ |
45 |
|
|
#define SP_REFL 01 /* has reflected specular component */ |
46 |
|
|
#define SP_TRAN 02 /* has transmitted specular */ |
47 |
greg |
2.11 |
#define SP_PURE 04 /* purely specular (zero roughness) */ |
48 |
|
|
#define SP_FLAT 010 /* flat reflecting surface */ |
49 |
|
|
#define SP_RBLT 020 /* reflection below sample threshold */ |
50 |
|
|
#define SP_TBLT 040 /* transmission below threshold */ |
51 |
greg |
1.1 |
|
52 |
greg |
1.3 |
typedef struct { |
53 |
|
|
OBJREC *mp; /* material pointer */ |
54 |
greg |
2.16 |
RAY *rp; /* ray pointer */ |
55 |
greg |
2.2 |
short specfl; /* specularity flags, defined above */ |
56 |
greg |
1.1 |
COLOR mcolor; /* color of this material */ |
57 |
|
|
COLOR scolor; /* color of specular component */ |
58 |
|
|
FVECT vrefl; /* vector in direction of reflected ray */ |
59 |
greg |
1.14 |
FVECT prdir; /* vector in transmitted direction */ |
60 |
greg |
2.2 |
double alpha2; /* roughness squared */ |
61 |
greg |
1.1 |
double rdiff, rspec; /* reflected specular, diffuse */ |
62 |
|
|
double trans; /* transmissivity */ |
63 |
|
|
double tdiff, tspec; /* transmitted specular, diffuse */ |
64 |
|
|
FVECT pnorm; /* perturbed surface normal */ |
65 |
|
|
double pdot; /* perturbed dot product */ |
66 |
greg |
1.3 |
} NORMDAT; /* normal material data */ |
67 |
|
|
|
68 |
schorsch |
2.47 |
static srcdirf_t dirnorm; |
69 |
|
|
static void gaussamp(RAY *r, NORMDAT *np); |
70 |
|
|
|
71 |
greg |
1.3 |
|
72 |
greg |
2.38 |
static void |
73 |
schorsch |
2.47 |
dirnorm( /* compute source contribution */ |
74 |
|
|
COLOR cval, /* returned coefficient */ |
75 |
|
|
void *nnp, /* material data */ |
76 |
|
|
FVECT ldir, /* light source direction */ |
77 |
|
|
double omega /* light source size */ |
78 |
|
|
) |
79 |
greg |
1.3 |
{ |
80 |
schorsch |
2.47 |
register NORMDAT *np = nnp; |
81 |
greg |
1.1 |
double ldot; |
82 |
greg |
2.49 |
double lrdiff, ltdiff; |
83 |
greg |
2.16 |
double dtmp, d2; |
84 |
|
|
FVECT vtmp; |
85 |
greg |
1.3 |
COLOR ctmp; |
86 |
|
|
|
87 |
|
|
setcolor(cval, 0.0, 0.0, 0.0); |
88 |
|
|
|
89 |
|
|
ldot = DOT(np->pnorm, ldir); |
90 |
|
|
|
91 |
|
|
if (ldot < 0.0 ? np->trans <= FTINY : np->trans >= 1.0-FTINY) |
92 |
|
|
return; /* wrong side */ |
93 |
|
|
|
94 |
greg |
2.38 |
/* Fresnel estimate */ |
95 |
greg |
2.49 |
lrdiff = np->rdiff; |
96 |
|
|
ltdiff = np->tdiff; |
97 |
greg |
2.51 |
if (np->specfl & SP_PURE && np->rspec >= FRESTHRESH && |
98 |
greg |
2.49 |
(lrdiff > FTINY) | (ltdiff > FTINY)) { |
99 |
|
|
dtmp = 1. - FRESNE(fabs(ldot)); |
100 |
|
|
lrdiff *= dtmp; |
101 |
|
|
ltdiff *= dtmp; |
102 |
|
|
} |
103 |
greg |
2.38 |
|
104 |
greg |
2.49 |
if (ldot > FTINY && lrdiff > FTINY) { |
105 |
greg |
1.3 |
/* |
106 |
greg |
1.4 |
* Compute and add diffuse reflected component to returned |
107 |
|
|
* color. The diffuse reflected component will always be |
108 |
|
|
* modified by the color of the material. |
109 |
greg |
1.3 |
*/ |
110 |
|
|
copycolor(ctmp, np->mcolor); |
111 |
greg |
2.49 |
dtmp = ldot * omega * lrdiff * (1.0/PI); |
112 |
greg |
1.3 |
scalecolor(ctmp, dtmp); |
113 |
|
|
addcolor(cval, ctmp); |
114 |
|
|
} |
115 |
greg |
2.2 |
if (ldot > FTINY && (np->specfl&(SP_REFL|SP_PURE)) == SP_REFL) { |
116 |
greg |
1.3 |
/* |
117 |
|
|
* Compute specular reflection coefficient using |
118 |
|
|
* gaussian distribution model. |
119 |
|
|
*/ |
120 |
greg |
2.3 |
/* roughness */ |
121 |
greg |
2.16 |
dtmp = np->alpha2; |
122 |
greg |
2.3 |
/* + source if flat */ |
123 |
|
|
if (np->specfl & SP_FLAT) |
124 |
greg |
2.48 |
dtmp += omega * (0.25/PI); |
125 |
greg |
2.23 |
/* half vector */ |
126 |
greg |
2.18 |
vtmp[0] = ldir[0] - np->rp->rdir[0]; |
127 |
|
|
vtmp[1] = ldir[1] - np->rp->rdir[1]; |
128 |
|
|
vtmp[2] = ldir[2] - np->rp->rdir[2]; |
129 |
greg |
2.16 |
d2 = DOT(vtmp, np->pnorm); |
130 |
greg |
2.23 |
d2 *= d2; |
131 |
|
|
d2 = (DOT(vtmp,vtmp) - d2) / d2; |
132 |
greg |
1.3 |
/* gaussian */ |
133 |
greg |
2.48 |
dtmp = exp(-d2/dtmp)/(4.*PI * np->pdot * dtmp); |
134 |
greg |
1.3 |
/* worth using? */ |
135 |
|
|
if (dtmp > FTINY) { |
136 |
|
|
copycolor(ctmp, np->scolor); |
137 |
greg |
2.48 |
dtmp *= omega; |
138 |
greg |
1.3 |
scalecolor(ctmp, dtmp); |
139 |
|
|
addcolor(cval, ctmp); |
140 |
|
|
} |
141 |
|
|
} |
142 |
greg |
2.49 |
if (ldot < -FTINY && ltdiff > FTINY) { |
143 |
greg |
1.3 |
/* |
144 |
|
|
* Compute diffuse transmission. |
145 |
|
|
*/ |
146 |
|
|
copycolor(ctmp, np->mcolor); |
147 |
greg |
2.49 |
dtmp = -ldot * omega * ltdiff * (1.0/PI); |
148 |
greg |
1.3 |
scalecolor(ctmp, dtmp); |
149 |
|
|
addcolor(cval, ctmp); |
150 |
|
|
} |
151 |
greg |
2.2 |
if (ldot < -FTINY && (np->specfl&(SP_TRAN|SP_PURE)) == SP_TRAN) { |
152 |
greg |
1.3 |
/* |
153 |
greg |
1.4 |
* Compute specular transmission. Specular transmission |
154 |
greg |
1.13 |
* is always modified by material color. |
155 |
greg |
1.3 |
*/ |
156 |
|
|
/* roughness + source */ |
157 |
greg |
2.48 |
dtmp = np->alpha2 + omega*(1.0/PI); |
158 |
greg |
1.3 |
/* gaussian */ |
159 |
greg |
2.53 |
dtmp = exp((2.*DOT(np->prdir,ldir)-2.)/dtmp)/(PI*dtmp); |
160 |
greg |
1.3 |
/* worth using? */ |
161 |
|
|
if (dtmp > FTINY) { |
162 |
greg |
1.13 |
copycolor(ctmp, np->mcolor); |
163 |
greg |
2.52 |
dtmp *= np->tspec * omega * sqrt(-ldot/np->pdot); |
164 |
greg |
1.13 |
scalecolor(ctmp, dtmp); |
165 |
greg |
1.3 |
addcolor(cval, ctmp); |
166 |
|
|
} |
167 |
|
|
} |
168 |
|
|
} |
169 |
|
|
|
170 |
|
|
|
171 |
schorsch |
2.47 |
extern int |
172 |
|
|
m_normal( /* color a ray that hit something normal */ |
173 |
|
|
register OBJREC *m, |
174 |
|
|
register RAY *r |
175 |
|
|
) |
176 |
greg |
1.3 |
{ |
177 |
|
|
NORMDAT nd; |
178 |
greg |
2.38 |
double fest; |
179 |
greg |
1.9 |
double transtest, transdist; |
180 |
greg |
2.29 |
double mirtest, mirdist; |
181 |
|
|
int hastexture; |
182 |
|
|
double d; |
183 |
greg |
1.1 |
COLOR ctmp; |
184 |
|
|
register int i; |
185 |
|
|
/* easy shadow test */ |
186 |
|
|
if (r->crtype & SHADOW && m->otype != MAT_TRANS) |
187 |
greg |
2.27 |
return(1); |
188 |
greg |
2.2 |
|
189 |
|
|
if (m->oargs.nfargs != (m->otype == MAT_TRANS ? 7 : 5)) |
190 |
|
|
objerror(m, USER, "bad number of arguments"); |
191 |
greg |
2.29 |
/* check for back side */ |
192 |
|
|
if (r->rod < 0.0) { |
193 |
|
|
if (!backvis && m->otype != MAT_TRANS) { |
194 |
|
|
raytrans(r); |
195 |
|
|
return(1); |
196 |
|
|
} |
197 |
greg |
2.40 |
raytexture(r, m->omod); |
198 |
greg |
2.29 |
flipsurface(r); /* reorient if backvis */ |
199 |
greg |
2.40 |
} else |
200 |
|
|
raytexture(r, m->omod); |
201 |
greg |
1.3 |
nd.mp = m; |
202 |
greg |
2.16 |
nd.rp = r; |
203 |
greg |
1.1 |
/* get material color */ |
204 |
greg |
1.3 |
setcolor(nd.mcolor, m->oargs.farg[0], |
205 |
greg |
1.1 |
m->oargs.farg[1], |
206 |
|
|
m->oargs.farg[2]); |
207 |
|
|
/* get roughness */ |
208 |
greg |
2.2 |
nd.specfl = 0; |
209 |
greg |
1.3 |
nd.alpha2 = m->oargs.farg[4]; |
210 |
greg |
2.2 |
if ((nd.alpha2 *= nd.alpha2) <= FTINY) |
211 |
|
|
nd.specfl |= SP_PURE; |
212 |
greg |
2.40 |
|
213 |
schorsch |
2.45 |
if ( (hastexture = (DOT(r->pert,r->pert) > FTINY*FTINY)) ) { |
214 |
greg |
2.29 |
nd.pdot = raynormal(nd.pnorm, r); /* perturb normal */ |
215 |
greg |
2.41 |
} else { |
216 |
greg |
2.29 |
VCOPY(nd.pnorm, r->ron); |
217 |
|
|
nd.pdot = r->rod; |
218 |
|
|
} |
219 |
greg |
2.42 |
if (r->ro != NULL && isflat(r->ro->otype)) |
220 |
|
|
nd.specfl |= SP_FLAT; |
221 |
greg |
1.13 |
if (nd.pdot < .001) |
222 |
|
|
nd.pdot = .001; /* non-zero for dirnorm() */ |
223 |
greg |
1.3 |
multcolor(nd.mcolor, r->pcol); /* modify material color */ |
224 |
greg |
2.29 |
mirtest = transtest = 0; |
225 |
|
|
mirdist = transdist = r->rot; |
226 |
greg |
2.30 |
nd.rspec = m->oargs.farg[3]; |
227 |
greg |
2.38 |
/* compute Fresnel approx. */ |
228 |
greg |
2.51 |
if (nd.specfl & SP_PURE && nd.rspec >= FRESTHRESH) { |
229 |
greg |
2.38 |
fest = FRESNE(r->rod); |
230 |
|
|
nd.rspec += fest*(1. - nd.rspec); |
231 |
|
|
} else |
232 |
|
|
fest = 0.; |
233 |
greg |
1.3 |
/* compute transmission */ |
234 |
greg |
1.1 |
if (m->otype == MAT_TRANS) { |
235 |
greg |
1.3 |
nd.trans = m->oargs.farg[5]*(1.0 - nd.rspec); |
236 |
|
|
nd.tspec = nd.trans * m->oargs.farg[6]; |
237 |
|
|
nd.tdiff = nd.trans - nd.tspec; |
238 |
greg |
2.2 |
if (nd.tspec > FTINY) { |
239 |
|
|
nd.specfl |= SP_TRAN; |
240 |
greg |
2.5 |
/* check threshold */ |
241 |
greg |
2.25 |
if (!(nd.specfl & SP_PURE) && |
242 |
|
|
specthresh >= nd.tspec-FTINY) |
243 |
greg |
2.5 |
nd.specfl |= SP_TBLT; |
244 |
greg |
2.29 |
if (!hastexture || r->crtype & SHADOW) { |
245 |
greg |
2.2 |
VCOPY(nd.prdir, r->rdir); |
246 |
|
|
transtest = 2; |
247 |
|
|
} else { |
248 |
|
|
for (i = 0; i < 3; i++) /* perturb */ |
249 |
greg |
2.19 |
nd.prdir[i] = r->rdir[i] - r->pert[i]; |
250 |
greg |
2.7 |
if (DOT(nd.prdir, r->ron) < -FTINY) |
251 |
|
|
normalize(nd.prdir); /* OK */ |
252 |
|
|
else |
253 |
|
|
VCOPY(nd.prdir, r->rdir); |
254 |
greg |
2.2 |
} |
255 |
greg |
1.14 |
} |
256 |
greg |
1.1 |
} else |
257 |
greg |
1.3 |
nd.tdiff = nd.tspec = nd.trans = 0.0; |
258 |
greg |
1.1 |
/* transmitted ray */ |
259 |
gregl |
2.36 |
if ((nd.specfl&(SP_TRAN|SP_PURE|SP_TBLT)) == (SP_TRAN|SP_PURE)) { |
260 |
greg |
1.3 |
RAY lr; |
261 |
greg |
2.50 |
copycolor(lr.rcoef, nd.mcolor); /* modified by color */ |
262 |
|
|
scalecolor(lr.rcoef, nd.tspec); |
263 |
|
|
if (rayorigin(&lr, TRANS, r, lr.rcoef) == 0) { |
264 |
greg |
1.14 |
VCOPY(lr.rdir, nd.prdir); |
265 |
greg |
1.1 |
rayvalue(&lr); |
266 |
greg |
2.50 |
multcolor(lr.rcol, lr.rcoef); |
267 |
greg |
1.1 |
addcolor(r->rcol, lr.rcol); |
268 |
greg |
1.9 |
transtest *= bright(lr.rcol); |
269 |
|
|
transdist = r->rot + lr.rt; |
270 |
greg |
1.1 |
} |
271 |
greg |
2.11 |
} else |
272 |
|
|
transtest = 0; |
273 |
greg |
2.2 |
|
274 |
greg |
2.29 |
if (r->crtype & SHADOW) { /* the rest is shadow */ |
275 |
|
|
r->rt = transdist; |
276 |
greg |
2.27 |
return(1); |
277 |
greg |
2.30 |
} |
278 |
|
|
/* get specular reflection */ |
279 |
|
|
if (nd.rspec > FTINY) { |
280 |
|
|
nd.specfl |= SP_REFL; |
281 |
|
|
/* compute specular color */ |
282 |
greg |
2.38 |
if (m->otype != MAT_METAL) { |
283 |
|
|
setcolor(nd.scolor, nd.rspec, nd.rspec, nd.rspec); |
284 |
|
|
} else if (fest > FTINY) { |
285 |
|
|
d = nd.rspec*(1. - fest); |
286 |
|
|
for (i = 0; i < 3; i++) |
287 |
|
|
nd.scolor[i] = fest + nd.mcolor[i]*d; |
288 |
|
|
} else { |
289 |
greg |
2.30 |
copycolor(nd.scolor, nd.mcolor); |
290 |
greg |
2.38 |
scalecolor(nd.scolor, nd.rspec); |
291 |
|
|
} |
292 |
greg |
2.30 |
/* check threshold */ |
293 |
|
|
if (!(nd.specfl & SP_PURE) && specthresh >= nd.rspec-FTINY) |
294 |
|
|
nd.specfl |= SP_RBLT; |
295 |
|
|
/* compute reflected ray */ |
296 |
|
|
for (i = 0; i < 3; i++) |
297 |
|
|
nd.vrefl[i] = r->rdir[i] + 2.*nd.pdot*nd.pnorm[i]; |
298 |
|
|
/* penetration? */ |
299 |
|
|
if (hastexture && DOT(nd.vrefl, r->ron) <= FTINY) |
300 |
|
|
for (i = 0; i < 3; i++) /* safety measure */ |
301 |
|
|
nd.vrefl[i] = r->rdir[i] + 2.*r->rod*r->ron[i]; |
302 |
greg |
2.53 |
checknorm(nd.vrefl); |
303 |
gregl |
2.36 |
} |
304 |
|
|
/* reflected ray */ |
305 |
|
|
if ((nd.specfl&(SP_REFL|SP_PURE|SP_RBLT)) == (SP_REFL|SP_PURE)) { |
306 |
|
|
RAY lr; |
307 |
greg |
2.50 |
if (rayorigin(&lr, REFLECTED, r, nd.scolor) == 0) { |
308 |
gregl |
2.36 |
VCOPY(lr.rdir, nd.vrefl); |
309 |
|
|
rayvalue(&lr); |
310 |
greg |
2.50 |
multcolor(lr.rcol, lr.rcoef); |
311 |
gregl |
2.36 |
addcolor(r->rcol, lr.rcol); |
312 |
|
|
if (!hastexture && nd.specfl & SP_FLAT) { |
313 |
|
|
mirtest = 2.*bright(lr.rcol); |
314 |
|
|
mirdist = r->rot + lr.rt; |
315 |
greg |
2.30 |
} |
316 |
|
|
} |
317 |
greg |
2.29 |
} |
318 |
greg |
1.1 |
/* diffuse reflection */ |
319 |
greg |
1.3 |
nd.rdiff = 1.0 - nd.trans - nd.rspec; |
320 |
greg |
1.1 |
|
321 |
greg |
2.2 |
if (nd.specfl & SP_PURE && nd.rdiff <= FTINY && nd.tdiff <= FTINY) |
322 |
greg |
2.27 |
return(1); /* 100% pure specular */ |
323 |
greg |
2.3 |
|
324 |
gregl |
2.36 |
if (!(nd.specfl & SP_PURE)) |
325 |
|
|
gaussamp(r, &nd); /* checks *BLT flags */ |
326 |
greg |
2.2 |
|
327 |
greg |
1.3 |
if (nd.rdiff > FTINY) { /* ambient from this side */ |
328 |
greg |
2.50 |
copycolor(ctmp, nd.mcolor); /* modified by material color */ |
329 |
greg |
2.5 |
if (nd.specfl & SP_RBLT) |
330 |
|
|
scalecolor(ctmp, 1.0-nd.trans); |
331 |
|
|
else |
332 |
|
|
scalecolor(ctmp, nd.rdiff); |
333 |
greg |
2.50 |
multambient(ctmp, r, hastexture ? nd.pnorm : r->ron); |
334 |
greg |
1.2 |
addcolor(r->rcol, ctmp); /* add to returned color */ |
335 |
|
|
} |
336 |
greg |
1.3 |
if (nd.tdiff > FTINY) { /* ambient from other side */ |
337 |
greg |
2.50 |
copycolor(ctmp, nd.mcolor); /* modified by color */ |
338 |
|
|
if (nd.specfl & SP_TBLT) |
339 |
|
|
scalecolor(ctmp, nd.trans); |
340 |
|
|
else |
341 |
|
|
scalecolor(ctmp, nd.tdiff); |
342 |
greg |
1.1 |
flipsurface(r); |
343 |
greg |
2.32 |
if (hastexture) { |
344 |
|
|
FVECT bnorm; |
345 |
|
|
bnorm[0] = -nd.pnorm[0]; |
346 |
|
|
bnorm[1] = -nd.pnorm[1]; |
347 |
|
|
bnorm[2] = -nd.pnorm[2]; |
348 |
greg |
2.50 |
multambient(ctmp, r, bnorm); |
349 |
greg |
2.32 |
} else |
350 |
greg |
2.50 |
multambient(ctmp, r, r->ron); |
351 |
greg |
1.1 |
addcolor(r->rcol, ctmp); |
352 |
|
|
flipsurface(r); |
353 |
|
|
} |
354 |
greg |
1.3 |
/* add direct component */ |
355 |
|
|
direct(r, dirnorm, &nd); |
356 |
greg |
1.9 |
/* check distance */ |
357 |
greg |
2.29 |
d = bright(r->rcol); |
358 |
|
|
if (transtest > d) |
359 |
greg |
1.9 |
r->rt = transdist; |
360 |
greg |
2.29 |
else if (mirtest > d) |
361 |
|
|
r->rt = mirdist; |
362 |
greg |
2.27 |
|
363 |
|
|
return(1); |
364 |
greg |
2.2 |
} |
365 |
|
|
|
366 |
|
|
|
367 |
greg |
2.38 |
static void |
368 |
schorsch |
2.47 |
gaussamp( /* sample gaussian specular */ |
369 |
|
|
RAY *r, |
370 |
|
|
register NORMDAT *np |
371 |
|
|
) |
372 |
greg |
2.2 |
{ |
373 |
|
|
RAY sr; |
374 |
|
|
FVECT u, v, h; |
375 |
|
|
double rv[2]; |
376 |
|
|
double d, sinp, cosp; |
377 |
greg |
2.34 |
int niter; |
378 |
greg |
2.2 |
register int i; |
379 |
greg |
2.13 |
/* quick test */ |
380 |
|
|
if ((np->specfl & (SP_REFL|SP_RBLT)) != SP_REFL && |
381 |
|
|
(np->specfl & (SP_TRAN|SP_TBLT)) != SP_TRAN) |
382 |
|
|
return; |
383 |
greg |
2.2 |
/* set up sample coordinates */ |
384 |
|
|
v[0] = v[1] = v[2] = 0.0; |
385 |
|
|
for (i = 0; i < 3; i++) |
386 |
|
|
if (np->pnorm[i] < 0.6 && np->pnorm[i] > -0.6) |
387 |
|
|
break; |
388 |
|
|
v[i] = 1.0; |
389 |
|
|
fcross(u, v, np->pnorm); |
390 |
|
|
normalize(u); |
391 |
|
|
fcross(v, np->pnorm, u); |
392 |
|
|
/* compute reflection */ |
393 |
greg |
2.5 |
if ((np->specfl & (SP_REFL|SP_RBLT)) == SP_REFL && |
394 |
greg |
2.50 |
rayorigin(&sr, SPECULAR, r, np->scolor) == 0) { |
395 |
greg |
2.2 |
dimlist[ndims++] = (int)np->mp; |
396 |
greg |
2.34 |
for (niter = 0; niter < MAXITER; niter++) { |
397 |
|
|
if (niter) |
398 |
|
|
d = frandom(); |
399 |
|
|
else |
400 |
|
|
d = urand(ilhash(dimlist,ndims)+samplendx); |
401 |
|
|
multisamp(rv, 2, d); |
402 |
|
|
d = 2.0*PI * rv[0]; |
403 |
gwlarson |
2.37 |
cosp = tcos(d); |
404 |
|
|
sinp = tsin(d); |
405 |
greg |
2.34 |
rv[1] = 1.0 - specjitter*rv[1]; |
406 |
|
|
if (rv[1] <= FTINY) |
407 |
|
|
d = 1.0; |
408 |
|
|
else |
409 |
|
|
d = sqrt( np->alpha2 * -log(rv[1]) ); |
410 |
|
|
for (i = 0; i < 3; i++) |
411 |
|
|
h[i] = np->pnorm[i] + d*(cosp*u[i] + sinp*v[i]); |
412 |
|
|
d = -2.0 * DOT(h, r->rdir) / (1.0 + d*d); |
413 |
|
|
for (i = 0; i < 3; i++) |
414 |
|
|
sr.rdir[i] = r->rdir[i] + d*h[i]; |
415 |
|
|
if (DOT(sr.rdir, r->ron) > FTINY) { |
416 |
|
|
rayvalue(&sr); |
417 |
greg |
2.50 |
multcolor(sr.rcol, sr.rcoef); |
418 |
greg |
2.34 |
addcolor(r->rcol, sr.rcol); |
419 |
|
|
break; |
420 |
|
|
} |
421 |
|
|
} |
422 |
greg |
2.2 |
ndims--; |
423 |
|
|
} |
424 |
|
|
/* compute transmission */ |
425 |
greg |
2.50 |
copycolor(sr.rcoef, np->mcolor); /* modified by color */ |
426 |
|
|
scalecolor(sr.rcoef, np->tspec); |
427 |
greg |
2.8 |
if ((np->specfl & (SP_TRAN|SP_TBLT)) == SP_TRAN && |
428 |
greg |
2.50 |
rayorigin(&sr, SPECULAR, r, sr.rcoef) == 0) { |
429 |
greg |
2.8 |
dimlist[ndims++] = (int)np->mp; |
430 |
greg |
2.34 |
for (niter = 0; niter < MAXITER; niter++) { |
431 |
|
|
if (niter) |
432 |
|
|
d = frandom(); |
433 |
|
|
else |
434 |
|
|
d = urand(ilhash(dimlist,ndims)+1823+samplendx); |
435 |
|
|
multisamp(rv, 2, d); |
436 |
|
|
d = 2.0*PI * rv[0]; |
437 |
gwlarson |
2.37 |
cosp = tcos(d); |
438 |
|
|
sinp = tsin(d); |
439 |
greg |
2.34 |
rv[1] = 1.0 - specjitter*rv[1]; |
440 |
|
|
if (rv[1] <= FTINY) |
441 |
|
|
d = 1.0; |
442 |
|
|
else |
443 |
gwlarson |
2.37 |
d = sqrt( np->alpha2 * -log(rv[1]) ); |
444 |
greg |
2.34 |
for (i = 0; i < 3; i++) |
445 |
|
|
sr.rdir[i] = np->prdir[i] + d*(cosp*u[i] + sinp*v[i]); |
446 |
|
|
if (DOT(sr.rdir, r->ron) < -FTINY) { |
447 |
|
|
normalize(sr.rdir); /* OK, normalize */ |
448 |
|
|
rayvalue(&sr); |
449 |
greg |
2.50 |
multcolor(sr.rcol, sr.rcoef); |
450 |
greg |
2.34 |
addcolor(r->rcol, sr.rcol); |
451 |
|
|
break; |
452 |
|
|
} |
453 |
|
|
} |
454 |
greg |
2.8 |
ndims--; |
455 |
|
|
} |
456 |
greg |
1.1 |
} |